Document text
MHI
Copy 3 FM 11 _ 25
WAR DEPARTMENT
FIELD MANUAL
AIRCRAFT WARNING SERVICE
August 3, 1942
REFERENCE USE
ONLY
NOT TO BE TAKEN FROM LIBRARY
REGRAOED UNCLASSIFIED**
authorjtyofDODDIR.5200. 1R
FM 11-25
C 1
SIGNAL CORPS
FIELD MANUAL
AIRCRAFT WARNING SERVICE
Changes [ WAR DEPARTMENT,
No. 1 j Washington, March 10, 1043.
FM 11-25, August 3, 1942, is changed as follows :
■ 34? Reporting Platoon
* *****
6. Operating detail and power-plant detail. — The reporting
platoon * * * the power-plant detail. The personnel of
these two details are responsible for the actual installation and
operation of the mobile radar equipment. They are also re-
sponsible for accomplishing' minor repairs, adjustments, and
replacements (maintenance in first echelon) and such more
extensive repairs, adjustments, and replacements (mainte-
nance in second echelon) as may be accomplished by use of
hand tools and the mobile equipment issued to the unit. The
operating detail * * * supply truck K-31.
* . * * * * * *
[A. G. 062.11 (3-1-43).] (C 1, Mar. 10. 1943.)
By Order oj? the Seceetaby of Wak : t
G. C. MARSHALL,
Chief of Staff.
Official :
J. A. ULIO,
Major General,
The Adjutanl General.
U. 8. GOVERNMENT PRINTING OFFICE, IB4S
FM 11-25
SIGNAL CORPS
FIELD MANUAL
j»
AIRCRAFT WARNING SERVICE
UNITED STATES
GOVERNMENT PRINTING OFFICE
WASHINGTON : 1942
>m
WAR DEPARTMENT,
Washington, August 3, 1942.
FM 11-25, Signal Corps Field Manual, Aircraft Warning
Service, is published for the information, and guidance of all
concerned.
[A. G. 062.11 (6-11-42).]
By order op the Secretary of War:
G. C. MARSHALL,
Chief of Staff.
Official :
J. A. ULIO,
Major General,
The Adjutant General.
Distribution:
D (2); IC and H (10).
(For explanation of symbols see FM 21-6.)
ii
TABLE OF CONTENTS
Chapter 1. General. Paragraphs Page
Section I. Purpose, definitions, and refer-
ences 1-3 1
II. Missions, functions, and responsi-
bility 4-7 2
Chapter 2. Organization.
Section I. General 8 6
II. Factors affecting organization 9 6
III. Military units 10-27 8
IV. Nonmilitary agencies 28-29 19
Chapter 3. Observation systems.
Section I. Mechanical 30-35 22
II. Nonmechanical 36-37 29
III. Messages and their transmission 38-41 34
TV. Installation of information and
filter centers 42-48 38
Chapter 4. Signal communication systems.
Section I. General 49-56 47
II. Communication installation 57-62 51
Chapter 5. Operations.
Section I. Operation of information and filter
centers 63-94 53
II. Duties of information and filter
center personnel 95-111 72
Appendix. Model forms 94
Index 109
FM 11-25
SIGNAL CORPS FIELD MANUAL
AIRCRAFT WARNING SERVICE
CHAPTER 1
GENERAL
Paragraphs
Section I. Purpose, definitions, and references 1-3
II. Missions, functions, and responsibility 4-7
Section I
PURPOSE, DEFINITIONS, AND REFERENCES
■ 1. Purpose. — The purpose of the manual is to outline the
Aircraft Warning Service and its agencies, to prescribe its
mission and the responsibilities of various agencies concerned,
to describe its functions, to cover the organization of its agen-
cies, the observation and signal communication systems, and
to prescribe operating procedures for the service. Variations
from standard equipment and procedure are authorized where
such variations are made mandatory by local conditions. This
manual is based upon Field Service Regulations (FM 100
series) and is supplementary to FM 24-5 and FM 11-5.
■ 2. Definitions. — a. Aircraft Warning Service. — The Air-
craft Warning Service is an organization, the chief function
of which is to supply early information of enemy aircraft in
the form desired by the interceptor commander.
b. Interceptor commander. — The interceptor commanders
are responsible for the protection of their respective terri-
torial commands by denying the use of air space to hostile
aviation.
c. Information center. — The information center is a military
installation in a region to which all reports of observations or
detections of aircraft entering or operating in the area are
submitted for identification. It is operated so that rapid
identification of hostile aircraft will be made and the proper
action employed to intercept and attack the enemy prior to
the accomplishment of his mission.
d. Nonmilitary agencies. — Agencies composed of volunteers,
organized by civilian defense councils for the purpose of aiding
the Aircraft Warning Service.
2-5 SIGNAL CORPS FIELD MANUAL
e. Passive air defense. — Passive air defense takes place at
the surface objective or area against which the enemy's air
operations are directed. It includes all measures taken to
render surface objectives less susceptible to hostile observa-
tion or bombardment, to control and protect personnel and
material, and to restrict any activity that constitutes a direct
aid to the enemy.
/. Active air defense. — Active air defense takes place in the
air space through which enemy aircraft move. It is provided
by aircraft, principally interceptor pursuit; projectiles fired
from the ground by antiaircraft artillery; and obstacles,
principally barrage balloons. Active air defense may take
either of two forms; local air defense or general air defense.
g. Local air defense. — Local air defense provides air defense
for a specific objective or relatively small area.
h. General air defense. — General air defense provides for
the defense of the air space over a relatively large area which
contains a number of potential objectives.
■ 3. Further Reference. — a. The publications listed below
contain general or specific reference to the subject of Aircraft
Warning Service:
FM 11-5, Missions, Functions, and Signal Communi-
cation in General.
FM 24-5, Signal Communication.
b. For a complete list of War Department training publica-
tions, see FM 21-6.
Section II
MISSIONS, FUNCTIONS, AND RESPONSIBILITY
■ 4. Missions. — The mission of the Aircraft Warning Service
is to observe the movement of aircraft and to collect and
exhibit the information obtained.
■ 5. Functions. — The functions of the Aircraft Warning
Service are —
a. The organization and training of suitable military ob-
servation units, both permanent and mobile, and nonmilitary
observation agencies; the installation, operation, and mainte-
nance of observing equipment.
b. The provision of suitable signal communication systems
for the transmission of information and orders; the prescrip-
tion of proper forms of messages and a procedure for trans-
AIRCRAFT WARNING SERVICE 5-6
mitting them; the installation, operation, and maintenance
of the signal communication, system, except such parts of the
communication system as may be prescribed elsewhere in
this manual, and those covered by other directives and
circulars.
c. The provision of suitable information centers for the
collection and exhibition of information in the form desired
by the interceptor commander, and the operation and main-
tenance of such centers.
d. The coordination of the Aircraft Warning Service with
other communication and intelligence services of the Army,
Navy, and other Government agencies and commercial
companies.
e. Assistance to establish agencies in the development of
equipment and supplies required for the Aircraft Warning
Service.
■ 6. Responsibility. — a. Air defense in time of war is the
responsibility of the air defense commander. In the present
emergency, defense commands have been organized with air
forces as an integral part of each. The interceptor command
of the air force is charged with the defense of the air space
over the defense command. For a more complete picture of
organization, see figure 1. For aircraft warning activities,
the interceptor command is the basic organization. The
headquarters of interceptor commands are so organized and
trained as to be able to function as the headquarters of a
defensive aviation task force in any theater of operation.
b. The commanding general of each air force is responsible
for the organization arid training of the headquarters of a
fixed air force echelon, this fixed echelon to remain in the
air force headquarters at all times. Through the head-
quarters for the fixed echelon, the commander exercises
command and control over air bases and other fixed air force
installations in his area. In the absence of the mobile
forces, the fixed echelon of the air force commands and
controls the axed Aircraft Warning Service.
c. An interceptor commander is charged with the re-
sponsibility for the air defense of an area that has been
normally divided into air defense regions. He decentralizes
tactical control of pursuit units and Aircraft Warning Serv-
6
SIGNAL CORPS FIELD MANUAL
ice units to regional commanders. The interceptor com-
mander is responsible for the disposition of the active de-
fense forces throughout the entire area, for the designation
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of region boundaries, and for the tactical reinforcement
of one region by interceptor pursuit forces from another
region when the situation necessitates.
d. Nonmilitary agencies for passive defense organization
AIRCRAFT WARNING SERVICE 6-7
are not the responsibility of regional commanders. For
the purpose of setting up and operating fixed Aircraft Warn-
ing Service in the United States, civilian volunteers will
be used in large numbers. A regional signal officer, with an
appropriate Signal Corps detachment or unit, will be set
up in each region in the United States. A general guide
for the procurement and organization of nonmilitary per-
sonnel on a voluntary basis with reference to the law, opinion,
and War Department policy is enunciated in AR 5-100 and
620-10.
e. Organization for, or conduct of, a general air defense
which includes the proper organization of an Aircraft Warn-
ing Service is the responsibility of the interceptor command.
The interceptor commander is charged with the air defense
of an area, and is responsible for such coordination with
passive defense agencies as will result in the establishment
of sound policies for the elimination of direct aids to the
enemy. The interceptor commanders and their designated
agencies have sole responsibility for initiating orders for
blackouts, radio silence, and the discontinuance of any ac-
tivity which may assist an enemy in navigating to his
objective. 3
f. The organization, training, and operation of the civilian
air raid warning system within the continental United States
is handled through the Office of Civilian Defense, which in
turn develops, under the guidance of the commanding gen-
eral of the defense command, the organization, training,
and operation methods employed by the various agencies.
The Signal Corps provides trained cadres to be employed at
fixed filter and information centers manned by civilian
personnel, provided by the Office of the Civilian Defense.
■ 7. Military Observers. — Military observer personnel of all
arms and services must at all times work together to the
fullest extent, and become personally acquainted with the
problems, conditions, and operation of neighboring units.
If the Aircraft Warning Service is to function efficiently,
each unit and the military personnel within each unit must
be responsible for a definite phase of information concern-
ing hostile plane flights, and this information must be trans-
mitted clearly, accurately, speedily, and in a prescribed
form.
471935°— 42 2 5
8-9 SIGNAL CORPS FIELD MANUAL
CHAPTER 2
ORGANIZATION
Paragraphs
Section I. General 8
II. Factors affecting organization 9
in. Military units 10-27
IV. Nonmilitary agencies 28-29
Section I
GENERAL
■ 8. Definitions. — The following terms used in this chapter
are peculiar to the organization of military units and non-
military agencies. The terms are defined in the sense in
which they are used herein.
a. Radar is a term used to designate radio sets SCR-268,
SCR-270, and similar equipment.
b. Filter centers receive, plot, and filter reports of hostile
and friendly aircraft, and immediately transmit the filtered
information to information centers. In some cases, filter
centers are control centers for active defense troops, and
distributing centers for warnings to district warning centers
in their filter areas.
c. Observation post, visual and aural, is a point properly
located and equipped with a telephone, to which are assigned
two or more observers.
Section II
FACTORS AFFECTING ORGANIZATION
■ 9. Factors Affecting Organization. — a. The factors affect-
ing organization of the Aircraft Warning Service employed
within a certain area will depend upon the extent and im-
portance of the area to be defended, the number of critical
areas contained therein, and the method of defense to be
employed.
b. The Aircraft Warning Service is an integral part of an
interceptor command. In addition to the Aircraft Warning
Service, the air defense command will include such of the
6
AIRCRAFT WARNING SERVICE 9
following components as may be necessary: Interceptor pur-
suit aviation, antiaircraft artillery, and civil defense organi-
zations. In general, the Aircraft Warning Service is or-
ganized as follows:
(1) Observation stations from which observers report the
number, type, height, and direction of flight of all aircraft
seen or heard.
(2) Radar stations which are operated by Signal Corps
units for the purpose of supplying accurate information of
the position of both friendly and enemy planes. The radar
is tactically controlled by the interceptor commander or his
representative through the radar office. The supply and in-
stallation of signal and reporting equipment and the training
of related personnel are the responsibility of the unit signal
officer.
(3) Filter centers to which all reports of observers are
transmitted and there plotted and filtered.
(4) An information center to which the filtered reports
from the filter centers are transmitted, plotted, evaluated,
and the necessary action taken.
(5) A communication system consisting of telephone, tele-
typewriter, radio, or any other means of signal communication
tying these various agencies together, and allowing free and
rapid intercommunication.
c. No one system of Aircraft Warning Service is applicable
to all areas under all conditions. For example, the fixed air
defense system in the United States can be more elaborate
than the system used in an oversea theater of operations.
d. For a complete picture of the functions of an air defense
command, the following applies: A given area is set up as an
air defense area; this area will be under the command of
the commanding general, interceptor command; all agencies
utilized in this air defense are directly under the tactical
control of the interceptor commander. The interceptor com-
mander may divide the area into regions. The Aircraft Warn-
ing Service of the two or more regions is so organized as to
be mutually exclusive, each to collect aircraft operational
information for the information center of the region it covers.
Each regional commander is made responsible for the air
defense of his region. The available interceptor pursuit forces
are allocated to the several regions, and come directly under
9-10 SIGNAL CORPS FIELD MANUAL
the tactical control of regional commanders (who are" repre-
sented by regional control officers) . Regional control officers,
acting for regional commanders, will alert and release pursuit
units, commit pursuit forces to interceptions, and supervise
the exercise of ground control during interceptions. The
regional commander controls the tactical operation and em-
ployment of the aircraft artillery units in his region to insure
coordination, and to permit the most effective defense of the
region. The Aircraft Warning Service keeps the regional
controller continuously informed as to the number, type, and
track of aircraft reported flying in his region.
e. The Aircraft Warning Service must function efficiently
since the proportion of successful interceptions increases as
the time consumed In reporting, filtering, plotting, calculating,
and issuing orders decreases. Radar tracking devices serve
to decrease this time and will therefore increase the propor-
tion of successful interceptions.
/. In view of the fact that developments during a hostile air
attack might necessitate the interceptor commander reinforc-
ing certain regions with interceptor pursuit aircraft from
other regions, it is essential that he be kept continually in-
formed of the situation throughout his entire air defense area.
In order to do this, it is necessary that an operations board be
established at the command post of the interceptor command
on which the general situation throughout the entire air
defense area is depicted. This command post should be cen-
trally located with respect to the area requiring air defense,
and with respect to the "center of gravity" of enemy opera-
tions. Communications are provided for the transmission of
information from the several regions to the operations board
at the interceptor command headquarters, and for the issu-
ance of necessary orders and instructions by the interceptor
command to the several region commanders.
Section III
MILITARY UNITS
■ 10. General. — a. For aircraft warning activities, the inter-
ceptor command is the basic organization. Supervision of
the training of Signal Corps troops with the Army Air Forces
involves two separate types of work. The first is the Aircraft
8
AIRCRAFT WARNING SERVICE 10
Warning Service units, and second, the troops engaged in
supplying administrative communication and maintenance to
Signal Corps communication equipment.
b: Aircraft Warning Service troops are divided fundamen-
tally into two types of units, fixed units and mobile units. The
fixed units are known as frontier units, for example, signal
reporting company, frontier, and signal plotting company,
frontier. These units operate fixed communication apparatus
in previously prepared positions, including information and
filter centers organized throughout the United States with the
aid of civilian groups. It is contemplated that these units will
never leave the location to which they are originally assigned.
During peacetime, and as long in wartime as is practicable,
the fixed installation is augmented by the facilities available
to the mobile units. Whenever the mobile unit is operating
with an aircraft unit, the senior Air Corps (pilot) officer com-
manding the interceptor pursuit unit is in charge of aircraft
warning activity in that area. The regional signal officer is
subordinate to the interceptor unit commander whenever the
interceptor unit commander is in the region. When how-
ever, there are no interceptor command units in the area, the
regional signal officer is in charge of all the fixed installations.
His area of responsibility, the region, is served by an informa-
iton center that is manned by a signal plotting company, air-
craft warning, frontier. The signal plotting company merely
provides the cadre of instructors necessary to complete the
training of civilians who do the actual plotting and other
work at the information centers. The plotting company also
furnishes the instructor groups for each of the filter centers
established in the region.
c. In addition to the civilian observation system which func-
tions through commercial telephone communications, the
signal reporting company, aircraft warning, frontier, pro-
vides radar reports. The SCR-270's, semipermanently in-
stalled in previously prepared positions, provide long range
military reporting in the region. The antiaircraft SCR-268's
will be used in an emergency to furnish radar reports, similar
to the SCR-270's. The radar reports from antiaircraft units
to information center can be utilized in the process of ob-
servation.
10-13 SIGNAL CORPS FIELD MANUAL
d. One signal aircraft warning regiment, and, when neces-
sary, one signal aircraft warning battalion, separate, are gen-
erally assigned with each interceptor pursuit . group in an
interceptor command. This assignment is based on air allot-
ment of one group of interceptor pursuit aviation to each air
defense region. It provides for the establishment of a number
of air defense regions for aircraft warning defense in each
interceptor command. With the assignment of each addi-
tional group of pursuit aviation to the interceptor command,
there should be a corresponding assignment of aircraft warn-
ing regiments.
■ 11. Military Units. — The Signal Corps units assigned to
the Aircraft Warning Service are of 16 types, so organized as
to perform aircraft warning tasks required for passive or
active defense. The charts, figures 2 to 10, inclusive, are to
be Used only as guides.
■ 12. Signal Aircraft Warning Regiment. — The signal air-
craft warning regiment (T/O 11-411) consists of a headquar-
ters and headquarters company (T/O 11-412) , a plotting bat-
talion (T/O 11-415), a reporting battalion (T/O 11-425), and
a medical detachment (T/O 11-411). (See fig. 2.) The air-
craft warning regiment has three long-range and seven short-
range radar units. These are divided into one long-range and
two short-range units per company of the reporting battalion.
The headquarters and headquarters company of the reporting
battalion has the seventh short-range unit. Operation is
fundamentally based on the so-called close-in (CI) reporting
platoon, which operates one short-range unit, and the distant
reporting (DS) platoon, which operates one long-range unit.
Each reporting platoon is equipped with radio equipment for
submitting its reports to the mobile information centers oper-
ated by the plotting company of the plotting battalion. The
communication company of the plotting battalion operates
and maintains the communication systems of the regiment.
When construction of long wire lines is necessary, a signal
construction battalion will be utilized. The signal aircraft
warning regiment is both a tactical and administrative unit
and as such is an independent organization.
■ 13. Signal Headquarters and Headquarters Company, Air-
craft Warning Regiment. — The signal headquarters and head-
10
AIRCRAFT WARNING SERVICE 13-17
quarters company, aircraft warning regiment (T/O 11-412) ,
consists of a regimental headquarters, a company headquar-
ters, a headquarters company (consisting of regimental head-
quarters platoon and supply platoon) , and a maintenance pla-
toon. (See fig. 2.) This unit is staffed with officer personnel
for coordination and controlling operation of distant and
close-in reporting platoons under supervision of the controller
at the information center. The maintenance platoon is
charged with the repair and operation of the motor vehicles.
■ 14. Signal Plotting Battalion, Aircraft Warning Regi-
ment. — The signal plotting battalion, aircraft warning regi-
ment (T/O 11-415) , consists of a signal headquarters and
headquarters company (T/O 11-416) , a signal plotting com-
pany (T/O 11-417), and a signal communication company
(T/O 11-418) . (See fig. 2.) This unit has the responsibility
of plotting information as transmitted by the reporting agen-
cies according to the methods set forth by the air force com-
mander. For communication company duties see para-
graph 12.
■ 15. Signal Headquarters and Headquarters Company, Plot-
ting Battalion, Aircraft Warning Regiment. — The signal
headquarters and headquarters company, plotting battalion,
aircraft warning regiment (T/O 11-416), consists of a bat-
talion headquarters, company headquarters, battalion head-
quarters section, supply and headquarters section. (See fig.
2.) The duties of this unit consist of administration, suppiy,
and coordination of Signal Corps activities of information
center and filter centers.
■ 16. Signal Plotting Company, Aircraft Warning Regi-
ment. — The signal plotting company, aircraft warning regi-
ment (T/O 11-417) , consists of a company headquarters sec-
tion, supply and transportation section, operating board, radar
board, and intercept board. (See fig. 3). The duties of this
unit are to establish means of plotting information received
from reporting agencies, evaluation of same, and the rapid
relaying of this information to using agencies.
■ 17. Signal Communication Company, Aircraft Warning
Regiment. — The signal communication company, aircraft
warning regiment (T/O 11-418), consists of headquarters
11
17
SIGNAL CORPS FIELD MANUAL
sat
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IS
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III
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12
AIRCRAFT WARNING SERVICE
17-19
platoon (consisting of an administration section and a motor
and supply section), a wire platoon, a message center pla-
toon, and a radio platoon. (See fig. 4.) This unit, although
a component of the plotting battalion, installs, operates,
and maintains communication systems of the aircraft warn-
S/GNAL PLOTTING
COMFANY
A. W. REGT
CT/O II -417 D
|
|
|
CO. HQ.
SEC.
SUPPLY &
TRANSPORT-
ATION SEC.l
OPERATIONS
BOARD
FILTER
BOARD
INTERCEPT
BOARD
DIRECTION
FINDING
BOARD
Figure 3. — Signal plotting company, aircraft warning regiment.
ing regiment within the limitations of its personnel and
equipment.
■ 18. Signal Reporting Battalion, Aircraft Warning Regi-
ment. — The signal reporting battalion, aircraft warning
regiment (T/O 11-425) , consists of a headquarters and head-
SlGNAL
COMMUNICATIONS
COMfHWy
A.W. REGT.
CT/b 11-418)
HQ.
PLAT.
WIRE
PLAT.
MSG. CEN.
PLAT.
RADIO
PLAT.
J
Figure 4. — Signal communications company,
regiment.
aircraft warning
quarters company (T/O 11-426) and three reporting com-
panies (T/O 11-427). (See fig. 2.) For duties of reporting
companies, see paragraph 20.
■ 19. Signal Headquarters and Headquarters Company, Re-
porting Battalion, Aircraft Warning Regiment. — The signal
headquarters and headquarters company, reporting bat-
471935° — 42-
13
19-21
SIGNAL CORPS FIELD MANUAL
talion, aircraft warning regiment (T/O 11-426) , consists of
a battalion headquarters, headquarters platoon (consisting
of a company headquarters, a supply and transportation
section, and a battalion headquarters section) , a repair pla-
toon (consisting of a wire repair section and a radio repair
section) , and a short range intelligence platoon. (See fig.
2.) The headquarters and headquarters company of the
reporting battalion is so organized that it can provide for
and administer to personnel who, in combat, are scattered
over wide areas, and it also contains specialists trained for
specific duties with the Aircraft Warning Service.
■ 20. Signal Reporting Company, Aircraft Warning Regi-
ment. — The signal reporting company, aircraft warning
SIGNAL CO.
REPORTING
A.W.REGT.
Ct/0 11-427}
HQ
PLATOON
HQ.
SECTION
DISTANT
RPTG. PLT.
CLOSE IN
RPTG. PLT
CLOSE IN
RPTG, PLT,
SUPPLy
SECTION
TRANSP.
SECTION
Figure 5. — Signal reporting company, aircraft warning regiment.
regiment (T/O 11-427), consists of a headquarters platoon
(a headquarters section, a supply section and a transporta-
tion section) , a distant reporting platoon, and two close-in
reporting platoons. (See fig. 5.) The organization is ar-
ranged to permit platoons to carry on simultaneously aircraft
warning activities over widely separated areas. Each platoon
functions as a team.
■ 21. Signal Headquarters and Headquarters Company, Air-
craft Warning Service, Interceptor Command. — The signal
headquarters and headquarters company, Aircraft Warning
Service, interceptor command (T/O 11-450-1) , consists of an
interceptor signal officer section, an administration section,
14
AIRCRAFT WARNING SERVICE
21-23
a supply and transportation section, a message center sec-
tion, a plotting section, a radio section, and a telephone and
telegraph section. (See fig. 6.) This unit is so organized as
to control all Aircraft Warning Service facilities in an area
under control of the commanding general of the interceptor
command. This company also provides message center per-
sonnel and men for the operation of the commanding gen-
eral's "operation board." This board includes the territory
of all the regions under the control of interceptor commander
and overlaps into the adjacent air defense area.
HO, t HQ. CO.
A. If. S.
INTERCEPTOR COMD.
ct/o I1-JS0-O
INTERCEPTOR
SIGNAL
OFFICER
SECTION
ADMIN.
SECTION
SUPPLY
AND
TRANSP.
SECTION
PLOTTING
SECTION
RADIO
SECTION
TELEPHONE
AND
TELEGRAPH
SECTION
MESSAGE
CENTER
SECTION
Fictjke 6. — Headquarters and headquarters company, aircraft
warning, interceptor command.
■ 22. Signal Aircraft Warning Battalion, Separate. — The
signal aircraft warning battalion, separate (T/O 11-445) , con-
sists of a headquarters and headquarters company (T/O
11-446), a plotting company (T/O 11-447), two reporting
companies (T/O 11-448) , and a medical detachment. (See
fig. 7.) The signal battalion, aircraft warning, separate,
operates in the same manner as the signal aircraft warning
regiment except that it has 14 distant reporting platoons
divided into two companies. The functions of the plotting
company and communication company are carried out by
the plotting company of the aircraft warning battalion.
■ 23. Signal Headquarters and Headquarters Company, Air-
craft Warning Battalion, Separate. — The signal headquarters
15
23-26 SIGNAL CORPS FIELD MANUAL
and headquarters company, aircraft warning battalion (T/O
11-446), consists of a battalion headquarters, a company
headquarters, a battalion headquarters section, a supply and
transportation section, and a repair section. (See fig. 8.)
This unit is organized so as to coordinate signal activities in
the information center. Trained specialists of this unit are
required for second echelon repair of Signal Corps equipment.
■ 24. Signal Plotting Company, Aircraft Warning Bat-
talion, Separate. — The signal plotting company, aircraft
warning battalion (T/O 11-447), consists of a headquarters
platoon (consisting of a company headquarters section and
a supply and transportation section) , a plotting platoon, and
a communication platoon consisting of a radio section and a
wire section. (See fig. 7.) This unit is organized so as to
carry out activities relative to the plotting and display of
information received from reporting agencies in connection
with the Aircraft Warning Service.
■ 25. Signal Reporting Company, Aircraft Warning Bat-
talion, Separate. — The signal reporting company, aircraft
warning battalion, separate (T/O 11-448) , consists of a
headquarters platoon (consisting of a company headquarters
and a supply and transportation section) , and seven distant
reporting platoons. (See fig. 7.) This unit is so organized
that the platoons can function as a team over a wide area
for the purpose of reporting information as desired by the
air defense commander.
■ 26. Signal Plotting Company, Aircraft Warning Fron-
tier. — The signal plotting company, aircraft warning,
frontier (T/O 11-467), consists of a regional signal officers
section, a company headquarters, an administration platoon,
a supply platoon, a filter platoon, an information center
platoon, a ground observation platoon, and a medical detach-
ment. (See fig. 9.) This unit is organized so as to carry
out aircraft warning activities of a region consisting of three
filter centers and an information center with personnel avail-
able for three reliefs. The ground observers platoon refers
to military personnel only, and is not concerned with the
civilian observers organized by local government. The med-
ical detachment personnel of this unit will also care for the
needs of the reporting companies, aircraft warning, frontier.
16
AIRCRAFT WARNING SERVICE
26
26
SIGNAL CORPS FIELD MANUAL
HQ. * HQ. COMPANY
SIGNAL BH.
A. W.(SEPARATE~)
(T/O II-44B)
1
BH. HQ.
SECTION
CO. na.
SUPPLY S
TRANSPORTATION
SECTION
REPAIR
SECTION
Figure 8. — Signal headquarters and headquarters company, aircraft
warning battalion, separate.
SIG. CO. PLOTVNG
A. Uf. FRONTIER
CT/O 11-467 J
REGIONAL
SIGNAL
OFFICER
SECTION
COMPANY
Ha.
ADMINS.
PLATOON
FILTER
PLATOON
INF. CEN.
PLATOON
GRD. OBSV.
PLATOON
SUPPLY
PLATOON
Figure 9. — Signal plotting company, aircraft warning, frontier.
SIG. CO. PPT.
A. W. FRONTIER
(T/O II-46B}
COMPANY
HQ.
SUPPLY AND
TRANSP. sec.
REPORTING
SECTION
REPORTING
PLATOON
Figure 10. — Signal reporting company, aircraft warning, frontier.
18
aircraft warning service 27-29
■ 27. Signal Reporting Company, Aircraft Warning,
Frontier. — The signal reporting company, aircraft warning,
frontier (T/O 11-468), consists of a company headquarters,
a supply and transportation section, and three reporting
platoons (see fig. 10) . This unit is organized to furnish
complete teams for reporting aircraft activities in connection
with the Aircraft Warning Service.
Section IV
NONMILITARY AGENCIES
■ 28. General. — a. The United States has been divided into
air defense areas, and these defense areas are further divided
into warning districts. The warning district is a unit of
civilian air raid warning systems, and a message transmitted
to any warning district will always apply to the whole of the
district, and that district alone. It is highly important that
a message for one warning district should not become known
to persons in another district. Messages of warning will be
dispatched from the point of origin to the various warning
districts one at a time, as each district becomes threatened
by the progress of a raid.
b. In order to have the information centers and filter cen-
ters function efficiently, nonmilitary personnel will be trained
in the operation of telephones, telephone switchboards, tele-
typewriters, indicating devices, and the various apparatus
and equipment used at filter centers and information centers;
that is, filter boards, operation boards, intercept boards,
radar boards, etc.
c. Personnel for nonmilitary positions will be obtained by
volunteers from various organizations, such as fraternal,
civic, and service clubs until the formation of a Women Auxil-
iary Army Corps makes paid, uniformed female personnel
available. Not only from the viewpoint of conservation of
man power, but for efficiency, the employment of women in
filter and information centers is indicated. Military person-
nel should be limited to essentia] instructors, supervisors, and
other key personnel.
■ 29. Training Nontechnical Personnel. — a. Personnel of in-
formation and filter centers will receive instructions in plot-
ting and telling as a group. A complete descriptive picture
19
29 SIGNAL CORPS FIELD MANUAL
of the basic operations of these centers will be a valuable aid
to the individual. During this preliminary part of their in-
struction, the information and filter center personnel should
learn to work together as a team. No attempt will be made
at first to instruct them in the details of the duties of other
personnel of the centers, although such a knowledge is highly
desirable to allow for temporary replacements and in order
that they can provide assistance to one another in rush pe-
riods. Any changing of duties should be deferred until each
member has become so expert in his own duties that efficient
team work is almost automatic. Collective training must
consist of a progressive series of exercises which should even-
tually include all operations in all the various Aircraft Warn-
ing Services which together make up the complete informa-
tion and filter center. It is important that training of the
personnel of a center take place in the established informa-
tion center or filter center. Collective training exercises
should rarely last more than an hour, and should be followed
by a conference at which the personnel taking part may have
their attention drawn to mistakes.
b. During the first phase of training, suitable messages to
afford practice to the control room staff should be prepared
beforehand, exactly in the form in which they would be deliv-
ered from the ground observers, and telephoned to the control
room at intervals of time controlled by the officer in charge
of instruction. At the outset, a single message should be
dealt with step by step, ample time being allowed for full
explanation of procedure. Gradually, the situation revealed
by the messages should be made increasingly complicated and
difficult to deal with, and the rate at which messages are
received should be increased. It should, however, be remem-
bered that under actual operations, the message handling
capacity will limit the number of messages received from
observers. Results which are both discouraging and false
may result if excessive hurrying of the trainee is required
during practice. Remember that accurate plotting, filtering,
and telling require the use of trained minds rather than the
mechanical use of trained hands.
c. Nonmilitary agencies should be exploited to provide
civilian personnel for ground observers. Observers are the
personnel reporting movement of aircraft to the information
20
AIRCRAFT WARNING SERVICE 29
or filter centers. The observer's place in the Aircraft Warn-
ing Service is one of exacting service, reauiring definitely
known abilities and qualifications. The observer will be in-
structed to observe certain facts regarding aircraft, record
these facts, and report them immediately by telephone.
The great speed and wide radius of action of aircraft require
that the surveillance of the air by means of observation from
the ground be continuous over extensive areas. Accuracy in
aircraft identification can only be attained by a careful and
thorough study of the characteristics of the different types of
machines in all positions of flights. However, accuracy in
identifying aircraft is not nearly so important to the observer
as accuracy in judging altitude, distance, and direction, and
speed and accuracy in transmitting the information.
471935° — 42 4 21
30-31 SIGNAL CORPS FIELD MANUAL
/
CHAPTER 3
'--OBSERVATION SYSTEMS
Paragraphs
Section I. Mechanical 30-35
.II. Nonmechanical - 3&~37
HI. Messages and their transmission 38-41
IV. Installation of information and Alter centers 42-48
\ A /| A T i Section I
' • , MECHANICAL
0)
<• 30. General. — a. Radar. — This means of observation is the
function of reporting platoons, both close and distant. Ob-
servation is made by means of complex electrical apparatus
(radar) operated by highly trained specialists.
b. Ituties. — (1) The radar officer is the representative of
the controller and directs the radar units in tactical operation
from the information center.
(2) The oscilloscope operator interprets the oscilloscope
picture into useful target reports.
(3) The radar plotter at radar locations changes polar
coordinates to grid coordinates for transmission to filter
or information center.
(4) The plotter at the information center with suitable
plotting equipment sets up the information on the radar
board showing time, cours.e, number of planes, etc.
(5) The teller at the information center relays information
from the radar board to the intercept officer or other inter-
ested agency at the information center.
fM~&b. Function. — a. The effective function of the radar unit
remains unimpaired even though the aircraft may be hidden
by smoke, haze, clouds, darkness, or is out of range of the
human eye. For the most part, the elements do not reduce
the effectiveness of radar observation. It is designed to
search for distant aerial targets and, in addition, it supplies
a continuous flow of data which locate aircraft accurately
with a base reference at the detecting unit.
22
AIRCRAFT WARNING SERVICE 31
b. In many cases, radar efficiency is governed by terrain
features. . In selecting a suitable site as a preliminary step,
all available maps should be consulted for natural formations
so that any terrain feature, such as a mountain, which would
mask the beam, can be avoided. The final selection of a site
must, of course, be made from physical reconnaissance, not
from a map. The final decision on suitability can only be
made with a radar installed at the site.
c. The data obtained by radar are transmitted through the
system of signal communication to the information center,
where the regional commander or his representative (con-
troller) can observe the course of hostile aircraft tracked by
the equipment, estimate the situation, and issue such orders
as are deemed necessary to intercept such targets.
d. The radar equipment, both mobile and fixed, will be
employed in a theater of operation as directed by the inter-
ceptor commander. Tactical direction of the radar is the
responsibility of the interceptor commander or his repre-
sentative through the radar officer.
e. Tracking of targets at certain azimuths can be quickly
obtained if the radar plotters have had sufficient training "on
location." Minimum and maximum distances are controlled
through many factors, and a thorough knowledge of equip-
ment on location is valuable for efficiency of operation.
Training on location should be expedited, and all operators
should be given periods of training on the oscilloscope so that
they can quickly become familiar with operation on location.
f. Sectional aeronautical charts (1:500,000) should be used
for plotting because location of targets can be no more accu-
rate than the map.
g. Coordinates of target positions will be transmitted to
information centers in the rectangular coordinates of the
air defense grid system. (See par. 68.) Controllers will in-
form radar officers of the general areas it is desired to cover.
The radar stations will be prepared to carry out all orders
issued to them by the regional radar officer. Radar will be
used for search and track or both. The normal limits of search
for each radar in the region will be prescribed in both azimuth
and range by the region radar officer. In the absence of
specific instructions, the radar will always search over its
normal search area.
23
32-33 SIGNAL OORPS FIELD MANUAL
■ 32. Mobile Radar Installation. — a. Major components. —
The major components of this unit consist of four vehicles:
(1) Power supply truck K-31. — This truck contains a four-
cylinder gasoline engine which drives a 120/208-volt, 60-cycle,
three-phase a-c generator, separately excited by a d-c gen-
erator; and a central power panel containing the necessary
measuring instruments, voltage regulator, overload relays,
and a high-voltage rectifier for transmitter plate power.
(2) Operating truck K-30. — This truck contains a high-
power radio transmitter, a cooling system for the transmitter
tubes, two cathode-ray oscilloscopes (one carried as a spare),
two superheterodyne receivers (one spare), a vacuum-tube
keyer, a plotting table, and containers for spare parts and
tubes.
(3) Antenna mount (.trailer) K—22-B. — This unit is trans-
ported by a prime mover which can be readily coupled or un-
coupled as desired. On the trailer are mounted the main
antenna support or tower, on which the antenna proper is
mounted, the azimuth motors which control the direction and
speed of rotation of the antenna, a power winch for erection
of the antenna tower, and, in addition, a compartment con-
taining all the necessary tools and equipment required to
assemble the antenna ready for operation. The prime mover
has no function in the operation of the equipment after the
antenna mount has been placed on location and the jacks have
been placed.
(4) Stake body truck K-33, — This truck is used to trans-
port the antenna proper, together with certain other pieces
of equipment required for file assembly, installation, and op-
eration of the equipment. Other than for transportation
purposes, the K-33 truck is not required for the operation of
the radar.
b. Additional transportation. — In addition to the equipment
mentioned in a above, there are six vehicles provided for the
additional transportation requirements for personnel and
equipment. These are not directly involved in the operation
of the radar.
■ 33. Location and Unit Arrangement. — a. Due to the char-
acteristics of radar, it is preferable that the location selected
for operation be free from buildings, trees, power lines, and
24
AIRCRAFT WARNING SERVICE
33
other obstructions extending above the base of the antenna
in the area coverage of the equipment.
b. Ideal location of radar equipment presents a problem
which can best be solved by trial method. A hilltop is not
necessarily the best location. The preferred location is one
in which the reporting sector is 180°, and in which the an-
tenna can be placed in front of trees, thus providing a back-
ground which reduces to a large extent the possibility of
observation, since the antenna and the antenna tower is a
frame presenting no large solid surface. The natural cover
provided by the trees makes an exceptionally good location.
The situation and directives from higher authority will govern
to a certain extent the location, but the mission must be com-
TRAILER K-22-B
UNOBSTRUCTED.
VIEW
OPERATIONS TRAILER K-30
Figube 11. — Location of trailers.
pleted even if the equipment has to be located in an exposed
area. The actual arrangement of the antenna mount, the
operating truck, and the power truck should conform to that
shown in figure 11, as closely as the individual location will
permit.
c. When a reporting platoon moves into position, the
platoon commander will select the actual site for the an-
tenna mount first, keeping in mind the fact that the oper-
ating truck will have to be located so as to permit the plotter,
teller, and the oscilloscope operator to have an unobstructed
view of the azimuth indicator. The transmission line cou-
pling and the operating truck to the antenna mount must be
in a straight line.
d. The power supply truck may be placed in any convenient
location within the limits of the power cables; however, con-
25
33-34 SIGNAL CORPS FIELD MANUAL
sideration must be given to the operation and maintenance
of equipment. Sufficient space should be allowed between the
truck units so that personnel can move about freely.
■ 34. Reporting Platoon. — a. Organization. — T/O 11-427
will be used as a guide for personnel assignments within the
platoon.
b. Operating detail and power-plant detail. — The reporting
platoon consists mainly of the operating detail and the power-
plant detail. /The personnel of these two details are responsi-
ble for the actual installation, operation, and maintenance
of the radar equipment. The operating detail consists of the
aircraft warning communication operators, the radio receiver
attendants, and the radio transmitter attendants.^ The oper-
ating detail installs, operates, and maintains the equipment
contained in the operating truck K-30 and the antenna mount
K-22-B. The power plant and rectifier detail provides the
necessary personnel required to set up, operate, and maintain
the gasoline engine, the a-c generators, and the rectifier,
all of which are contained in the power supply truck K-31.
c. Radio detail. — This consists of a sergeant, chief radio
operator, and four privates (radio operators) . This detail,
under the supervision of the sergeant, installs, operates, and
maintains, the radio equipment and other communication
equipment used by the platoon. However, the communication
personnel of a distant reporting platoon is not responsible
for the wire communication to, higher headquarters, nor to
filter or information centers.
d. Guard detail. — Twenty-four-hour guard will be main-
tained on all radar equipment.
e. Transportation detail. — This consists of one sergeant,
truck master; one private, automobile mechanic; and six
privates, chauffeurs. This detail under the sergeant truck
master is responsible for maintenance of all vehicles of the
platoon, and provides six chauffeurs for the vehicles.
(1) Chauffeurs for the stake-body truck K-33, prime mover
K-32, power truck K-31, and operating truck K-30 will be
provided by the personnel of the operating and power-truck
details. The prime mover K-32 should be driven by the most
experienced corporal or private available in these two details,
and he should be assigned to the operating detail. This will
26
AIRCRAFT WARNING SERVICE 34-35
place this cnauffeur-technician in a position in which he is
near the prime mover.
(2) The same practice should be followed in the selection of
the driver for the power truck K-31, but he should be one of
the power plant and rectifier attendants. The driver of the
operating truck K-30 and the stake-body truck K-33 should
be either an aircraft warning operator, a 'radio-receiver at-
tendant, or a radio-transmitter attendant. Chauffeur and
driver must each obtain a Government driver's permit (see
FM 25-10) prior to actual operation of a Government-owned
vehicle.
(3) Personnel arranged to ride with the chauffeur-tech-
nician will be trained in driving, and will have received a
Government permit.
/. Supply detail. — This detail consists of one sergeant who
is the platoon supply sergeant, and one private who is the
platoon supply clerk. This detail is responsible for the pro-
curement, storage, and issue of all platoon supplies, under
the direct supervision of the platoon commander.
g. Mess detail. — The two cooks and one cook's helper install,
operate, and maintain the platoon mess, under the direct
supervision of the junior commissioned officer present who, in
addition to his other duties, will be the platoon mess officer.
■ 35. Installation.— a. After the location of the reporting
platoon has been selected, each vehicle will be moved to the
exact location. No sequence of this movement is given except
that the antenna mount, the operating truck, the power-
supply truck, and the stake-body truck will be given priority,
in the order given, over all other vehicles in the platoon.
b. The actual installation of the radar equipment will be
accomplished by the operating detail and the power-plant
and rectifier detail (see TM 11-1100). The operating de-
tail will be divided into two units for the initial installation :
one unit consisting of two privates, radio-receiver attendants,
and the other unit consisting of the balance of the personnel
of the operating detail. The power-plant detail will remain
as a unit, and their work will consist of making all the
electrical connections between the power-supply truck, the
operating truck, and the antenna mount, and placing the
equipment in the power-supply truck in operation. A four-
27
35 SIGNAL CORPS FIELD MANUAL
man unit, consisting of two receiver attendants and two
transmitter attendants from the operating detail, will set
up the equipment in the operation truck, and the balance
of the operating detail will work on the assembly and the
erection of the antenna.
c. The technical sergeant, aircraft warning chief, will be
charged with the installation of the radar equipment, and,
as such, will necessarily be a highly trained technical man.
All maintenance will be under the supervision of the tech-
nical sergeant, or the staff sergeant of the platoon.
d. Since each unit of the system depends on both of the
other units in its operation, installation will start on each
unit as soon as the proper order has been given, and will
continue until the installation is complete.
e. The power-supply truck detail will install the ground
system between the power-supply truck and the operating
truck; also, this detail will install the connecting cables
between the power-supply truck and the operating truck, and
cables between the operating truck and the antenna mount.
When the ground system and connecting cables have been
installed, the staff sergeant, assistant aircraft warning chief,
will check the ground connections before the- power plant
is placed in operation.
/. The four men assigned to the operating truck will pre-
pare the equipment in the operating truck for operation by
installing the various tubes in their proper sockets, and then
place the receiver and oscilloscope in their respective posi-
tions, and connect. They will then check the water in
the cooling system and replenish if necessary, and after-
ward lay out the transmission line and the transmission-
line supports.
g. The details assigned to the antenna mount will jack
up the mount on support jacks, level the antenna base,
unfold the antenna tower, and secure and assemble the
antenna sections and tuning elements on the tower, and
raise it into position.
h. With power-supply equipment in operation, and the
equipment in the operating truck properly installed and
connected, the technical sergeant, aircraft warning chief,
will have complete charge of initial equipment adjustment
as provided for in the instruction book covering the par-
28
AIRCRAFT WARNING SERVICE 35-36
ticular unit. This does not relieve the platoon commander
of responsibility for the operation of the equipment. He,
therefore, should keep informed as to the progress of the
installation and adjustment of the equipment, and should
be prepared to take such action as is necessary to insure its
rapid installation and adjustment. He should make a final
inspection when the installation is completed, and cause any
necessary correction to be made. Throughout operation, he
should make periodic inspections and corrections of adjust-
ments.
i. The folio wing records will be kept:
(1) The power-plant detail will maintain an accurate rec-
ord of the operation of their equipment. This will include
all information concerning the rectifier, generator, and gas-
oline engine; also, oil, gas, and water consumption.
(2) The operating detail will maintain records of the op-
eration of the equipment. This will include all information
concerning the cooling unit, transmitter, receiver, oscillo-
scopes, keyer antenna, and the tracking of targets.
Section II
NONMECHANICAL
■ 36. General. — a. Nonmilitary agencies. — Organization of
nonmilitary agencies will be governed by AR 5-100 and
AR 620-10. The civilian volunteer agencies will be guided
by the policies instituted by the commanding general, inter-
ceptor command. The regional signal officer, with a suitably
organized unit, will instruct and supervise the operations of
civilian volunteer observation units which are organized in
each region within the United States for passive defense.
b. Definitions. — (1) Observer. — A person whose duty it is
to detect aircraft and report certain information with regard
to such aircraft to the filter center.
(2) Observation post. — A point properly located and
equipped with a telephone, to which are assigned two or
more observers.
(3) Flash message. — A prearranged message of uniform
continuity of text by which observers may transmit vital
information concerning aircraft heard or seen without loss,
of time. (See Form No. 1, par. 1, appendix.)
471935° — 42 5 29
37 SIGNAL CORPS FIELD MANUAL
■ 37. Organization. — a. Preparation for effective air defense
in war requires organization and training in peace. A terri-
torial organization is created that may be expanded quickly
in an emergency to meet the demands of war. The basic
peacetime framework and training should include —
(1) A command agency, interceptor command.
(2) An Aircraft Warning Service with region cadres and
information and filter centers with complete operating equip-
ment, including interior wiring and wire connections to the
commercial telephone system,
(3) A program of training to include as a minimum: peri-
odic training of observers; periodic training of information
and filter center details; continued training of pursuit officers
in the mechanism of interception; periodic operation of air
defense commands with their complete organization of com-
mand and control systems, aircraft warning services, inter-
ceptor pursuit aviation, aircraft representing an enemy, anti-
aircraft artillery, barrage balloons, and air raid warning
systems.
b. Nonmilitary agencies, other than observers, will be guided
by two considerations — the necessity for eliminating direct
aids to the enemy, and for air raid precautions.
c. Nonmilitary agencies will be organized through the co-
operation of civilian defense agencies, based on the plan set
up by the commanding general, intercept or command.
d. Observation systems, nonmechanical, are systems for the
observation of aircraft by selected military personnel in desig-
nated areas, and by all nonmilitary personnel who have volun-
teered their services. Observers transmit, generally through
a telephone communication system using commercial circuits
and in the sequence and form prescribed by the interceptor
command, certain information about aircraft seen or heard
by them to information centers, through filter centers. The
data thus obtained are plotted in a standard form, in order
that the regional commander may estimate the situation, and
issue such orders and instructions as are deemed necessary,
including air raid warnings through the appropriate agencies.
e. The organization of an effective observer system for the
Aircraft Warning Service requires a great deal of time. Ob-
servers should be told as much of the fundamentals of the
Aircraft Warning Service as is not confidential. They should
30
AIRCRAFT WARNING SERVICE 37
be made to understand the vital necessity for their services
and for speed and accuracy in reporting. Their morale and
interest should be stimulated from time to time by personal
contact with representatives of the interceptor command. In-
struction of observers entirely by correspondence is unsatis-
factory. It should be remembered that observers are volun-
teers not operating under close and continual military super-
vision. If their interest is allowed to lag, their value will
decrease proportionately.
/. In actual operation, the observation post will be manned
24 hours a day. Therefore, sufficient volunteers must be desig-
nated for each post to provide a suitable number of substi-
tute observers ready to take the place of any regular ob-
server who through illness or for other reasons is unable to
fulfill his assignment. A schedule of service hours must be
worked out to fit the periods of availability of these volunteers.
Some 12 to 16 observers will generally be required for each
observation post.
g. Volunteer observers will be stationed at appropriate loca-
tions, both in and out of cities, and are to be trained in observ-
ing and reporting to a filter center. This filter center filters
out all nonessential information reported by observers, and
transmits the filtered information to an information center.
h. Both men and women will be used as observers. Men
observers should be beyond selective service age or unfit for
combat duty. Observers should be trustworthy citizens
selected without regard to race, creed, or color, with the time,
ability, and physical capacity to carry out their assignments
faithfully at observation posts. Volunteers must be alert,
careful, and dependable in character. They must have the
diligence to study and learn to recognize, locate, and report
the numerical strength, altitude, and type of aircraft spotted,
direction of their movement, and time of observation.
i. The observation of aircraft consists in reporting speedily
by commercial telephone to a filter center the presence of air-
craft seen or heard from an observation post, their number,
type, altitude, approximate location, and the direction in
which they were headed. It is the observer's responsibility to
get this message to filter center plotters speedily, so that in the
event the observed flight is identified as an enemy target,
31
37 SIGNAL CORPS FIELD MANUAL
steps may be taken to intercept the hostile aircraft and pre-
vent them from completing their mission.
7. The following material will be furnished civilian observa-
tion post organizers. (See appendix for sample forms.)
(1) One small section of map showing the general location
of the observation post to be established (fig. 12) .
(2) Five copies of Form No. 2 (Report of Observation Post
Organizers).
(3) Five copies of Form No. 3 (Instructions for Chief Ob-
servers) .
(4) Three copies of Form No. 4 (Report of Chief Observers) .
(5) War Department penalty envelopes.
(6) Twenty copies of Form No. 5 (Instructions for Ob-
servers) .
(7) Two orientation cards (fig. 20, appendix) .
k. In organizing civilian observation posts, the following
definite and systematic procedure is indicated:
(1) The organizer will be furnished with a map showing
the approximate desired location of the observation post (see
circle within map, fig. 12). It is known from information
furnished by the telephone company that there is at least
one telephone subscribed in the circled area. The observa-
tion post should be located in a quiet place favorable to
observation in all directions and within 15 seconds' walk from
a telephone.
(2) The organizer should investigate the area personally,
select the best place for observation and telephone service
and secure the voluntary use of the premises and telephone
for the observation post.
(3) It is desired that where possible a direct or individual
line telephone be used. If it is impracticable to obtain an
individual line telephone, then a party line may be used.
(4) The observation post should be so located that ob-
servers can reach the telephone within 15 seconds after the
observation of airplanes.
(5) The telephone and premises must be available for
immediate access for day and night service.
(6) All telephone calls made on the telephone selected
pertaining to the operation of the aircraft warning service
in the form of flash messages are charged to and paid for
by the Government.
32
AIRCRAFT WARNING SERVICE
37
(7) If the organizer is unable to secure the volunteer use
of a private telephone and premises, he should see if there
is a nearby organization such as a lodge, fraternal order,
businessman's club, women's club, or municipal agency which
might provide a telephone or an extension to one that may
be used.
Figure 12. — Map for observation post location.
(8) When he has established the location of the observa-
tion post the organizer should place a small cross on the map
at the exact location of the observation post within the circle.
This map should be mailed with two completed copies of
Form No. 2, with the telephone number, name, and address
of the subscriber, to the regional signal officer. This tele-
phone will be the only one used by the observers of this
33
37-38 SIGNAL CORPS FIELD MANUAL
post for reporting planes. Copies of Form No. 2 can be
obtained from the regional signal officer.
(9) A chief observer should be selected who will agree to
organize a sufficient number of observers to maintain a con-
tinuous day and night watch with two observers on duty at
all times.
(10) With the aid of the chief observer, the organizer
should select two or three assistant chief observers to act in
the absence of the chief observer and supervise the watches
when active operations are being conducted.
(11) The organizer should execute all five copies of Form
No. 2 and mail two completed copies, with the map on which
the location of the observation post is marked, to the regional
signal officer. The remaining three copies of Form No. 2
• will be disposed of as follows :
1 copy for the files of the State defense council.
1 copy for the files of the observation post organizer.
1 copy for the files of the chief observer.
(12) Form No. 3 will be distributed as follows:
1 copy for the observation post organizer.
1 copy for the chief observer.
3 copies for the assistant chief observers.
(13) The confidential code name of each observation post
will be sent to the .organizer after the observation post has
been organized and his report received by the headquarters
of origin of forms.
Section m
• - MESSAGES AND THEIR TRANSMISSION
'■-3fk Flash Message. — a. In order to save every possible
second, to reduce the time lag in the reporting of aircraft to
the filter center, and to insure that the essential information
is transmitted in the most concise and expedient manner,
the flash type of message is used. (See par. 124, FM 11-5.)
It is important that every observer practice the preparation
and telephoning of flash message with absolute minimum
loss of time after the airplanes have been observed. (See
Form No. 1, appendix.)
b. The information contained in the body of the flash
message must be transmitted in sequence of the numbered
34
AIRCRAFT WARNING SERVICE 38
vertical columns. Each column must be checked or filled
in to correspond with the information the observer has
obtained. All of the information must be transmitted in
accordance with a definite procedure.
c. The observation post is shown on a map at the filter
center, and when a report is received the filter center knows
that aircraft were seen or heard near the observation post
reporting. As other observation posts report in succession,
it is possible to determine that speed and course and to con-
firm information previously received about the observed air-
craft. Very accurate information as to the location of
aircraft is needed to permit accurate tracking. It is nec-
essary that the observer report the direction and distance of
the airplanes with reference to the observation post when
observed.
Column 6 of Form No. 1 gives the direction, and column 7
gives the distance. When the airplanes are directly over the
observation post, the report will be "Overhead."
d. The following detailed information relates to the flash
message (Form No. 1).
Column 1. In this column the observer either underlines
the appropriate word or gives the exact number, depending
upon his observation. He must not delay the report to get
the exact number. He should try to count the airplanes,
but if they cannot be counted quickly he should give his best
estimate.
Column 2. It is very difficult to identify airplanes. One of
the easiest identifiable characteristics is the number of mo-
tors. If the airplanes are seen, the observer should use one
of the three designations in the column. If the number of
motors cannot be observed, he should report all small air-
planes as single motor and all large ones as multimotor.
Column 3. The observer underlines the appropriate word
corresponding to his observation. "Very high" and "Very
low" are extremes. When the airplanes are so high they are
barely visible or cannot be seen he should report "Very high."
He should report "Very low" when the airplanes are just above
the trees or ground. Airplanes are "low" when all of their
details and markings are clear; "high" when the windows,
markings, etc., cannot be seen. The observer should give his
best estimate without delay.
35
38-39 SIGNAL CORPS FIELD MANUAL
Column 4. The observer underlines whether the airplanes
were seen or heard.
Column 5. The code name of the observation post should
be written in column 5 when the observer goes on watch.
The code name will be assigned the observation post when
organized.
Column 6. The observer indicates the direction of the air-
planes from the observation post when they were seen or
heard. The observer should orient himself as to directions
as soon as he reports for duty. If the airplanes cannot be
seen he should make his best estimate of the direction.
Column 7. The observer should indicate the distance of
the airplanes seen or heard from the observation post. It
will help if he picks out visible objects or landmarks whose
distance from the observation post is known. These objects
should be compared with the location of the aircraft for dis-
tance. When he cannot see the airplane the observer should
estimate its distance; his best estimate is better than the
commander's guess.
Column 8. The observer should indicate the direction in
which the airplanes are traveling or headed. If he is prop-
erly oriented, this should not be difficult.
■ 39. Observer's Procedure. — The following is a detailed list
of operations for each observer going on duty:
a. He should fill in several message blanks in advance with
the information to be indicated in line 1 and column 5.
b. He should take up a position at the observation post
most favorable to see or hear airplanes.
c. Immediately when airplanes are seen or heard, he
should note mentally all the details called for in columns 1, 2,
3, 4, 6, 7, and 8. He should not wait to fill in the flash
message form but should rush to the telephone at the ob-
servation post, and call or dial the operator. When the
operator says, "Number, please," he should reply "Army
flash," followed by the telephone number of the observation
post.
d. The observer should speak slowly and distinctly, di-
rectly into the mouthpiece of the telephone.
e. When the central operator hears the words "Army
flash," the telephone operator immediately starts a high
36
AIRCRAFT WARNING SERVICE 39^41
priority, Government collect long-distance call to the Army
filter center. While the operator is doing this, the observer
Should underline or otherwise properly fill in the flash mes-
sage form. He should be ready to give the flash message
when an Army operator answers and says, "Army, go ahead,
please."
/. When the Army operator says, "Army, go ahead,
please," the observer starts giving his flash message. He
should talk in an even tone, speaking as distinctly as possible.
He should not talk too fast. He should start the flash
message by saying "Army flash" followed by the proper
words marked or entered in columns 1 to 8, inclusive, on the
flash message form.
g. When he has finished his flash message, the observer
should wait until the Army operator has said "Check, thank
you." When the Army operator says, "Check, thank you,"
he should hang up at once in order to clear the lines for
other messages.
h. After he has hung up, the observer should retain
the flash message form he has transmitted, and later hand
it to the chief observer for file. The chief observer keeps
a record of all actual flash messages sent.
■ 40. Speed in Reporting. — Speed in reporting an observed
flight is of extreme importance. It is assumed that the ob-
server has started to telephone his report within 15 seconds
after making the observation. It is of extreme importance
that as little time as possible be consumed in observation of
aircraft, getting to the telephone, and starting the flash
message. The telephone personnel are trained especially to
handle reports and have also established a minimum time
by special telephone procedure. If the observer can do his
part in 15 seconds or less, a very short over-all time will be
required from observation to the Army information center.
■ 41. Identification. — As an aid to instruction for proper
identification of airplanes, the regional signal officer will
prepare identification charts for distribution to observation
posts when possible. Reference should be made to FM 30-
30, 30-31, 30-34, 30-35, 30-38, and 30-39.
471935° — 42 6 37
42 SIGNAL CORPS FIELD MANUAL
Section IV
INSTALLATION OP INFORMATION AND FILTER
CENTERS
■ 42. Installation. — The following instructions relate to the
establishing of an information center:
a. General. — The design and lay-out of information centers
should be drawn around the operations room (see fig. 13).
This room is normally located centrally with respect to the
space available. It always contains an operations board
(or map) , a radar board, and a status board, all on a large
scale. It may contain such other boards or maps as may be
found advantageous in utilizing the available space. When a
primary or alternate filter center is directly associated with
the information center, it is desirable that the operations room,
the filter room, and the intercept room be grouped closely
together and constitute an operating block. When practica-
ble, this entire block should be located centrally with respect
to the space available. Offices, equipment rooms, etc., can
be arranged around and outside the operating block. Such
an arrangement makes for more efficient tactical operations,
decreases cost, requires a minimum of special ventilating
equipment, and facilities sound proofing. When prac-
ticable, provision should be made for easy access by control
personnel to platforms overlooking adjoining filter boards
and intercept boards when these boards are a part of the
information center.
b. Mezzanine floor. — Whenever practicable, the operation
board should be surrounded on three sides by an overhanging
mezzanine floor. When this is impracticable, a raised plat-
form should be provided to insure a good view of the opera-
tions board, the radar board, status board, and other displays,
by those primarily concerned. Provisions should be made for
air circulation on the platform or mezzanine floor in rear
of personnel disposed to view the several displays below.
It is desirable that the floor of the platform or mezzanine
be covered with sound deadening material so that the noise
level may be kept to a minimum. When practicable, as
much of the platform or mezzanine as is occupied by the
control officer, pursuit officer, radio A officer, and radar
officer, should be entirely inclosed and made soundproof with
38
AIRCRAFT WARNING SERVICE
42
aoswH3dns
aooid
39
42 SIGNAL CORPS FIELD MANUAL
access doors, and glassed off from the main floor below.
The radio A officer should be provided with a reasonably
soundproof cabin, with glass overlooking the operations well,
and glass on the side toward the pursuit officer and control
officer. Local conference with agencies providing liaison
officers will give a reasonably good index of their space re-
quirements, and will facilitate the pay-out of positions on
the mezzanine or platform. It is desirable to provide a
narrow, short, flat surface on the mezzanine, extending
backward from the operations well between the controller
and the pursuit officer, and install thereon such switches and
controls as may be in common use by both. This will de-
crease equipment requirements, and facilitate operations by
avoiding mutual interference. Suitable map-boards should
be provided in the form of partitions or partial partitions
for the several liaison officers. Suitable wall display space
should be provided for all control personnel on which weather
maps, special instructions, and other data may be displayed.
For the control officer, pursuit officer, and radar officer,
display space should be provided in the rear of their posi-
tion. Fluorescent lights should be utilized and should be so
placed and directed as to avoid shadows on working or display
surfaces. Control officers' position should directly face the
vertical radar board in line with the center of the operations
board. The radar officer and the pursuit officer should be
on either side of and adjacent to the control officer. The
radio A officer should be next to the pursuit officer. The
air raid warning officer and the antiaircraft artillery liaison
officer should, when practicable, be as near the radar officer
as local arrangements permit. It is desirable in general that
the air raid warning officer, the Federal Communications
Commission liaison representative, and the antiaircraft artil-
lery liaison officer be grouped together. The Civil Aeronau-
tics Administration representative and the Army liaison
officers should be grouped together when practicable.
c. Operations room. — Sufficient space should be provided
around the operations board to permit personnel to sit when
not actually engaged in plotting. The radar plotters, radar
tellers, floor supervisor, and status board plotters must work
on the operations room floor. This causes considerable con-
gestion, and careful consideration must be given to each lay-
40
AIRCRAFT WARNING SERVICE 42
out to insure adequate working space. On the other hand, it is
undesirable that displays be spread too far apart. Each lay-
out can be made only when the space available is known.
When practicable, it is highly desirable to provide forced
ventilation to all parts of the operation block as a great num-
ber of persons are required to work in a very confined space.
d. Operations board. — The operations board for fixed in-
stallations should be made of wood, with a y 8 -inch plywood
top, carefully joined and sanded smooth. The surface should
be not less than 26 inches nor more than 34 inches high, de-
pending upon the height of the ceiling. A height from 30
inches to 32 inches is best. A suitable wood frame and brace
construction should be used. No point on any board should be
over 8 feet from at least one plotter. Subject to this limita-
tion, the scale of the map should be as large as practicable.
The operations board for the average region will be to the
scale of 1 inch equals 2 miles. One-piece inlaid vulcanized
rubber mats will be provided for operations boards and filter
boards at fixed installations.
e. Radar board. — It is desirable to plot radar reports by
grid coordinates rather than by polar coordinates. The radar
board should, therefore, be entirely covered by the master
grid system. This board should be of as large a scale as
space and plotting difficulties will permit. It should be
mounted vertically, with the top as near the ceiling as
possible, and the bottom high enough to permit unobstructed
view from the control platform or meazanine. This board
should show the maximum coverage of each radar in or
immediately adjoining the region, including inland cover-
age. Radar sites, airdromes, coverage circles, region and
filter area boundary lines, boundaries between radar, and
overlap areas should all be shown in colors conforming
to those used on the operations board. The radar board
is frequently constructed of metal so that magnetized plotting
pips can be used.
/. Status board. — (1) While electrical remote control status
boards are under development, a substitute must be used, and
for this purpose a large blackboard is suitable. On the status
board (fig. 14) a legend column at the left describes the vari-
ous status conditions of the airplanes, such as availability,
activity, and fuel remaining. A column is provided for each
41
42-43 SIGNAL CORPS FIELD MANUAL
squadron, and each squadron column is subdivided into six
element columns. Eighteen horizontal spaces are provided,
each opposite an item in the legend column. The legend
column is divided from top to bottom as follows:
Available 1 .,
Not available (availability
Ready N
Standby
Alert /degrees of readiness
Stations J
Ordered off
In flight
On intercept \
On patrol
On special mlsslon
Sighted enemyj
Returning to land
Landed and refueling
Fuel 1 hour "\
Fuel 3 4 hour
Fuel y 2 hour fuel remaining
Fuel V* hour]
(2) A distance of 3 or 4 inches between horizontal lines
and between adjacent element lines is adequate. Chalk
markings will be used on the status board and therefore
strong light should be provided. The status board should
not be used for anything except immediate iiiformation.
Data as to when aircraft will become available, etc., are kept
by the pursuit officer at his position. A simple X is the only
entry required in any space other than the legend spaces and
the spaces provided for identification of squadron, elements,
and airdromes. It is desirable that the status boars? be as
high as possible so as to permit unobstructed vision lor the
mezzanine personnel.
■ 43. Operations board at command post, interceptor com-
mand. — a. Arrangement. — The interceptor commander,, ok his.
representative on duty, requires the display of —
Information of enemy air movements.
Status of friendly pursuit.
Weather conditions.
42
AIRCRAFT WARNING SERVICE
43
The best general arrangement is the provision of a large
horizontal operations board covering the entire air defense
area, a platform overlooking the operations board, a vertical
FIELD
FIELD
SQUADRON
SQUADRON
ELEMENTS
1
2
3
4
5
6
1
2
3
4
5
6
AVAILABLE
NOT AVAILABLE
READY
STAND BY
ALERT
STATIONS
ORDERED OFF
*
IN FLIGHT
ON INTERCEPT
ON PATROL
ON SPECIAL
SIGHTED ENEMY
RETURNING
TO LAND
LANDED AND
REFUELING
FUEL ONE HOUR
FUEL 3 /4 HOUR
FUEL V Z HOUR
FUEL % HOUR
Figure 14. — Status board.
status board, and a vertical weather board so disposed as to
be readily visible by control personnel. The status board
and the weather board are both outline blackboards on which
43
43 SIGNAL CORPS FIELD MANUAL
suitable entries are made in chalk for instant reference.
They may be mounted in a line or at an obtuse angle to each
other, as determined by the space available.
b. Interceptor command operations board. — This board
should be of the same material and construction as the re-
gional operations boards. It should show mainland and sea
areas, airdromes, regional boundaries, prominent landmarks,
master grid system, and location of region information cen-
ters. The board should be of uniform scale and of such a
size that no point on the board is over 7 feet from at least one
plotter.
c. Status board at interceptor command post. — This should
be identical with the boards provided at regional information
centers, except with reference to the number of units covered.
d. Weather board. — The weather board is an outline map
painted in yellow lines '/i-inch wide on an ordinary black-
board. Meteorological information is displayed on this board
by a code involving colored chalk lines, and letters as follows:
(1) Colors refer to altitude.
Feet
Red 0-500
Green 500-1,000
Yellow 1,000-4,000
Blue 4,000-10,000
White above 10,000
(2) Lines refer to cloud conditions.
Crossed slanting lines — overcast.
Horizontal lines — broken.
Vertical lines — scattered.
(3) Superimposed letters refer to other meteorological con-
ditions.
V — visibility less than 3 miles.
S — snow.
R — rain.
W — wind over 35 miles per hour.
I — icing conditions.
T — extreme atmospheric turbulence.
P — fog or visibility under 1 mile.
e. Platform or mezzanine interceptor command post. — It
is particularly important that a high platform or mezzanine
be provided for overlooking the large operations board be-
44
AIRCRAFT WARNING SERVICE 43-46
cause of the size and scale of the map. The mezzanine
should provide space for not less than five persons, and
should, when practicable, be glassed off from the floor below.
■ 44. Filter Centers. — Filter centers will invariably perform
filtering and air raid warning functions. When necessary or
advisable, antiaircraft artillery, Federal Communications
Commission, and other liaison officers will obtain informa-
tion direct from filter centers, in which case the boards are
classed as primary and alternate, the latter being reduced
in scope and size and materially simplified.
■ 45. Primary Filter Board Room. — Filter rooms are con-
structed and laid out around the filter board. They are
simple installations, consisting essentially of the filter board
and a mezzanine or platform overlooking the board. The
height of the mezzanine above the filter room floor will ordi-
narily be limited by ceiling heights, but should be as near
6 or 7 feet as practicable.
■ 46. Primary Filter Board. — This board is to the scale of
1 inch equals 1 mile whenever practicable, subject only to the
limitation that no part of the board will be over 7 feet away
from each plotter. The table and surface should be outlined
in the same manner as was described for the operations
board. Three plotters are provided for each reporting area,
with alternative capability for receiving information of and
plotting in adjacent areas. Each filter board should cover
the entire filter area, plus at least a 20-mile overlap in all
directions. More overlap may be required where overlap
telling circuits are toll terminals rather than full-talk and
when filter area boundaries are close to important objectives.
The boundaries of reporting areas are determined by esti-
mating the plotting capabilities of three plotters under the
air traffic conditions anticipated. The greater the rate of
enemy air operations, the smaller the reporting area, and
vice versa. Generally speaking, each filter area will consist
of not less than three nor more than seven reporting areas.
The first letter of the code name of the reporting area (not
the grid system) should be painted on the map in the center
of the reporting area, in the same color as the reporting
area boundary. This letter should be 1 foot high, and
471935°— 42 7 45
46-48 SIGNAL CORPS FIELD MANUAL
painted in 2-inch width. Each letter should be oriented
with respect to the teller who reports to the operations
board for the area.
■ 47. Filter Center Mezzanine or Platform. — The platform
overlooking the filter center board should not be glassed
off from the floor below. It should provide ample space for
the tellers, supervisors, and others required in the specific
area. The personnel on the platform will vary with the
nature and location of the filter center. In the case of a
filter center associated with an information center, it is
highly desirable that the mezzanine overlooking the filter
board be an extension of the operations mezzanine, so that
control personnel may have ready access to view the filter
board.
■ 48. Alternate Filter Center. — In order to provide for
alternative means of filtering in the event of failure of any
filter center, alternate filter centers should be provided in
each case. As a general rule, these alternate filter centers
should be associated with an information center or a pri-
mary filter center of another area, and should not require
the provision of an entirely new installation. Alternate fil-
tering facilities should be reduced in scale and scope. Ordi-
narily one or at the most, and exceptionally, two plotters
per reporting area should be provided. In many instances
alternate filter boards can be mounted vertically, and may
be plotted in pencil on an overlay. No specifications for
alternate facilities are prescribed, each lay-out being planned
to meet the requirements of the specific locality and condi-
tion. In general, alternate facilities should be as simple as
practicable, but capable of carrying out primary functions
on a minimum basis.
48
AIRCRAFT WARNING SERVICE 49-52
CHAPTER 4
SIGNAL COMMUNICATION SYSTEMS
Paragraphs
Section I. General 4SMi6
II. Communication installation 57-62
Section I
GENERAL
■ 49. Purpose. — The purpose of this chapter is to clarify the
employment of signal agencies available to the Aircraft
Warning Service.
■ 50. References. — This chapter is based upon Field Service
Regulations (FM 100 series) and is supplementary to FM
24-5 and FM 11-5.
■ 51. Signal Systems. — Signal communication systems as
employed in the Aircraft Warning Service are the same as
those employed in other services, being augmented in certain
operations by the facilities of the commercial telephone sys-
tems in particular locations, and such commercial radio broad-
cast stations as may be of value in the tactical situation.
■ 52. Employment. — The employment of all military signal
communication systems within the Aircraft Warning Service
will conform to the methods and forms promulgated in Army
Regulations and other authoritative directives and publica-
tions; this also applies to the installation, operation, and
maintenance of all equipment. The employment of the com-
mercial telephone facilities will conform to directives and
such other publications as may be issued from time to time
together with certain procedures and methods set forth in
this manual. In the employment of communications in a
fixed installation, the Aircraft Warning Service will follow
a standardized plan so as to simplify operation and training
of operating personnel. Although no two situations will be
exactly the same, especially in areas where mobile units will
function, and in which the communication system must fol-
47
52-54 SIGNAL CORPS FIELD MANUAL
low a plan based upon a clear knowledge of the situation, the
standardized procedure will be followed as closely as pos-
sible. Aircraft Warning Service (fixed installations) com-
munication systems will depend greatly upon commercial
communication facilities. In thickly populated areas, the
communication facilities are generally well set up and de-
pendable. In sparsely settled areas, the communication units
of the Aircraft Warning Service, augmented by the signal
construction battalion, will be relied upon to install, maintain,
and operate complete communication systems.
■ 53. Agencies. — a. In general, agencies of communication
provided will be governed by the tactical situation. All means
of communication necessary to carry out the interceptor
commander's plans will be provided. In all installations, the
communication systems will be as complete as time and
facilities will permit.
b. The principal means of signal communication within the
Aircraft Warning Service will be telephone, augmented where
necessary by teletypewriter, radio telephone, radiotelegraph,
and wire telegraph. The use of teletypewriter should be
limited to administrative purposes and those requiring a
record of transmission and delivery. In the plan of com-
munication for Aircraft Warning Service, due consideration
should be given to the establishment of all means of signal
communication, and a procedure instituted to insure a quick
and rapid conversion of the various means completely, or
in part, so that reliable communications can be maintained.
The following types of communication are provided for:
Telephone.
Teletypewriter.
Telegraph,
Radio.
Panels.
Messenger.
All the various means should be Installed or held in readiness
in order that they may be utilized when required with the
least possible delay.
■ 54. Responsibility. — The responsibility for communication
systems of the Aircraft Warning Service rests with the signal
officer. He has the responsibility of installation, mainte-
48
AIRCRAFT WARNING SERVICE 54-56
nance, and coordination with other units for tactical control
of communication systems. The importance of direct super-
vision must be stressed, for no communication system can
function effectively without complete coordination and
supervision.
■ 55. Coordination. — There must be complete coordination
with other communication systems, such as naval, Govern-
ment, and commercial systems. In large defense areas, the
commercial systems will be utilized to the fullest extent. As
soon as a definite plan has been set up in accordance with the
needs of the defense commander, the unit signal officer will
ascertain what communication systems are available for the
Aircraft Warning Service. He will coordinate (when directed
by higher authority) with other using agencies to determine
the portions of the existing systems that can be utilized to
complete successfully the air warning communication system
without interrupting other activities that are important to
the defense area.
■ 56. Factors Governing Employment of Communication
Equipment. — The means of communication employed will
depend upon the time limit for installation. The unit signal
officer will use judgment in establishing communication sys-
tems so that the system will be ready to function when
needed. It is a known fact that radio communications are
becoming more difficult due to the crowding of the frequency
bands; therefore, radio should be used only as a method of
quick installation of communications, and should be sup-
planted by wire circuits where and whenever possible. The
fact that many restrictions have been placed on the use of
radio for purposes of maintaining secrecy will also govern
its employment. Due to the necessary and extensive use
of communications within a theater of operations due care
must be used in the original lay-out of the system so that
it will be flexible and capable of rapid readjustment to the
needs of the changing situation. The following chart, figure
15, shows type organization of the air force in a theater of
operations. The chart will give an idea as to the number of
units requiring complete communication systems.
49
56
SIGNAL CORPS FIELD MANUAL
9
JfJlMI
sf si
yiu
Si Si Si
\
6
-3,
si
>- s
i
e j
»1
II
3*
5 i
50
AIRCRAFT WARNING SERVICE 57-59
Section II
COMMUNICATION INSTALLATIONS
■ 57. Wire Lines. — As stated, wire lines will be utilized
wherever and whenever possible for communications.
Within the continental United States, commercial wire lines
should be used to the maximum extent feasible for fixed
or mobile installations. In some cases the communication
units of the Aircraft Warning Service will be required to
install additional circuits to augment the commercial cir-
cuits. All units of the Aircraft Warning Service have suffi-
cient equipment and wire for local installation. Certain
situations will call for the establishment of long lines beyond
the possibilities of communication units of the Aircraft
Warning Service; in these situations the signal construction
battalion will be utilized. No unit should be without com-
munication to its superior units, subordinate units, or ad-
jacent units longer than is necessary. The installation and
operation of wire line circuits will follow the instructions of
FM 24-5 and FM 11-5. Due to the rapid changes being made
in technical equipment for telephone communication in the
Aircraft Warning Service, technical operation or installation
will not be taken up in this manual.
■ 58. Teletypewriter. — Teletypewriter is a means of com-
munication used extensively where records of transmission
are required or for administrative communications. Tele-
typewriter circuits can be used for reporting information from
radar stations; providing a suitable circuit with equipment
and trained operating personnel is available, rapid reporting
can be obtained by teletypewriter. In the higher units, tele-
typewriter circuits will be required for various uses; the re-
porting of plane arrivals and departures is essential to the
interceptor and regional commanders. Teletypewriter equip-
ment in series affords an excellent means of reporting in-
formation to several locations simultaneously, thereby leaving
a record for future reference.
■ 59. Telegraph. — The telegraph set TG-5 or TG-5-A will be
used to increase communication channels to outlying units,
and equipment will be made available for simplex circuits.
It may be found that communication over wire lines can be
51
59-62 SIGNAL CORPS FIELD MANUAL
had with the telegraph set TG-5 when the talking circuit is
useless. Refer to TM 11-351 for instructions relative to the
TG-5 and TG-5-A.
■ 60. Radio. — Instructions governing the establishment of all
radio networks, the operating procedure, and the mainte-
nance of radio station records and logs will be found in FM
24-5, FM 24-6, and TM 11-454; for characteristics and use of
radio refer to .PM 11-5. The employment of radio by the Air-
craft Warning Service will be supplementary to the tele-
phone. Telephones are essential to insure speed and accuracy
in transmitting data from an observation post to a filter
center. Other factors which restrict the use of radio are the
small number of noninterfering frequency channels avail-
able, and the requirement of secrecy in transmitting messages.
Where the Aircraft Warning Service is operating in the field,
and the installation of the telephone and teletypewriter lines
has not been completed, the use of radio will for a time be the
principal means of signal communication; however, as soon
as the telephone circuits have been completed between a re-
porting platoon and the filter or information center, that por-
tion of the telephone net will become the principal means of
communication between the two points involved.
■ 61. Panels. — The panel set AP-30-B is issued for fixed in-
stallations of the Aircraft Warning Service, and is used for
communication and identification between ground troops
and aircraft. The care and use of panels is fully covered in
PM24-5.
■ 62. Messenger Service. — Messengers will be used where
essential. The messenger service of the interceptor command
will be well organized, using selected personnel. Messenger
service will not be used where other means of communication
will suffice. This service will be used for the purpose of trans-
mitting bulky matter, such as maps, reports, etc. Such serv-
ice as the Army Air Forces mail plane system and the air
transportation used in the supply system will afford means of
reaching inaccessible locations and greatly facilitate and ex-
pedite the transmittal of necessary matter. The overloading
of messenger service greatly reduces its efficiency; therefore,
a close coordination with other means of transmittal is
essential.
52
AIRCRAFT WARNING SERVICE 63
CHAPTER 5
OPERATIONS
Paragraphs
Section I. Operation of information and filter centers 63-94
II. Duties of information and filter center personnel- 95-111
Section I
OPERATION OP INFORMATION AND FILTER CENTERS
■ 63. General. — a. An area to be defended is divided into
regions. Each region is composed of one or more filter
areas. These, in turn, are divided into smaller reporting dis-
tricts. Filter board plotters are provided for each reporting
district. Their purpose is to receive information from ob-
servation posts and translate the information to the proper
location on the surface of the filter board.
b. Three plotter positions are provided for each reporting
district of the filter board. Their positions are as follows
(see fig. 16) :
No. 1 — in the center of the district.
No. 2 — to the right of No. 1 facing the map.
No. 3 — to the left of No. 1 facing the map.
BELL
ALTERNATE
tt S
FtGxmE 16. — Plotters' positions.
In addition, the immediately adjacent plotter positions of
the two adjoining districts are designated as alternate plot-
ting positions for the district in question.
471935°— 42 8 53
64 signal corps field manual
■ 64. Operation op Telephone Equipment (Filter " Cen-
ter) . — a. Incoming calls will be routed to idle plotters in
sequence as follows: first to No. 1 position, if idle, or if that
position is busy, to the No. 2 position. If both plotters Nos,
1 and 2 are busy, the call will reach plotter No. 3. In case
all three reporting district plotters are busy, the call will
be routed first to alternate position No. 4 in the adjacent
district or, if that is also busy, to alternate position No. 5.
When an incoming call reaches the filter board, the plotter
will receive a zip tone in the headset if the call comes on
the primary line, and a lamp associated with the plotter
answering key will light to indicate the line on which the
call is waiting. If an incoming call comes in on any other
line, the lamp signal only will be received.
b. Plotters are provided with incoming telephone equip-
ment as follows:
(1) No. 1 position has access to one or two incoming lines,
depending on the particular filter board. The position has
a key and associated lamps. To answer the call the plotter
will operate the key in the direction indicated by the lighted
lamp. The upright position of the key is the normal or
disconnect position. On the termination of the call, the
answering key must be returned to normal.
(2) Nos. 2 and 3 positions have access to one, two, or more
than two incoming lines depending on the particular board.
If position has either one or two lines, the operation is similar
to that outlined for No. 1 position. If more than two lines
terminate on the plotter's equipment, the plotter will have a
key and a button set with six buttons and associated lamps.
The upright position of the key will be the normal or discon-
nect position. When answering an incoming call, the answer-
ing key will be operated and the button associated with the
lighted lamp will be depressed. On termination of the call,
if a call is waiting on another line, as indicated by a lighted
lamp, the plotter may depress the associated button without
returning the answering key to normal. If, however, there is
no waiting call, the key must be returned to the normal
position. All lines on the button set should be answered im-
mediately with the exception of those that appear also on
position No. 1. In this case, plotter No. 1 should be answered
by plotter No. 2, and if No. 2 Is busy, No. 3 will take the call.
54
AIRCRAFT WARNING SERVICE
64-65
As plotters Nos. 2 and 3 are the alternate plotters for the
adjoining reporting districts, they will occasionally receive
information that they will have to plot in adjoining reporting
districts.
■ 65. Plotting Equipment. — The following equipment is used
for plotting:
a. Round number disks. — These are marked U (unknown
number) , F (few) , M (many) , 1, 2, 3, .3., (more than 3) , 6, .6.,
9, 10, .10., .15., .20., .25., .30., .40., .50., .75., and .99., and are
used to indicate the number of planes reported. Twenty of
each type disk are located in a bin for use in each reporting
district.
b. Plotting pips. — These pips will be kept in the plotter's
apron. Pips consist of a square block, a five-sided block, and
VL
B
FiGtJBE 17. — Pip for plotting.
an arrow mounted on a single axis. The pip is used as follows:
The five-sided block has sides marked VL, L, H, VH, and U
(meaning very low, low, high, very high, and unknown) and
is used to indicate the altitude reported. The square block
has sides marked U, M, B, and S (meaning unknown, multi-
motor, bimotor, and single engine airplanes) and is used to
indicate the type of plane reported. The arrow has two sides,
one painted green and one painted red (green indicates that
the reported aircraft was seen, and red indicates that it was
heard) . The pip is placed flat on the board so that the direc-
tion of the arrow indicates the direction of flight on the ob-
55
65-67 SIGNAL CORPS FIELD MANUAL
served planes. Figure 17 shows a pip rotated to read, "Bi-
motor planes flying very low and seen."
c. Answering calls. — (1) Answer with, "Army, go ahead
please."
(2) If the answer to (1) above is not the word "Plash"
or "Overlap" (see par. 39a) , you have received a call not
intended lor the Army, and you will then say, "You have
been connected with a wrong number; hang up, please, and
make your call again." Upon this statement, disconnect.
To terminate the call alter the flash message has been
received say, "Check, thank you," and disconnect.
■ 66. Plotting Calls From Observation Post. — a. Form No.
1 is a copy ol the flash message lorm used by observers and
will be read to you over the telephone. An example ol a
received flash message is as lollows: "Flash — 3 — Bimotor —
Very low — Seen — Dudley 20 — NE — 2 — West," meaning, "Three
bimotor planes flying very low were seen 2 miles northeast
ol observation post Dudley 20 flying toward the west."
b. As the above message is being received, the plotter per-
lorms the lollowing operations:
(1) Selects the correct number disk indicating the number
ol planes reported and places it on the filter board.
(2) Rotates the parts ol the pip so that the type ol planes,
altitude ol planes, and whether seen or heard are indicated
on one surface.
(3) Locates the observation post making the report on
the filter board and places the number disk over that post
location.
(4) Places the pip with inlormation lacing upward at the
point on the board indicated by the reported direction and
distance Irom the observation post. Points the arrow in the
direction ol flight; 4- and 6-loot rakes will be provided
in order to reach all points in the reporting district.
■ 67. Plotting Overlap Calls. — Besides plotting calls Irom ob-
servation posts you will receive and plot overlap inlormation
Irom adjoining filter boards and radar boards. This inlor-
mation will be received Irom overlap tellers by plotter No. 3
or No. 2 and will be plotted in the overlap area, the shaded
area 20 miles outside ol your filter boundary. The call will
be received in the following sequence : "overlap," target num-
56
AIRCRAFT WARNING SERVICE
67-68
ber, color of the arrow, location of the arrow (grid co-
ordinates), direction of flight, number of planes, type of
planes, and height of planes. The plotter will plot the in-
formation with the specified colored arrow and place near
the arrow a multisided pip with base on table surface and
pointing upward. The pip will be rotated so that the side
of the square block indicating the type of plane, the side
of the pentagonal block indicating height, and the face
of the arrow (red side meaning enemy, and green side mean-
ing friendly) are in the same horizontal plane.
■ 68. Plotting by Grid Coordinates. — Overlap plots will be
located by using the following system of grid coordinates:
Figure 18 illustrates the location of a point in this manner.
Figure 18. — Grid system.
Areas between grid lines running north and south are indi-
cated by number. Areas between grid lines running east and
west are indicated by name. To read the area in which a
point is located, read north and south grid number first,
then east and west grid name. For example, the point in
figure 18 is located in area 72 Glen. To spot the point in the
area, mentally divide the horizontal and vertical sides of
the area each into 10 equal parts numbered zero to nine.
Using the lower left corner 00, read horizontally the point
at which a vertical projection of the point to be spotted
cuts the horizontal edge of grid area. Then read vertically
the point at which the horizontal projection of the point
to be spotted cuts the vertical side of the grid area. For
example, the exact location of the spot in figure 18 is 72
Glen 73. The position within a grid square is always reported
57
68-70
SIGNAL CORPS FIELD MANUAL
as so many units over and then so many units up. This
sequence (over then up) is never varied. The grid coor-
dinate location of the arrow is always told as the location
of the tail of the arrow for both fixed and mobile radar
boards.
■ 69. Equipment (Filterer) .—Each fllterer will be provided
with a three-pocket apron, a supply of red, green, and blue
arrows, and a fllterer's set. The apron is used to hold the
colored arrows in its three pockets. Colored arrows are used
in place of the pips to show the course of planes. The filter-
Figuke 19. — Target display stand.
er's set includes target display stands and a box of rec-
tangular card indicators. Figure 19 shows the target display
stand.
■ 70. Target Display Stand. — The target display stand has
nine clips. In clips one and two, duplicate cards indicating
height should be placed. Clips three and four hold duplicate
cards showing type of plane or number of planes. Clips five
and six hold duplicate cards indicating target numbers.
Clip nine holds a card indicating enemy or friendly. The
set of card indicators is located on a table in the filter room
and includes —
58
.JRCRAFT WARNING SERVICE 70-71
a. Cards indicating height — VL (very low) , L (low) , H
(high), VH (very high), and U (unknown).
b. Cards designating type of plane by number of motors —
S (single motor), B (bimotor), M (multimotor) , and U
(unknown).
c. Cards showing type of plane, yellow in color — B
(bomber), F (pursuit or interceptor command forces), N
(navy), O (observation), R (reconnaissance), T (miscella-
neous commercial airplanes), X (experimental), IB (indicat-
ing bomber command forces), IN (indicated Navy forces).
d. Cards showing number of planes — 1, 2, 3, .3. (more than
three), 6, .6. (more than six), 9, 10, .10., .15., .20., .25., .30.,
.40., .50., .75., .99., F (few) , and M (many) .
e. Cards indicating enemy or friendly — green (friendly)
and red (enemy) .
/. Cards indicating target — Nos. 1 to 50, inclusive.
g. Blue chips to be attached to top of target number to
indicate that the flight number was assigned in an adjacent
region. When using the yellow cards showing type of plane,
the indicating cards will be used unless type is verified by
the raid clerk. If verified by raid clerk, single letter cards
will be used.
■ 71. System of Filtering. — a. Time is determined by a clock
with the hour hand removed. It is hung in a prominent
position and has each 5-minute space colored consecutively
red, green, and blue; taking any quarter hour commencing
from the quarter, the first 5-minute space is colored red, the
second green, and the third blue. In making filtered plots,
use colored arrows of color similar to sectors of the clock.
That is, if the hand of the clock is in the red space, use
red arrows. The arrows replace the pips used by the plotter
and are placed on the board in the exact location of the
pip to indicate the path of the reported flight. These plots
will be made with arrows which correspond to the color of
time intervals indicated by the clock. If red arrows have
just been used, green arrows will be the next color to be
employed as shown by the clock. Green will be followed
by blue arrows. Tracks indicated on the board will never be
allowed to be more than 15 minutes in length, that is, when
59
71-73 SIGNAL CORPS FIELD MANUAL
an arrow color starts to be duplicated, all arrows of the
duplicated color will be removed from the board.
b. In addition to arrows, use target display stands to
indicate the filtered information describing the target. Only
one stand for each flight will be required and will contain the
latest filter information. Place the stand adjacent to the
most recently placed colored arrow. Display the information
on the stand as described in paragraph 70. When a target
number is assigned by the raid clerk, this information will
come either verbally from the supervisor, or from a plotter
connected with the supervisor. The target number is then
placed in the correct holder on the stand.
■ 72. Method of Filtering. — The filter plotter is charged
with taking the information as supplied by the ground ob-
servers, which appears on the board as plotted by the
plotters, and evaluating this information so that the infor-
mation given by the filtered' track will be as nearly correct
as possible. This operation is necessary as the information
received from the ground observers concerning any one target
will vary. No two persons are able to make the same report
on the observed flight, due to the human element as well as
the different conditions under which the successive observa-
tions are made. For this reason, it is necessary that the
plotter take these varying reports and reduce them by a
process of mental evaluation to the correct report of the
position, direction, height, and composition of the raid. The
deductions made in this process are based upon plain common
sense, a slight knowledge of what an airplane or formation of
airplanes can do, and a knowledge of the normal errors that
are made by observation. Skill in this operation will come
only with practice and experience. A few general rules and
an outline of the mental process can be laid down at this
time but will be changed, corrected, and added to, as ex-
perience is gained in this type of work. Paragraphs 73 to 79,
inclusive, indicate some of the general considerations.
■ 73. Filtering Speed. — Targets will continue across the
board at a fairly constant rate of speed. These speeds will
vary, with present types of equipment, roughly between 150
and 300 miles per hour. Speeds will not change for short
periods but will tend to hold an average over a given length
of time. Therefore, in spite of the fact that successive plots
60
AIRCRAFT WARNING SERVICE 73-77
"coming through show that the speed of the target is jumping
up and down, it is logical to assume that the target is main-
taining a constant speed, and that the changes indicated
on the board are due to delays in the reporting system.
The plotter not only places arrows on the reported position
of the flight, but he may also place additional arrows between
the plotted positions so as to present a better picture of the
path of the raid to the tellers. Thus, he will keep the track
moving smoothly across the board, but he will never place
"fill-in arrows" in front of the latest plot.
■ 74. Filtering Altitude. — In filtering the altitude of the
raid, the above line of reasoning also holds true. That is,
aircraft do not normally make large changes in altitude in
jumps up and down. Therefore, if successive reports come in
indicating a given flight "reporting altitude," as VH, then H,
then VH, then L, then H, this information should be changed
by the filtering process to either H or VH, if no other factors
are present to aid in making the decision. H or VH was.
chosen as the correct altitude for the target by mentally
averaging the altitude of the reports given. If the next series
of reports reads H, VH, H, H, L, L, L, it would indicate that
the flight was losing altitude and that the correct altitude
marker should be L.
■ 75. Filtering Type of Planes. — The decision is much easier
to make in filtering the type of planes observed, because the
aircraft cannot change the number of its engines. There-
fore, the reports should nearly always be the same, except
for the normal mistakes in reporting the information.
■ 76. Filtering Number of Planes. — In the process of deter-
mining the correct number of planes in a formation, the same
lines of reasoning are followed, because again we have a
simple problem of arriving at a logical average from the dif-
ferent reports received. In cases where this decision must be
made, it is better to pick a number higher than the mathe-
matical average, to be on the safe side.
■ 77. Filtering Friend or Enemy. — The identification of a
target as friendly or enemy is not made by the plotter, but
is made by the raid clerk and will be discussed in a later
section.
61
78-81 SIGNAL CORPS FIELD MANUAL
■ 78. Filtering Course. — The determination as to the true
track the target is making on the map is again a process of
averaging between the various spots that are determined by
the position of the plotter's pips. If the line of plotter's pips
advances in one general direction, the chances are very great
that the flight path is along a straight line between the pips.
Some of the pips will be to one side of this line and others
to the other side. The correct line is determined by visual
inspection, using a good average of the number of plots on
each side, the distance of each plot to the side being taken
into consideration. If the line of plots makes a turn, it is
naturally assumed that the flight has turned in the same
manner.
■ 79. Filtering Unknown Data. — In filtering unknown data,
a few other conclusions may be drawn. If the target is heard
and not seen, the number of engines must be listed as un-
known. When the target is heard and not seen, the number
of airplanes can only be stated as few or many, and the
indication is not very reliable. If the target is heard and
not seen during daylight hours, it may be assumed to be above
the lower level of the cloud layer. Therefore, altitude infor-
mation will be fair up to the cloud limit, and unknown above
that limit.
■ 80. Replacing Pip With Arrow. — While the plotter is
making the above decisions about plots of any one track, he
will place the deduced information on the target display stand
and then replace the plotter's pip with an arrow. This arrow
will be placed in the correct position and direction found by
the filtering process. The color of the arrow will correspond
with the clock color code as described in paragraph 71a.
■ 81. Equipment of Turret Supervisor. — The turret super-
visor has a cabinet with a multiple of all army flash lines
incoming to plotters' positions. These lines have lamps and
associated keys. The supervisor also has a key which when
•operating one way will enable him to talk, or the other way,
to listen on the circuit. The key will be marked to show the
direction in which to operate for talking or listening. When
there is an incoming call to a plotter's position, the answering
(white) lamp associated with that line will also light in the
supervisor's cabinet. When the plotter answers, the answer-
62
AIRCRAFT WARNING SERVICE 81-84
tag lamp will go out, and the busy lamp (green) will light and
remain lighted until the plotter disconnects. To answer or
listen in on an incoming call, operate the key associated with
the supervisor's telephone instrument to talking or listening
position, as desired. Then operate the key (in the cabinet) ,
associated with the lighted lamp, toward the lamp.
■ 82. Duties op Turret Supervisor. — It is the duty of the
turret supervisor to see that all calls on the filter board are
answered promptly and plotted correctly. By observation of
the turret equipment the speed with which incoming calls
are answered by the plotters can be determined. It is
essential that no time be lost by having waiting calls. The
supervisor is, therefore, responsible for seeing that calls are
answered immediately. When all plotters are busy, the
supervisor must answer the incoming calls at the turret, and
transmit the information to the next available plotter. The
supervisor must understand plotting technique thoroughly,
and see that correct operating technique is carried out by
the plotters. Thus, the supervisor must monitor calls, and
give instructions when necessary to plotters. Over direct
lines from the raid clerk in the information center, the turret
supervisor receives identification of flights and targets, as-
signment of numbers, or any change on target display stands.
This is passed on to the No. 3 position plotter of nearest area
for necessary changes on filter board.
■ 83. Equipment op Floor Supervisor. — The floor supervisor
will have a six-button key set with lamps, headset, and
buzzer. This equipment has lines to the controller, raid
clerk, and administrative P. B. X. To answer an incoming
call when the answering lamp lights and the buzzer sounds,
depress the button associated with the lighted lamp. In-
coming calls from the administrative P. B. X. are indicated
by the telephone bell, and are answered by depressing the
button associated with the line. To originate a call, depress
the key associated with the desired line. To disconnect,
restore the key to normal position.
■ 84. Duties op Floor Supervisor. — The floor supervisor —
a. Maintains discipline in the Alter room.
5. Is in charge of the filter board under the direction of
the regional signal officer.
63
84-86 SIGNAL CORPS FIELD MANUAL
c. Maintains proper manning of the filter board under the
direction of the regional signal officer.
d. Relays any instructions from higher authority.
e. Maintains a floor supervisor's log in which are recorded
all instructions as passed to the floor supervisor. This log
is to be turned over to the officer in charge for daily check.
■ 85. Tellers to Operations Board. — a. General. — Tellers to
the operations board are located on the balcony overlooking
the filter board. The tellers are connected directly by tele-
phone to operations board plotters. The teller's telephone set
is connected by operating a lever key. The purpose of the
teller is to relay all filtered information from his part of the
filter board to a similar part of the operations board.
b. Information to be told by operations board teller. —
From that part of the board assigned to the teller, the teller
tells each plot, as it is filtered, to the operations board plotter
on the end of the telephone line. The teller will know that a
plot has been filtered when the filterer substitutes a colored
arrow for the plotter's pip. The teller reports also the target
display stand as set up by the filterer. Explanation of the
target stand is found in paragraph 70.
c. Sequence in telling.— (1) Use the following standard
form in telling —
(a) Target number if assigned.
(b) Color of the arrow.
(c) Grid location of the tail of the arrow. (Grid system
is explained in par. 68.)
(d) Direction of flight.
(e) Friendly or enemy identification.
(/) Number of planes.
(SO Type of planes.
(h) Height of planes.
(2) Items (a) and (d) to (g) inclusive, above are read
from the target display stands described in paragraph 70.
An example of telling is: Target 13, red, 72 Klaxen 31, north,
friend, three, bimotor, high; meaning that the plotter of tar-
get No. 13 has placed a red arrow with tail at 72 Klaxen 31
and pointed toward the north, and that there are three
bimotor planes flying high.
■ 86. Tellers To Intercept Board. — a. General. — Tellers to
64
AIRCRAFT WARNING SERVICE 86-88
the intercept board are located on the balcony overlooking
the filter board. For each intercept board, there is one teller
available at the filter board who is connected directly by tele-
phone with the intercept plotter. The teller's telephone is
connected by operating the key.
b. Information to be told. — The intercept plotter will notify
the teller of a particular target number that he wants fol-
lowed. The teller gives all information appearing on the
filter board concerning each new filtered plot of that target.
c. Sequence of telling. — See paragraph 85c.
■ 87. Overlap Teller. — a. General. — There is an overlap
teller for each adjoining filter area. Overlap tellers tell
plotters in adjoining filter areas. Overlap tellers are located
on the balcony of the filter room. The overlap teller's
telephone equipment includes a key, lamp, nonlocking push-
button ringing key. To answer an incoming call when
the lamp lights, operate key. To connect plotter, push
button as indicated on designation strip. To originate a call
to an adjoining filter board overlap teller, operate key and
depress the single push button ringing key for about a second.
b. Information to be told overlap teller. — The teller will
tell all flights that are in the shaded overlap area both
inside and outside of the filter boundary in the sector adjacent
to the filter area to which he is telling. He will not tell
those flights in this area that have just been told to his
board as overlap from the adjacent filter board.
c. Sequence of telling overlap plotter. — First, the teller
gives to the adjoining overlap teller the reporting name of
the area in which the overlap is to be plotted. This is given
in a single word which is the name of the reporting area.
The adjoining overlap teller will connect him to the correct
filter plotter, who will answer, "Army, go ahead, please*."
He then knows that the plotter is ready to plot his telling;
so, he says "Overlap," and then proceeds with telling.
d. Overlap from adjoining filter board. — In case the over-
lap is to be told to the teller's filter board, he will hear the
adjoining Alter board overlap teller give an area name. He
will then operate his key to place the correct filter plotter
into the circuit.
■ 88. Operations Board Plotter. — a. General. — The opera-
65
88 SIGNAL CORPS FIELD MANUAL
tions board is similar to the filter board, but combines all
filter areas of the region to make one large operations board.
A plotter for each filter area on the operations board is con-
nected by direct telephone to a teller located at the filter
board. The plotter plots on the operations board the tracks
that appear on the filter board as told by the teller.
b. Telephone equipment. — Operations board plotters have
telephone headsets, and either one-way or two-way lever keys
with one or two associated lamps. To occupy the position,
connect the telephone set to jacks, and operate the lever-type
key if a one-way key. To answer incoming calls on one-way
key equipment, no further action is required if the lever key
is kept operated. If the key is in the inoperative position,
incoming calls will be indicated by the lighted lamp, and may
be answered by operating the key. Disconnect by returning
lever key to normal only when vacating position. If the
plotter's position has a two-way key, connect the headset in
a similar manner, and answer incoming call by operating
lever key to the normal position. Where more than one
plotter has duplicate connections to the same teller, each
plotter will listen to call, and that plotter who is stationed in
the most advantageous position will plot the call.
c. Plotting equipment for operations board plotter. — The
operations board plotting equipment is described in para-
graphs 69 and 70. In addition to the equipment there de-
scribed, the plotter will have at his position a long and short
rake for assistance in plotting.
d. Method of plotting at operations board. — (1) If not al-
ready connected with the teller, the plotter will answer with
"Go ahead." An example of what the teller will tell the opera-
tions board plotter can be found in paragraph 85c. This in-
formation will be plotted in the same manner as described
in paragraph 70.
(2) The following information will be plotted on the board
in the sequence indicated:
(a) Target number.
(b) Color of arrow.
(c) Grid location.
(d) Direction of flight.
(3) The following items are put on the target display stand:
(a) Friendly or enemy.
66
AIRCRAFT WARNING SERVICE 88-89
(b) Number of planes.
(c) Type of planes.
(d) Height of planes.
(4) When the plotter at the Information board has received
all the information from the teller, and he is sure that he has
received the information correctly, the plotter terminates
the call by saying "Check." Plotters will remove 15-minute-
old plots at the beginning of each 5-minute interval as con-
trolled by the color clock code.
■ 89. Tellers to Intercept Board. — a. General. — Tellers to
the intercept board are located on the balcony overlooking
the operations board. The tellers are connected directly by
telephone to the intercept board. The purpose of the teller
is to relay all enemy target information plotted on either
the operations board or the radar board to the intercept board.
b. Telephone equipment. — The teller's equipment includes
a headset, one-way lever key with associated lamp, and single
push-button ringing key. To occupy position, operate lever
key. To answer, no further action is required if lever key
is in operated position. Incoming calls are indicated by the
lighted lamp and a monotone heard in the receiver. If lever
key is not operated, operate it. To originate a call, lever key
should be operated. Push-button key should be depressed
for about a second to ring.
c. Information to be told to interceptor board. — Tell each
plot of all enemy targets within the regional boundary. Re-
port colored arrows and target display stands as described in
paragraphs 70 and 71.
d. Sequence of telling. — Use the standard form in telling —
(1) Target number if assigned.
(2) Color of the arrow.
(3) Grid location of the tail of the arrow. (Grid system
is explained in par. 68.)
(4) Direction of flight.
(5) Number of planes.
(6) Type of planes.
(7) Height of planes.
An example of telling is: Target 13, red, 72 Klaxen 31, North,
three, bimotor, high; meaning that the target number is 13,
that a red arrow pointing north has been placed at 72 Klaxen
67
89-91 SIGNAL CORPS FIELD MANUAL
31, and that there are three bimotor planes flying high. For
complete operation instructions, refer to paragraph 106.
■ 90. Radar Board Plotters. — a. General. — Radar or radar
board plotters are provided at the radar boards to plot
information on these boards as received from the radar
stations.
b. Telephone equipment. — Each radar plotter position has
a telephone headset, lamp, and one-way lever key and a
single push-button ringing key. To occupy position, con-
nect headset to jacks and operate lever key. To answer call,
no further action is required if lever key is kept in operated
position. Incoming calls are indicated by a lighted lamp
and momentary tone heard in the receiver. To originate a
call, make sure that the lever key is in the operated position;
ring on push-button key for about a second.
c. Plotting equipment, radar plotter. — When a call is re-
ceived, the plotter answers with "Go ahead, please." He
removes a magnetized arrow of color indicated by clock
color code, and places the magnetized arrow on the grid lo-
cation told him on the vertical radar board. He points the
arrow in the direction indicated by the succeeding plot. It
is possible that another radar plotter at his board will be
receiving plots from another radar station on the same
flight. If so, he checks his plots with those of the other, and
arrives at the one course which seems to be correct. The
raid clerk will assign target numbers to the flights appearing
on the radar board. The plotter places the target number
card as designated by the raid clerk under the magnet of one
of the leading arrows of the particular flight. Tracks of
flights shown on the radar hoard should be so marked as to
establish which unit is reporting the flight in question.
■ 91. Radar Teller to Filter Board. — a. General. — The radar
teller to filter board tells radar board plots to the filter board
when they are inside the 20-mile seaward overlap area of the
radar board in order that the flight, as it approaches the
shore, will appear on the filter board.
b. Telephone equipment of radar teller. — The radar teller
to filter board has telephone equipment which includes one-
way lever key, nonlocking push-button keys with designation
strip, and telephone headset. To originate a call, operate
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AIRCRAFT WARNING SERVICE 91-92
the lever key and hold depressed the key associated with
the line to the plotter in the correct area, as indicated on
the designation strip.
c. Information to be told by radar teller. — The land area
of the radar board has marked on the board a 20-mile overlap
into the sea. Each plot, either over the land or in the sea-
ward overlap area, will be told to the filter board over whose
area on the radar board the flight is appearing. The color
of the arrow, direction of flight, grid location of the tail
of the arrow (grid system explained in par. 68) and the
target number will be told.
d. Sequence of telling. — In order that the filter board
plotter will know that he is receiving a plot from radar
teller, the radar teller will first say, "Radio overlap," and
state —
(1) Color of arrow.
(2) Grid location.
(3) Direction of flight.
(4) Last target number, if known.
Example: Radio overlap, red, 72 Klaxen 31, west 6.
■ 92. Radar Board Tellers to Interceptor Board. — a. Gen-
eral. — For each interceptor board, there is, at the radar board,
one radar board teller available, who is connected directly by
telephone with the intercept board plotter.
b. Telephone equipment. — The teller's telephone equip-
ment consists of a one-way lever key and telephone headset.
When the position is occupied, the lever key is operated. No
further action is necessary to answer or originate calls.
c. Information to be told to intercept board plotter. — The
intercept board will notify the teller of a particular target
number that he wants followed. The teller tells information
concerning each new plot of the target appearing on the
radar board. This will include the color of the arrow, grid
location of the tail of the arrow, and direction of flight.
d. Sequence of telling to intercept board plotter.
Target number.
Color of arrow.
Grid location.
Direction of flight.
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93 SIGNAL CORPS FIELD MANUAL
■ 93. Operations of Patching Switchboard. — a. General. —
The training and patching switchboard is used by the wire
chief to make normal connections, to make emergency con-
nections in the case of failures in equipment, to make connec-
tions for training purposes, and for use in handling calls
under emergency conditions.
b. Telephone equipment for patching switchboard. — Pri-
vate lines and toll lines terminate at the training and patch-
ing cord switchboard, and from there are connected to posi-
tions at the Alter board or information center. The opera-
tion of this equipment is as follows :
(1) For normal operation. — For lines which have four jacks
(regular, training, answering, and transfer) connect the two
upper jacks (regular and training) with a patching cord, and
insert a dummy plug in the lowest (transfer) jack. For lines
which have three jacks (alternate, regular, and training)
connect the two lower jacks (regular and training) with a
patching cord. For lines which have two jacks (regular and
training) connect the two jacks with a patching cord.
(2) For emergency in case of failure of circuits. — For lines
which have a particular alternate circuit specifically assigned
(those having three jacks) , connect the upper (alternate)
jack and the lower (training) jack with a patching cord. For
lines which do not have a particular alternate circuit specif-
ically assigned (those having two jacks) , connect the lower
(training) jack to the jack of one of the miscellaneous alter-
nate circuits (those having one jack) with a patching cord.
For the private line circuits (those having four jacks) , no
alternate circuits are provided.
(3) For training, switchboard patching. — When it is de-
sired to train an attendant at a certain position, select the
proper circuit, disconnect the lower end of the patching cord,
and insert the front cord of a P. B. X. cord pair in the same
jack (training) . Then connect the other cord of that pair
to the P. B. X. station of the instructor.
(4) Patching for handling calls, patching switchboard. —
When a position at which a private line circuit is normally
answered is vacated, the dummy plug may be removed from
the lowest (transfer) jack, and any incoming calls will then
light the associated answering lamp. They may be answered
by connecting a front cord to the second jack from the
70
AIRCRAFT WARNING SERVICE 93-94
bottom (answering). It is also possible to ring on a private
line, if necessary, by removing the dummy plug and connect-
ing a back cord for about 1 second. Occasional calls received
over the other types of lines will light the associated lamp,
and may be answered with a front cord.
■ 94. Administrative P. B. X. Operation. — a. General. — On all
calls other than those from extension to extension, the
operator must ask if the call is personal or official. Use the
phrase, "Is this an official call?" If the call is not official,
tell the extension user to make his call from a public tele-
phone booth. On all official calls, other than extension to
extension, request the name of the extension user, and write
on a ticket the extension number, name of the calling person,
and the number called. In all cases, the operator must com-
plete the connection. Do not let the extension user himself
pass his call to the commercial central office operator.
b. Operation of telephone equipment, P. B. X. operation. —
(1) To answer an extension, plug in with a cord in back
row (farther from operator) . To answer a central office line
(called trunk) , plug in with a cord in front row (nearer
operator) . To listen or talk, push back the front key in
line with the cord pair used. To establish connection to an
extension, plus into the called line with the other cord of
pair to answer, then ring on that cord. To ring on the front
cord, pull forward the front key in line with the cord pair
used. To ring on the back cord, pull forward the back key
in line with the cord pair used.
(2) To establish a connection to the dial central office,
have a front key pushed back, plug into the trunk, and when
you hear the dial tone, restore the key. To establish a con-
nection to a manual central office, plug into an idle trunk
with the front cord of the pair used; to answer, have the
front key pushed back, and when the operator answers, give
the operator the number, then restore the front key.
(3) When transferring a central office connection from
one extension to another, have the associated front key
pushed back to avoid losing connection with the central
office. When back and front cord lamps of a pair are both
lighted, take down the associated cords. In a dial office,
restore the back key to normal if operated. If the back or
front cord lamp lights or flashes after it has gone out on
71
94-96 SIGNAL CORPS FIELD MANUAL
answer, push back the associated front key and speak, then
proceed as requested. If no response is received, take down
the associated cord or cords.
(4) When the switchboard is unattended, turn key marked
BATTERY to OFF position.
(5) To ring with the hand generator, turn the key marked
BATTERY to OFF position, turn the crank while holding
the proper front or back in ringing position. Use the hand
generator only when normal ringing current is not available.
Section II
DUTIES OF INFORMATION AND FILTER CENTER
PERSONNEL
■ 95. General. — The personnel who have tactical functions
in an information center are located on a control platform
and in the intercept room. This section describes the tactical
functions which are carried on within an information cen-
ter. Some of these functions may be decentralized to filter
centers, but the functional procedure remains the same.
■ 96. Raid Clerk. — a. General. — The raid clerk is located at
a desk on the floor of the operations room. He will have one
or more helpers or clerks. He has two primary functions:
first, he assigns a raid number to each new raid that appears
in the region, and keeps a raid number assignment sheet (see
Form No. 6, appendix) ; second, the raid clerk is in charge
of the process (for the controller) of identification of the
origin of the raid in question.
b. Telephone equipment. — The raid clerk is provided with
the following telephone equipment at his desk: a cabinet with
keys, and a handset and buzzer for communication with the
controller, radar officer, antiaircraft artillery officer, support
command liaison, bomber command liaison, Navy liaison,
Army liaison, and Civil Aeronautics Administration liaison.
To answer an incoming call when the answering (white) lamp
lights and the buzzer sounds, operate the key associated with
the lighted lamp to the talking (first) position and lift the
receiver. To originate a call, lift the receiver and operate
the key associated with the desired line (as indicated on the
designation strip) to the talking (first) position. To dis-
72
AIRCRAFT WARNING SERVICE 96
connect, restore the key to normal and restore the receiver.
Two or more lines may be bridged together for a conference
on incoming or outgoing calls by operating the key of each
such line to the talking position. There is also a six-button
key and handset for communication with plane position plot-
ters at the intercept boards. To listen in on a line, depress
the associated key and lift the receiver. No answering lamps
are provided, since these lines are used for outgoing calls
only. No facilities are provided for ringing on these lines,
since they are generally in constant use. Should it be neces-
sary to ring, the raid clerk may request the radar operator to
ring on the desired line. There is also a six-button key set
with lamps, a handset, and a buzzer for talking with the con-
troller, administrative P. B. X., and floor supervisors at opera-
tions and filter boards. To answer an incoming call when
the answering lamp lights and buzzer sounds, depress the key
associated with the lighted lamp and lift the receiver. In-
coming calls from the administrative P. B. X. are indicated
by the telephone bell, and are answered by depressing the
key associated with the P. B. X line and lifting the receiver.
To originate a call, depress the key associated with the de-
sired line and lift the receiver. To disconnect, restore the
receiver.
c. Other equipment. — The following additional equipment
is used:
(1) A red colored spotlight to indicate on operations and
radar boards from the raid clerk's position.
(2) Raid log notebook.
(3) Raid number box, containing one set of red plastics,
one set of green plastics numbered from 1 to 99, and a set
of yellow plastics, 10 each of B, X, O, R, N, and T.
d. Duties of raid clerk. — (1) The raid clerk will maintain
a constant watch of the operations board. When a new
flight appears on either the operations board or the radar
board, a target number is assigned to it. This number can-
not be a duplication of any other raid number that may be
on the boards. The clerk either places the raid number on
the stand himself, or by phone directs that the correct num-
ber be placed on the stand by the plotter. If flight is defi-
nitely identified as friendly, and traffic is heavy on the board,
friendly flights over land need not be assigned a target
73
96 SIGNAL CORPS FIELD MANUAL
number. All radar flights will be numbered. The assign-
ment of target numbers under the above option will be at
the discretion of the controller.
(2) When a target comes on the board from any adjoining
region, a blue clip will be fixed to the top of the red or green
(enemy or friendly) card. The raid number will be the one
that was assigned by the other region. As soon as it is
established that this raid will remain in the raid clerk's
region, and that the controller wishes that the target be
plotted, the raid clerk will remove the target number and
blue clip of the other region, assign a free number belonging
to his region, and make a note showing the other region
number in the target assignment list. If the number of the
target assigned in the other region is free in the region in
question, that number should be left on the target, and the
correct entry made on the target number sheet.
(3) When a new target appears on the board, and after
the target number has been assigned, the identity of the
target must be determined. This determination is of pri-
mary importance to the controller, and may or may not be
a difficult problem. This problem will be solved by the fol-
lowing general method: First, upon the order of the con-
troller, or in the absence of the order, the raid clerk will
establish a conference circuit between the pursuit officer, the
Navy, Army, bomber, and Civil Aeronautics Administration
liaison officers, and the radar officer. The controller may or
may not join this conference. When the conference is es-
tablished, the raid clerk advises the conference members of
the new target and requests each member to claim the target,
if the aircraft of the target indicated belongs to his command.
If none of the above officers is able to claim the target, it is
then assumed to be enemy and is so marked. Prior to this
process, the type of aircraft in the flight is indicated by the
yellow type card (IX, IB, IR, or IN) if the type of aircraft
has been reported or deduced. The "I" in front of the type
designation letter indicates that the report has not been
verified. When, and if the type of aircraft is definitely deter-
mined, the "I" card is removed, and a one-letter yellow card
is placed on the stand. This card indicates that the origin
of the target has been absolutely established as belonging to
the command designated by the card. It is seen from the
74
AIRCRAFT WARNING SERVICE 96-97
above that the decisions made by the raid clerk are of very
great importance to the successful carrying out of the mission
of the Air Warning Service, and, therefore, the best type of
personnel must be assigned as raid clerks.
(4) When the raid clerk assigns a target number, indicates
the type of aircraft, or makes any change on the target dis-
play stand, he will call the floor supervisor of the filter
board on which the raid appears, and advise him of the above
changes in order that the filter board may correctly label
the raid in question. A "U" designator card will be placed
on the top of any stand for which the identity of the raid
is in doubt. This does not change the use of the red enemy
card.
■ 97. Controller. — a. Authority. — The controller is the rep-
resentative of the interceptor commander, and he is the tac-
tical commander of the region during his tour of duty. The
forces under his command are composed of assigned or at-
tached intercept pursuit aviation, antiaircraft artillery,
searchlights, automatic weapons, and barrage balloons. The
controller also exercises tactical control of the operation of
all other antiaircraft units that may be in the region other
than those assigned to army corps actually in contact with
the enemy. He also exercises tactical control of all parts
of the Aircraft Warning Service. The controller's staff con-
sists of the personnel on the control platform of the informa-
tion center and the regional signal officer. The duties per-
formed for the controller by members of this staff will be
described in paragraphs 98 to 111, inclusive, for each officer.
b. Location of controller. — The controller is located at the
center of the platform (see fig. 13) overlooking the operations
room. In front and to one side of the controller's position is
mounted a telephone switchboard which permits the con-
troller to get telephone communication to all necessary
locations in his region, as well as the necessary positions in
the information center. It is possible for the controller and
the pursuit officer to reach the following places or persons
through his telephone switchboard:
(1) All control airdromes in the region.
(2) All intercept officers.
75
97 SIGNAL CORPS FIELD MANUAL
(3) All control personnel on the platform.
(4) Raid clerk.
(5) Status board..
(6) Floor supervisor in the operations room.
(7) Floor supervisor in the filter room.
(8) Controllers in adjacent regions.
(9) Other filter rooms in the region.
(10) Administrative P. B. X. board.
(11) Any radio station in the region and to go on the air
over these stations,
(12) Message center chief.
(13) Weather officer.
(14) Interceptor commander. (This line is not to be used
except in the case of emergency.)
(15) The controller is also able to have a conference circuit
set up for him by any liaison officer, which will allow any
or all of the following people to confer: controller, pursuit
officer, bomber, Navy, Army, Civil Aeronautics Administra-
tion, raid clerk, and the radar officer. This conference circuit
is normally used in the process of identifying tracks on the
board in order to determine whether they are friend or
enemy, and if friendly to which command they belong.
c. Controller's switchboards. — The controller's switchboards
are operated in the following manner:
(1) Handset and key equipment. — This equipment is lo-
cated in front of the position, and connects to other informa-
tion and filter centers and to other positions. To answer an
incoming call, when the buzzer sounds, operate the key in the
same vertical row as the light toward the lighted lamp and
lift the receiver. When desired, the buzzer may be made
inoperative by turning the buzzer control key in the upper
right-hand corner to the OFF position. To originate a call
operate the key toward the desired line as indicated on the
designation strip and lift the receiver. Ring by operating
the extreme right-hand lever key (white) downward for about
1 second. When a line which has a colored designation strip
is to be used, do not ring; throw the key and talk. If no
answer is received, then use the ringing key to summon
the operator to "answer" position. To disconnect, restore
the key to normal and restore the handset. To have a con-
ference with bomber, Navy, Army, Civil Aeronautics Admin-
76
AIRCRAFT WARNING SERVICE 97
istration, radar officer, and raid clerk, call any one of these
and have him set up conference on his equipment. In some
cases, the busy (green) lamps will be operative. If the line
is in use, a green lamp will be lighted. The hold position
of the extreme right-hand key (white) is ineffective, and one
call cannot be held while the telephone set is connected to
another call. When the battery key in the lower right-
hand corner is turned to the ON position, all incoming calls
are indicated by a steady lamp and buzzer (if connected).
When turned to the OFF position, the signals are the same
except that on incoming calls over the private line circuits,
the lamp and buzzer will operate only during ringing from the
distant end.
(2) Handset with push-to-talk key, and radio channel
assignment and busy lamps for circuits to radio switch-
board. — Connection to a particular radio channel is re-
quested ,of the radio officer, either over a separate telephone
line as described above, or by direct request, if located nearby.
When the radio officer assigns the channel, the assignment
lamp associated with that channel will light. The push-to-
talk key on the handset switches the radio circuit from re-
ceiving to transmitting, and must be held depressed while
transmitting. While the circuit is in the transmitting con-
dition, the busy lamp associated with that channel will be
lighted. Any other station desiring to transmit on the same
channel at the same time should be governed by the action
of the busy lamp.
(3) Handset to administrative P. B. X. — The handset to
administrative P. B. X. operates as a regular telephone
through the P. B. X. board. The location of the handset,
key equipment, and buzzer to control airdromes, radio A offi-
cer, and pursuit interception officer is to one side of the
controller's position. To answer an incoming call, the an-
swering (white) lamp lights and the buzzer sounds, operate
the key associated with the lighted lamp to the talking
(first) position and lift the receiver. To originate a call, lift
the receiver and operate the key associated with the desired
line (as indicated on the designation strip) to the talking
(first) position. It is necessary to ring only if there is no
answer to the call. To ring, hold the associated key in the
ring (second) position for about 1 second. To disconnect,
11
97-98 SIGNAL CORPS FIELD MANUAL
restore the key to normal and restore the handset. Simul-
taneous communications may be established to one control
airdrome, one pursuit intercept officer, and the radio A officer
by operating these three keys. Two control airdromes or two
pursuit intercept officers should not be connected simul-
taneously.
■ 98. General Mission Assigned to Controller. — a. The gen-
eral mission assigned to a controller is the defense of a
given air space (that space over his region) against enemy
aircraft. The combat effectiveness of the active defense
weapons in air defense is a function of the timeliness, accu-
racy, completeness, and continuity of intelligence of enemy
air movements. This information comes from the Aircraft
Warning Service, and is presented to the controller as a
picture on the operations board. The regional signal officer
is charged with the operation of this service. The original
tactical disposition of the active defense forces in a region
is made by the interceptor commander based upon the results
of the air defense study and plan for the region in question.
As described above, the controller has all the necessary ele-
ments of information to make his tactical decisions for the
employment of the active forces. He is also provided with
the means of issuing his orders, based upon his decision, to
carry out his mission. The tactical decision is made by the
controller, after a brief estimate of the situation, based on
enemy intelligence supplied by the Aircraft Warning Service,
and other G— 2 information of the enemy. This information
is considered in the light of the assigned mission; the relative
combat strength of his own and the enemy forces; the enemy's
capabilities based on his disposition, his strength, type of
aircraft; and the possible targets in the area. The various
plans of action open to the active forces of the air defense
are considered, and the decision is made to use the plan
most likely to succeed in the particular situation presented.
b. The controller, in a region where the Aircraft Warning
Service is secured primarily by radar, must decide the altitude
or amount of vertical interval that pursuit must search for
the target. The amount of vertical interval to be searched
will modify the controller's decision relative to the amount of
pursuit which must be dispatched.
78
AIRCRAFT WARNING SERVICE 99-100
■ 99. PtTRSini Officer. — The pursuit officer is the assistant
controller; he is seeond in command, tactically, of the region.
This officer is supplied with a duplicate of the controller's tele-
phone switchboard. (See par. 97.) The pursuit officer will
be able to perform all the functions of the controller. In
addition to the above, when the pursuit officer is functioning
as pursuit officer, he is directly charged with the following
duties :
a. He keeps himself continually informed as to the status
of all the active forces in the region.
b. He chooses the unit or units from an airdrome to be
ordered on the mission, after being directed to do so by the
controller. That is, the controller may say to the pursuit
officer, "Intercept target five from Suffolk with two flights."
The pursuit officer then chooses the two flights for the mis-
sion. The choice of the correct flights will be based on avail-
ability, readiness, the number of missions already performed,
and by the state of training of the flight commanders in the
light of the mission to be performed.
c. He is charged with making sure that the status board
is correct and kept up to date.
d. If, when a mission is decided upon, it is necessary
immediately to order the intercepting force into the air, the
pursuit officer will, before assigning the mission to an inter-
cept board, order the unit to take off, give the direction in
which the unit is to fly, and the altitude to be gained. When
this is done, he chooses an available intercept board and gives
the mission to the intercept officer at that board. The pur-
suit officer also calls the radio A officer, advises him of the
mission that is starting, and orders that the necessary air-
ground radio channels be set up for the use of the intercept
officer. The pursuit officer also controls the state of status
of the units at airdrome for, or on the order of, the controller.
■ 100. Radio A Officer. — a. Duties. — The radio A officer is
located on the control platform next to the pursuit officer in
a noiseproof cabin. He Is charged with maintaining continu-
ous two-way contact with the intercept forces in flight. He is
provided with a switchboard which allows him to connect the
intercept officers to any of the radio stations in the region.
The radio A officer is in charge of all air-ground radio com-
79
100 SIGNAL CORPS FIELD MANUAL
munication in the region. He will obtain a map of the
region, and on this map will spot the locations of each radio
station. Around these locations, he will indicate the area in
which communication can be had with aircraft from the
radio in question. Knowing this, and by monitoring on the
circuits when in use, he can, by switching to correct station
locations, keep the intercept officer in communication with
the flight or flights which the intercept officer is directing.
b. Telephone channels. — The radio A officer is provided
telephone channels to the following places:
(1) Radio channels.
(2) Intercept officers.
(3) Pursuit officer's and controller's positions.
(4) Clerks at. intercept board.
(5) Controller.
(6) Administration P. B. X.
(7) Miscellaneous lines.
c. Telephone equipment. — The method of operating the
equipment is as follows :
(1) The radio A officer is provided with key cabinet,
desk stand telephone with push-to-talk key, head-band
receiver, and radio-channel busy lamps. The radio chan-
nels terminate in horizontal rows, and stations terminate
in vertical columns. To connect a particular station to a
particular channel,' operate the key which is common to
the row and column concerned. The radio A officer's own
station (desk stand) is associated with the left-hand column.
To answer an incoming call on the radio channel, oper-
ate the left-hand key in the same horizontal row with
the lighted answering lamp. To originate a call on a radio
channel, if the desired channel is idle (no keys operated,
in that horizontal row) , operate the left hand key and
depress push-to-talk key. To disconnect, restore the key.
The push-to-talk key on the desk stand switches the radio
circuit from receiving to transmitting, and must be held de-
pressed while transmitting. While the circuit is in the
transmitting condition, the busy lamp associated with that
channel will be lighted. One or more stations may be con-
nected to a single radio channel, but not more than two
channels should be connected to one station. Any other
station desiring to transmit on the same channel at the same
80
AIRCRAFT WARNING SERVICE 100-101
time should be governed by the action of the busy lamp.
(2) At the radio A officer's position, there is also a button
key set with lamps, handset, and buzzer for communication
with clerks at the intercept board. To answer an incoming
call, when the answering lamp lights and buzzer sounds, de-
press the key associated with the lighted lamp and lift the
receiver. To originate a call, depress the key associated with
the desired line and lift the receiver. To disconnect, restore
the receiver.
(3) The button key set with lamps, handset, and buzzer
for communication with . the controller, administrative
P. B. X., and miscellaneous lines will be used as follows: To
answer an incoming call, when the answering lamp lights
and buzzer sounds, depress the key associated with the lighted
lamp and lift the receiver. Incoming calls from the admin-
istrative P. B. X. are indicated by the telephone bell, and are
answered by depressing the key associated with the P. B. X.
line, and lifting the receiver. To originate a call, depress
the key associated with the desired line and lift the receiver.
To disconnect, restore the receiver. When necessary, the
radio A officer may talk to the remote radio station operator
as follows:
(a) If the radio channel is not in operation, and if the
channel key is depressed, the radio A officer may talk with
the radio operator.
(b) If the radio channel is in operation and on transmit,
the radio A officer may not talk with the operator.
(c) If the radio channel is in operation and on receive, the
radio A officer, in order to talk with the radio operator with-
out going on the air, will rapidly operate the channel key.
This will, by flashing a lamp signal, tell the remote radio
operator to turn the transmitter key off. When this has been
done, the radio A officer will be table to talk with the remote
radio operator without going on the air. The receiver will
still be operative in this condition. The radio A officer at each
regional information center has a 1,000-cycle test oscillator to
be used for testing the quality of the radio-channels lines,
and, when used, allows the radio-station operator to adjust
his line gain control to the correct amount.
■ 101. Radar Officer. — a. The radar officer is located on the
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101 SIGNAL CORPS FIELD MANUAL
control platform to one side of the controller. He is charged
with the tactical operation of all radar equipment. He will
advise the controller on the methods of operation of this
equipment so that the controller can receive the type of
information needed, at the time needed.
b. The radar officer is provided with a telephone switch-
board which gives him telephone connections to the follow-
ing places:
(1) Controller.
(2) Bomber command.
(3) Navy liaison officer.
(4) Army liaison officer.
(5) Civil Aeronautics Administration.
(6) Raid clerk.
(7) Radar plotters.
(8) Radar equipment.
(9) Administrative P. B. X.
c. The radar officers' switchboard is operated as follows:
(1) To answer incoming call, when the answering (white)
lamp lights and buzzer sounds, operate the key associated
with the lighted lamp to talking (first) position and lift the
receiver. To originate a call, lift the receiver and operate the
key associated with the desired line (as indicated on the
designation strip) to the talking (first) position. To dis-
connect, restore the key to normal and restore the receiver.
A conference of two or more lines together may be made, either
on incoming or outgoing calls, by operating the key of each
such line to the talking position.
(2) The radar officer has key equipment, a handset, and
buzzer for communication with the controller, administrative
P. B. X., and radar locations. This equipment is operated in
the following manner: To answer an incoming call, when
the answering (white) lamp lights, and the buzzer sounds,
operate the key in the same vertical row toward the lighted
lamp and lift the receiver. When desired, the buzzer may be
made inoperative by turning the buzzer-control key in the
upper right hand corner to the OFF position. Incoming calls
from the administrative P. B. X. are indicated by the tele-
phone bell, and are answered by operating the key toward the
P. B. X. line as indicated on the designation strip and lifting
the receiver. To originate a call, operate the key in the same
82
AIRCRAFT WARNING SERVICE 101-102
vertical row toward the desired line as indicated on the desig-
nation strip and lift the receiver. To ring on a line, operate
the extreme right-hand lever key (white) downward for
about 1 second. Private lines that are continuously manned
will be indicated in color on the designation strip. Ring
only on these circuits if you receive no answer to a challenge.
In some cases, the busy (green) lamps will be operative. If
so, a green lamp will be lighted while the associated line is in
use either on an incoming or outgoing call. The HOLD posi-
tion of the extreme right-hand key (white) is ineffective,
and one call cannot be held while the telephone set is con-
nected to another call.' When the battery key in the lower
right-hand corner is turned to the ON position, all incoming
calls are indicated by a steady lamp and buzzer (if connected) .
When turned to the OFF position, the signals are the same,
except that on incoming calls over the private line circuits,
the lamp and buzzer will operate only during ringing from
the distant end. The above does not apply to calls from the
administrative P. B. X.
■ 102. Civil Air Raid Officer. — a. The civil air raid officer
will be on duty on the platform overlooking the operations
board at information centers and filter centers. Under this
officer, there is also on duty at all times a switchboard opera-
tor for the special civil air raid warning switchboard.
b. The equipment provided includes a special map known
as the "memory board," a raid warning template, and a tele-
phone. The memory board is a map of the region or filter
area, provided with a translucent surface, so arranged that
colored lights, yellow, blue, red, and white, indicate the state
of raid warning which has been given to each of the raid
control districts into which the area is divided. These lights
are automatically controlled by connections from the civil
air raid warning switchboard. Four degrees of warning are
provided as follows:
(1) Yellow message. — This is a preliminary caution sent
to a district as soon as there is any possibility of a raid in
the district. This is a confidential message intended for
transmission by civil authorities to a limited number of
recipients who take unobstrusive precautionary measures in
order to be ready to act instantly when a blue or red warning
message is received.
83
102 SIGNAL CORPS FIELD MANUAL
(2) Blue message. — This is the second degree of caution
transmitted when the objective of the raiders is determined.
This message usually has the same distribution as the yellow
message, and is also confidential. At night, it is a light
warning for railroads, essential industries, and highway
officials to put cut or dim lights in accordance with pre-
arranged plans for a blackout.
(3) Red message. — This is the action warning sent when
the possibility of a raid becomes imminent. This is a warn-
ing message to the public, and after its receipt at the various
control centers, it is relayed to the public by audible warning
signals such as sirens or power whistles.
(4) White message. — This is the "all clear" message sent
after raiders have either passed from a district or all danger
of a further raid is over for the time being. This message is
sent to all recipients of the other messages, except that it is
not relayed to. the public unless a previous red message is
still in force.
c. It is the duty of the civil air raid officer to determine the
degree of alarm, the control centers to which issued, the
time, and to make certain that the appropriate message
is promptly transmitted to and acknowledged by the chief
warden or controller at each control center.
d. The principal aid to the civil air raid officer in arriving
at his decision is the warning template, which is a trans-
parent guide, to the same scale as his map, with yellow, blue,
and red curves. When superimposed on present position
and course of an enemy air attack, these curves will indicate
probable points which the enemy might be expected to reach
after so many minutes of flight (based, for present purposes,
on 20, 12, and 5 minutes' straight flight at 300 miles per hour
for yellow, blue, and red, respectively) . It should be espe-
cially noted that after the raid has passed, any degree of
warning which has been given is retained until the white
"all clear" signal may safely be given. The progression is
thus from- yellow to blue or white only; from blue, either
to red or to white, never to yellow; and from red only to
white. The template is used as a guide only. Judgment
and experience will indicate a broader basis for the issuance
of warnings.
e. When the civil air raid officer transmits an air raid
84
AIRCRAFT WARNING SERVICE 102-103
warning signal, the local toll operators repeat the orders as
received. The toll operators ring the warden for that dis-
trict, and also light the appropriate colored signal on the
•warden's desk. The civil official acknowledges both verbally
and by pressing a colored button. His acknowledgment is
received in the information center by the switchboard attend-
ant, who then replaces the talking cards with "memory plugs"
in the jacks marked according to the color of warning given.
When either the cord or the memory plug is in any jack on
the switchboard, the corresponding colored light of the civil
air. raid warning map glows.
/. The foregoing procedure is illustrative of that used by
the civil air raid officer at any filter center for raid warnings
within his own filter area. In addition, it is necessary to
provide for warnings in a wide overlap area surrounding
each region. The civil air raid officer at the regional infor-
mation center is charged with this responsibility, covering
initially a belt 100 miles wide surrounding the region. For
any raid over his own region, he will determine the need for
warning control centers in adjacent regions, and will trans-
mit such warnings over lines to be provided to the civil air
raid warden switchboard in the filter center concerned.
■L403-. Antiaircraft Officer. — a. Duties. — The antiaircraft
officer will maintain at all times an accurate up-to-date
record of the location of all antiaircraft artillery, searchlights,
and barrage balloons in the region. He will be prepared
to advise the regional commander concerning any changes
in the above locations necessitated by the situation. The
antiaircraft officer will observe any hostile air activity as
shown on the operations board which might affect the anti-
aircraft artillery, searchlights, or balloon barrage, and will
transmit information of such activity promptly to local
air-defense forces concerned. He will require the antiair-
craft artillery information service to report to him promptly
any enemy information, will analyze such information, and
pass to the controller any data deemed relevant and not
already known to that official. He will transmit to the anti-
aircraft artillery, searchlights, and balloon barrage any
orders of the controller affecting them. When the con-
troller delegates' to him the authority for such action, he
85
103 SIGNAL CORPS FIELD MANUAL
will determine from a study of the situation the advisability
of ordering antiaircraft fire withheld, barrage balloons low-
ered, and searchlights kept out of action, and will issue such
orders.
b. Telephone equipment. — The antiaircraft artillery officer
has telephone connections to the following places or persons:
the administrative P. B. X., the controller, support command,
bomber command, Navy and Army liaison officers, Civil
Aeronautics Administration, and the raid clerk. The anti-
aircraft officer also has telephone communication to the
antiaircraft stations. The telephone equipment is operated
in the following manner:
(1) The antiaircraft officer has a cabinet with key equip-
ment, a handset and buzzer for communication. To answer
an incoming call, when the answering (white) lamp lights
and buzzer sounds, operate the key associated with the lighted
lamp to the talking (first) position and lift the receiver. To
originate a call, lift the receiver and operate the key asso-
ciated with ths desired line (as indicated on the designation
strip) to the talking (first) position. To disconnect, restore
the key to normal and restore the receiver. Two or more
lines may be bridged together for a conference either on in-
coming or outgoing calls, by operating the key of each such
line to the talking position.
(2) Key equipment, lamps, handset, buzzer, and white
beehive lamp for communication with the controller and anti-
aircraft stations. To answer an incoming call, when the
answering (white) lamp lights and the buzzer sounds, oper-
ate the key in the same vertical row toward the lighted lamp
and lift receiver. When desired, the buzzer may be made
inoperative by turning the buzzer control key in the upper
right-hand corner to the OFF position. Incoming calls from
the controller are indicated by lighting of the white beehive
lamp, and are answered by merely lifting the receiver. If
there is an incoming call from the controller while the hand
set is in use on another call, the beehive lamp will not light,
and the controller will immediately be connected. To origi-
nate a call, operate the key in the same vertical row toward
the desired line as indicated on the designation strip and lift
the receiver. Ring by operating the extreme right-hand
(white) lever key downward for about 1 second. The HOLD
86
AIRCRAFT WARNING SERVICE 103-105
position of the extreme right-hand key (white) is ineffective,
and one call cannot be held while the telephone set is con-
nected to another call. When the battery key in the lower
right-hand corner is turned to the ON position, all incoming
calls are indicated by a steady lamp and buzzer (if connected) .
When turned to the OFF position, the signals are the same
except that on incoming calls over the private line circuits,
the lamp and buzzer will operate only during ringing from
the distant end. Handset for communication with the ad-
ministr ative p. B. X. operates as a regular extension.
■ 104. Liaison Officers. — a. Duties. — The liaison officers
are located around the platform in positions which allow
them to see the information with which they are concerned.
These officers represent the Army and air support, the Navy,
the bomber command, and the Civil Aeronautics Authority.
They are charged with supplying the controller with all the
information that the controller may want or need to aid
him in making his decisions relative to the branch repre-
sented by the liaison officer. They also relay to their respec-
tive headquarters or activity all orders, instructions, or sug-
gestions issued by the controller that apply to them. In
addition to the above, one of the most important functions
of these officers is to aid the controller and raid clerk in
identifying the aircraft in any flight that appears on the
board. This identification is made in two main categories,
friendly or enemy. If the flight is friendly, then it must
be determined to what organization the aircraft belong.
In order to do this, each of the above officers must know the
disposition of all the aircraft in the air from his command.
&. Telephone equipment. — The liaison officers are provided
with telephone for communication with the controller, radar
officer, antiaircraft artillery officer, raid clerk, and other
liaison officers. The telephone equipment operates as ex-
plained in paragraph 96b. Check designation strip carefully
before originating call.
■ 105. Weather Officer. — Each region will have a weather
officer located at the information center. Each information
center will have a weather teletypewriter connected to a
weather channel for up-to-date weather. The weather
officer will be charged with making 6-hour forecasts for
87
105-106 SIGNAL CORPS FIELD MANUAL
future weather conditions within his region, and also
charged with supplying the controller with an hourly map
showing the present flying conditions within the region.
This map will be an outline map of the region upon which
the present weather conditions will be plotted with cross
hatching and superimposed letters to indicate type of
weather to be found over the area.
■ 106. Operation of Intercept Board. — a. General. — Around
the intercept board (see fig. 13) are located an intercept offi-
cer, enemy plotter, friendly plotter, and a clerk.
b. Telephone equipment. — The enemy plotter has a six-
button key set with associated lamps, one-way lever key, and
headset for communication with radar tellers and intercept
tellers. To answer an incoming call, when the answering
lamp lights, depress the associated key and operate the lever
key. Use the phrase "Go ahead" when answering. The
friendly plotter has a six-button key set with associated lamps,
one-way lever key, and telephone headset for communication
with plane position tellers at airdromes. Operation of the
equipment is the same as that of the enemy plotter. The
clerk has a six-button key set with associated lamps, telephone
handset, and buzzer for communication with radio A officer,
status plotter, administrative P. B. X., arid intercept teller
or secondary filter board teller. To answer an incoming
call, when the answering lamp lights and buzzer sounds, de-
press the key associated with the lighted lamp and lift the
receiver. Incoming calls from the administrative P. B. X.
are indicated by the telephone bell, and are answered by
depressing the key associated with the P. B. X. line and lifting
the receiver. To originate a call, operate as instructed in
paragraph 96b. The intercept officer has a six-button key
set, one-way lever key, beehive lamp, and handset for com-
munication with the controller, pursuit officer, and the air-
dromes. Normally, the intercept clerk will use this equip-
ment for the intercept officer. To answer incoming calls from
the controller or pursuit officer, when the beehive lamp lights,
lift the receiver. To establish connection to the airdrome,
depress the proper push-button key and then operate the
lever key. To disconnect from the airdrome, restore the
lever key and restore handset.
88
AIRCRAFT WARNING SERVICE 106
c. Duties of the intercept board personnel. — (1) The enemy
plotter will receive the order to plot a given target from the
intercept officer. The intercept officer will designate the
target to be plotted by giving the target number. The plot-
ter will then call the intercept tellers associated with his
board, and order them to tell plotted target information re-
garding the designated enemy target. He then plots on the
intercept map overlay all the information told him about
the target he called for. The plotter will note the time he
receives the first few plots so as to make it possible to make
an early estimation of the enemy's ground speed. These
times will also serve as a time base for checking the ground
speed later in the problem. This plotter will be ready to
predict the enemy's course 15 or 20 minutes ahead of the
latest plot when needed by the intercept officer. The plots
should be made with red, green, and blue pencil to corre-
spond with the color code as told by the teller. Target in-
formation will be noted near the start of the track. (See
par. 70.)
(2) The friendly or pursuit plotter is charged with plotting
the course of the interceptor pursuit force ordered on the
mission assigned to the intercept board in question. This in-
formation is received over telephone lines from the airdrome
in question.
(3) The intercept officer's clerk is located at a small table
near the intercept board. This clerk operates the interceipt
officer's switchboard, takes all calls for the intercept officer
if he is busy, makes a record of all orders transmitted by the
intercept officer, and keeps any other records required by
the intercept officer. The clerk also listens in on all radio
contacts, and makes such notes on the messages received as
desired by the intercept officer. He also transmits to the
status board any changes of status that occur during the
flight. (See par. 42/.)
(4) The intercept officer is in charge of all the men as-
signed to his intercept board. When the intercept officer is
assigned a mission, he is in charge of that flight, subject
only to orders from the controller and pursuit officer. The
controller and pursuit officer will oversee the operations of
the intercept officer, and may take over the flight in question
or change any orders issued by the intercept officer at any
89
106-107 SIGNAL CORPS FIELD MANUAL
time. The intercept officer must at all times have the latest
winds aloft for his area, and must have the temperature
aloft reported to him when needed. The intercept officer
has two primary functions. First, he will plot the course
of any enemy raid or raids assigned to his board, and from
these be prepared to calculate a course for whatever inter-
cept forces are assigned him in such a manner as to place
the intercept force in front of the enemy formation. The
intercept force should arrive at such a point 3 minutes ahead
of the enemy. Second, the intercept officer is charged with
issuing the necessary navigation instructions to the unit in
flight to carry out the above via the provided radio channels.
He will make every effort possible to reduce to a minimum
the length of all radio contacts made. He is also charged
with insuring that all personnel at the intercept board pass
on information pertaining to other activities.
'■"TOT . Status-Board Plotters. — a. The status-board plotters
are charged with keeping the information on the status
board up-to-date and correct in order that the information
on this board will accurately picture the status of the air-
craft and pilots at each operating airdrome in the area.
In order to accomplish the above, the status-board plotter
is given telephone access to the command telephone line
to each airdrome. Over this line he receives the changes in
status from the airport where changes of status occur. Sta-
tus is plotted for the smallest tactical unit stationed at the
airdrome. If any part of the element is not available, the
whole element is out. At present, the status boards are made
up of blackboards which are divided vertically into elements,
and horizontally into the status to be recorded (see fig. 14) .
It is planned to replace these boards with electrical status
boards as soon as possible. When the electrical board is used,
the status is designated by lighting the light in the correct
division of the board. When the blackboard is used, a num-
ber will be entered in the appropriate column of the status
board to indicate the number of aircraft available in each
arrangement. This provision will allow the status board
to operate without change for t\?o-, three-, or four-ship
arrangement. If a unit is not available, there will be a
number in the "not available" column. The unit is reported
90
AIRCRAFT WARNING SERVICE 107
as not available if any part of that unit is unable to under-
take a combat flight due to lack of reserves or necessary
replacements. If an element is reported as available, the
number will be placed in the correct available column, and
also in the column which correctly describes the element's
state of availability; that is, readiness, standby, alert, or sta-
tions. When a unit at the airdrome is ordered off, the status-
board plotter will be informed by the pursuit officer, and
he will mark up the change of status in the correct columns,
and remove all other numbers on the status board for that
unit.
b. When radio contact has been established with the unit
after take-off, the intercept officer's clerk will notify the
status-board plotter of this fact, and also of the type of
mission. This information is then marked up and the "or-
dered off" removed. When the unit in question sights the
enemy, the intercept clerk will notify the status-board plot-
ter, and it will be so marked up. The "fuel remaining section"
will be maintained by the status teller based upon a time
schedule provided for each type of aircraft by the pursuit
officer. In order to do this the status teller will note the time
of each take-off, and fill in the fuel column after the correct
amount of time has passed. The "returning to land column"
will be filled in on notification of this fact from the intercept
clerk. The "servicing" column is filled in on information from
the airdrome. (See par. 42/.)
c. The status plotter has key equipment, two-way lever,
and telephone headset for communication with plane-posi-
tion tellers at airdromes, and airdrome command and status
lines. To occupy position, connect headset and operate lever
key. To answer an incoming call, when the answering (white)
lamp lights, operate the key in the same vertical row toward
the lighted lamp. To originate a call, operate the key in the
same vertical row toward the desired line as indicated on the
designation strip. Ring by operating the extreme right-hand
lever key (white) downward. As an alternative, the desig-
nation strip may be colored to indicate the private line cir-
cuits, and the ringing key employed only with such lines.
The HOLD position of the extreme right-hand key (white) is
ineffective, and one call cannot be held while the telephone
set is connected to another call. When the battery key in the
91
107 SIGNAL CORPS FIELD MANUAL
lower right-hand corner is turned to the ON position, all in-
coming calls are indicated by a steady lamp and buzzer (if
connected) . When turned to the OPP position, the signals
are the same except that on incoming calls over the private
line circuits, the lamp and buzzer will operate only during
ringing from a distant end. The status plotter has push-
button keys and designation strip, if lines also appear at the
controller and pursuit officer's equipment, for communication
with the controller and pursuit officer. To signal the con-
troller, operate the push-button key associated with the line
over which the request was received. The status plotter has
push-button keys with lamp, headset, and buzzer for com-
munication with intercept officer. To answer an incoming
call, when the answering lamp lights and buzzer sounds, de-
press the key associated with the lighted lamp and lift re-
ceiver. To originate a call, depress the key associated with
the desired line and lift the receiver. To disconnect, restore
the receiver. The status plotter also has a handset connected
to the administrative P. B. X. All incoming calls from air-
dromes will be answered by the status plotter. If the call is
for the controller, the plotter will call the controller and notify
him of the call.
d. The status teller when located at a filter center will tell
all information appearing on the board to the "plotter at the
information center status board. The tellers located on the
status board at information centers who tell to the status
board at the intercepter command (command post) will tell
only information concerning the following status available,
readiness, standby, alert, and on mission. The status board
at the command post will have only the above status listed,
and only one column per squadron. Status will be entered
in units of one flight (two elements) , and will be marked up
as 1, 2, or 3, meaning first, second, or third flights of the
squadron are in the status listed.
e. The status teller has a one-way lever key, lamp, single
push-button ringing key, and telephone headset. To occupy
position, connect the headset, and operate the lever key. To
answer a call, no further action is required if the lever key
is kept in the operated position. Incoming calls are indi-
cated by a lighted lamp and a monotone heard in the re-
92
AIRCRAFT WARNING SERVICE 107-111
ceiver. To originate a call, depress push-button key for about
1 second.
■ 108. Rescue Officer. — a. The rescue officer will have tele-
phone communication to the controller, Navy, pursuit offi-
cer, radio A officer, all intercept boards, all Army Air Forces
posts, crash boat houses, and docks.
6. The duties of the rescue officer are to observe raids so
that, if over water, crash boats and rescue boats may be dis-
patched to the vicinity of the air battle, and to coordinate
the rescue activities with the necessary authorities, both civil
and military.
■ 109. Regional Signal Officer. — The regional signal officer
is a staff officer of the regional commander. He is respon-
sible for all plotting operations and administration of the
information center. He is responsible for the operation of
all communication within the region, except the organic
communication of pursuit aviation and antiaircraft artillery.
■ 110. Bomber Command Leaison Officer. — This officer is
located on the platform or balcony. This officer's duties are
to identify all bombardment flights in the area, and to supply
to his commander any other information needed from the
interceptor headquarters.
■ 111. Federal Communications Commission Liaison Offi-
cer. — This officer will have direct communication with a con-
trolling point for all civilian radio stations in the region,
and will be able to close them down at any time necessary
to prevent the use of the carrier beam as a "homing" aid by
the enemy. This officer will also aid in setting up emergency
communications in case of failures at any time.
93
SIGNAL CORPS FIELD MANUAL
Appendix
MODEL FORMS
■ 1. Form No. 1 (Flash Message Form) . — Call your telephone
central and say, "Army flash " (give your phone num-
ber). Central will connect you with an Army information
center. When you hear, "Army, go ahead, please," you say,
"Flash," and continue message you have checked on form be-
low, in the order indicated.
94
AIRCRAFT WARNING SERVICE
•o
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95
SIGNAL CORPS FIELD MANUAL
■ 2. Form No. 2 (Report of Observation Post Organizers) . —
a. Please fill in this form and mark exact location of obser-
vation post on section of map attached. Return two copies
of this form with marked map to regional commander in the
franked enevelope provided; no postage is required.
b. The telephone subscriber listed below has volunteered
to permit the use of the telephone at the observation post
selected, for the reporting of Government collect flash mes-
sages. This telephone will be available to authorized ob-
servers continuously, day and night, during periods of opera-
tion of the Aircraft Warning Service.
(Name of subscriber) (Exchange and telephone number)
(Address)
(1) State location of telephone in the house, that is, in the
living room, kitchen, bedroom, etc.
(2) State location of observation post in reference to the
house, that is, in the yard, atop the house, on a hill, etc.
(3) How long, in seconds, does it require to reach the tele-
phone from the observation post?
c. The person whose name appears below has volunteered
to act as chief observer for the observation post covered by
this report; has been furnished a copy of instructions for
chief observers; and agrees to make every effort to comply
with the provisions of those instructions:
(Chief observer's name) (Telephone number)
(Address)
d. The persons whose names appear below have volun-
teered to act as assistant chief observers; to assist the chief
observer In carrying out the provisions of instructions for
96
AIRCRAFT WARNING SERVICE
chief observers; and to assume the duties of chief observer
in the event that the chief observer is unable to act.
(1st asst chief observer) (Telephone, if any)
(Address)
(2d asst chief observer) . (Telephone, if any)
(Address)
(Name of person making report) (Telephone, if any)
(Address)
■ 3. Form No. 3 (Instructions for Chief Observers') . — a.
Duties. — The chief observer is responsible for —
(1) Selection of observers. — Observers may be either male
or female. In many cases, female observers will be more
readily available than suitable male observers. Male ob-
servers should, if practicable, be over 35 or under 18 years of
age, and should be chosen from those who are not expected to
be called to military service. All observers must be able to
speak English clearly and distinctly, so that they can tele-
phone flash messages without difficulty or misunderstanding.
All observers selected should have good eyesight for detection
of airplanes. It has been learned that blind persons are well
adapted to assist observers because of their well-developed
hearing and sensing faculties. Many societies for the blind
have appealed to the air defense commander to afford such
opportunities for service. It is hoped than an opportunity to
serve will be accorded to the blind who live near the observa-
tion post.
(2) Continuous manning of observation post. — The chief
observer should obtain enough observers to man the observa-
tion post continuously during any period of active air opera-
tions without undue hardship on any individual : This can be
done by arranging watches or shifts with a definite period of
observation duty for each observer. It is also advisable to
secure one or more alternate or emergency observers who are
97
SIGNAL CORPS FIELD MANUAL
not assigned a watch, but who are available to serve in place
ol any observer Who cannot stand the scheduled watch. The
exact length of each watch, the number of watches, the num-
ber of observers on each watch, and the total number of ob-
servers can be determined only by each chief observer, who is
thoroughly familiar with local conditions. In general, a 2-
or 3-hour watch is considered reasonable for the period be-
tween 10:00 PM and 6:00 AM, and a 4- to 6-hour watch lor
other periods.
(3) Instruction of observers. — Each observer should be fully
familiar with instructions for observers and with the' flash
message form, before engaging in observation duty. The chief
observer should test each observer to insure a complete under-
standing of the procedure of telephoning flash messages and
using the flash message form. By acting as the telephone
control operator and then as the operator at Army informa-
tion center, the chief observer may examine each observer and
insure complete understanding of the correct form and pro-
cedure. This should be done before the observer goes on any
observation duty.
(4) Supervision of operations at observation post. — It is
not necessary that a chief or assistant chief observer remain
at the observation post throughout the hours of scheduled
air operations. The chief observer is responsible for all opera-
tions pertaining to the Aircraft "Warning Service at the ob-
servation post, and should visit the observation post often
enough to see that all is well.
(5) Records. — At the observation post should be kept the
chief observer's folder in which are filed the following records :
Duplicate copy of Form No. 2 (Report of Observation
Post Organizers).
Duplicate copy of Form No. 4 (Report of Chief Ob-
servers) .
Several War Department penalty envelopes.
At least one copy of Form No. 3 (Instructions for Chief
Observers) .
At least one copy of Form No. 5 (Instructions for Ob-
servers) .
A complete list of observers and how they can be
reached.
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AIRCRAFT WARNING SERVICE
(6) Initial report of chief observer. — The chief observer
should complete Form No. 4 and mail that report as soon as
possible in one of the War Department penalty envelopes pro-
vided to the regional commander. Postage stamps are not
required on these envelopes.
b. Procedure. — (1) An Aircraft Warning Service is an es-
sential part of air defense. Prom the timely and accurate
reporting of the volunteer observer corps, it will be possible
for our pursuit aviation to locate and intercept enemy air-
craft. The observer service offers an opportunity for those
who cannot actively participate in military operations to do
important work for the national defense.
(2) Each observation post should be organized with per-
sonnel drawn from the immediate vicinity in order that there
will be a minimum of personal inconvenience and no personal
expense incurred. The flash messages used in reporting
airplanes will be charged to the Federal Government as
Government collect telephone calls. There are no funds
available for special equipment or facilities or for services.
For the initial organization and operation, the air defense
requirements must be met by the patriotic volunteers who
can provide their telephones, premises, and services to this
essential Aircraft Warning Service.
(3) The proc
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