Federal Register/Vol. 81, No. 85 / Tuesday, May 3, 2016 / Proposed Rules 26487
Federal Register/Vol. 81, No. 85 / Tuesday, May 3, 2016 / Proposed Rules 26487
The Proposed Amendment
Accordingly, under the authority
delegated to me by the Administrator,
the FAA proposes to amend 14 CFR part
39 as follows:
PART 39—AIRWORTHINESS
DIRECTIVES
■ 1. The authority citation for part 39
continues to read as follows:
Authority: 49 U.S.0 106(g), 40113. 44701.
§39.13 [Amended]
■ 2. The FAA amends § 39.13 by adding
the following new airworthiness
directive (AD):
The Boeing Company: Docket No. FAA-
2016-6139: Directorate Identifier 2015-
NM-061-AD.
(a) Comments Due Date
Wo must receive comments by June 17.
2016.
(b) Affected ADs
None.
(c) Applicability
This AD applies to Tho Booing Company
Model 737-600. -700. -700C. -800. -900.
and -900ER series airplanes. certificated in
any category. excluding airplanes equipped
with a flammability reduction means (FRM)
approved by the FAA as compliant with the
Fuel Tank Flammability Reduction (FTFR)
rule (73 FR 42444, July 21. 2008)
requirements of section 25.981(b) or section
26.33(c)(1) of the Federal Aviation
Regulations (14 CFR 25.981(b) or 14 CFR
26.33(c)(1)).
(d) Subject
Air Transport Association (ATA) of
America Code 28. Fuel.
(e) Unsafe Condition
This AD was prompted by fuel system
reviews conducted by the manufacturer. We
are issuing this AD to prevent ignition
sources inside the center fuel tank. which. in
combination with flammable fuel vapors.
could result in a fuel tank explosion and
consequent loss of the airplane.
(I) Compliance
Comply with this AD within the
compliance times specified. unless already
done.
(g) Modification
Within 60 months after the effective date
of this AD. modify the fuel quantity
indicating system (PQIS) to prevent
development of an ignition source inside the
center fuel tank due to electrical fault
conditions, using a method approved in
accordance with the procedures specified in
paragraph (i) of this AD.
(h) Alternative Actions for Cargo Airplanes
For airplanes used exclusively for cargo
operations: As an alternative to the
requirements of paragraph (g) of this AD. do
the actions specified in paragraphs (h)(1) and (h)(2) of this AD. using methods approved in
accordance with the procedures specified in
paragraph (i) of this AD. To exercise this
alternative, operators must perform the first
inspection required under paragraph (h)(1) of
this AD within 6 months after the effective
date of this AD. To exercise this alternative
for airplanes returned to service after
conversion of the airplane from a passenger
configuration to an all-cargo configuration
mom than 6 months after the effective date
of this AD. operators must perform the first
inspection required under paragraph (h)(1) of
this AD prior to further flight after the
conversion.
(1) Within 6 months after the effective date
of this AD. record the existing fault codes
stored in the FQIS processor and then do a
BITE check (check of built-in test equipment)
of the PQIS. If any nondispatchable fault
code is recorded prior to the BITE check or
as a result of the BITE check. before further
flight. do all applicable repairs and repeat the
BITE check until a successful test is
performed with no nondispatchable faults
found. using a method approved in
accordance with the procedures specified in
paragraph (i) of this AD. Repeat these actions
thereafter at intervals not to exceed 650 flight
hours. Modification as specified in paragraph
(h)(2) of this AD does not terminate the
repetitive BITE check requirement of this
paragraph.
(2) Within 60 months after the effective
date of this AD. modify the airplane by
separating FQIS wiring that runs between the
FQIS processor and the center tank wing spar
penetrations. including any circuits that
might pass through a main fuel tank. from
other airplane wiring that is not intrinsically
safe. using methods approved in accordance
with the procedures specified in paragraph
(i) of this AD.
(i) Alternative Methods of Compliance
(AMOCs)
(1) The Manager. Seattle Aircraft
Certification Office (ACO). FAA. has the
authority to approve AMOCs for this AD. if
requested using the procedures found in 14
CFR 39.19. In accordance with 14 CPR 39.19.
send your request to your principal inspector
or local Flight Standards District Office. as
appropriate. If sending information directly
to the manager of the ACO. send it to the
attention of the person identified in
paragraph (j) of this AD. Information may be
emailed to: 9-AM41-Seattle-ACO-AMOC-
Requests€faa.gov.
(2) Before using any approved AMOC.
notify your appropriate principal inspector.
or lacking a principal inspector, the manager
of the local flight standards district office/
certificate holding district office.
(3) An AMOC that provides an acceptable
level of safety may be used for any repair.
modification. or alteration required by this
AD if it is approved by the Boeing
Commercial Airplanes Organization
Designation Authorization (ODA) that has
been authorized by the Manager. Seattle
ACO. to make those findings. To be
approved. the repair method. modification
deviation, or alteration deviation must meet
the certification basis of the airplane. and the
approval must specifically refer to this AD. (j) Related Information
For more information about this AD.
contact Jon Regimbal. Aerospace Engineer,
Propulsion Branch. ANM-140S. FAA. Seattle
Aircraft Certification Office (ACO). 1601 Lind
Avenue SW., Renton, WA 98057-3356;
phone: 425-917-6506: fax: 425-917-6590:
email: fon.Regimbalefaa.gov.
Issued in Renton. Washington. on April 15.
2016.
Victor Wicklund,
Acting Manager, Transport Airplane
Directorate, Aircraft Certification Service.
[FR Doc. 2016-09799 Flied 5-2-16:8:45 aml
BILLING CODE 4910-13-P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2016-6144; Directorate
Identifier 2015-NM-088-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus
Airplanes
AGENCY: Federal Aviation
Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking
(NPRM).
SUMMARY: We propose to adopt a new
airworthiness directive (AD) for certain
Airbus Model A318, A319, and A320
series airplanes; Model A330-200, —200
Freighter, and —300 series airplanes; and
Model A340-200, —300, —500, and —600
series airplanes. This proposed AD was
prompted by fuel system reviews
conducted by the manufacturer. This
proposed AD would require modifying
the fuel quantity indicating system
(FQIS) to prevent development of an
ignition source inside the center fuel
tank due to electrical fault conditions.
This proposed AD would also provide
alternative actions for cargo airplanes.
We are proposing this AD to prevent
ignition sources inside the center fuel
tank, which, in combination with
flammable fuel vapors, could result in a
fuel tank explosion and consequent loss
of the airplane.
DATES: We must receive comments on
this proposed AD by June 17, 2016.
ADDRESSES: You may send comments,
using the procedures found in 14 CFR
11.43 and 11.45, by any of the following
methods:
• Federal eRulemaking Portal: Go to
http://www.regulations.gov. Follow the
instructions for submitting comments.
• Fax:202-493-2251.
• Mail: U.S. Department of
Transportation, Docket Operations, M—
EFTA00792635
26488 Federal Register / Vol. 81, No. 85 / Tuesday, May 3, 2016 / Proposed Rules
30, West Building Ground Floor, Room
W12-140,1200 New Jersey Avenue SE.,
Washington, DC 20590.
• Hand Delivery: Deliver to Mail
address above between 9 a.m. and 5
p.m., Monday through Friday, except
Federal holidays.
Examining the AD Docket
You may examine the AD docket on
the Internet at http://
www.regulations.gov by searching for
and locating Docket No. FAA-2016-
6144; or in person at the Docket
Management Facility between 9 a.m.
and 5 p.m., Monday through Friday,
except Federal holidays. The AD docket
contains this proposed AD, the
regulatory evaluation, any comments
received, and other information. The
street address for the Docket Office
(phone: 800-647—5527) is in the
ADDRESSES section. Comments will be
available in the AD docket shortly after
receipt.
FOR FURTHER INFORMATION CONTACT: Dan
Rodina, Aerospace Engineer,
International Branch, ANM-116,
Transport Airplane Directorate, FAA,
1601 Lind Avenue SW., Renton, WA
98057-3356; telephone 425-227-2125;
fax 425-227-1149.
SUPPLEMENTARY MFORMA710N:
Comments Invited
We invite you to send any written
relevant data, views, or arguments about
this proposal. Send your comments to
an address listed under the ADDRESSES
section. Include "Docket No. FAA-
2016-6144; Directorate Identifier 2015-
NM-088-AD" at the beginning of your
comments. We specifically invite
comments on the overall regulatory,
economic, environmental, and energy
aspects of this proposed AD. We will
consider all comments received by the
closing date and may amend this
proposed AD because of those
comments.
We will post all comments we
receive, without change, to hap://
www.regulations.gov, including any
personal information you provide. We
will also post a report summarizing each
substantive verbal contact we receive
about this proposed AD.
Discussion
The FAA has examined the
underlying safety issues involved in fuel
tank explosions on several large
transport airplanes, including the
adequacy of existing regulations, the
service history of airplanes subject to
those regulations, and existing
maintenance practices for fuel tank
systems. As a result of those findings,
we issued a regulation titled "Transport Airplane Fuel Tank System Design
Review, Flammability Reduction and
Maintenance and Inspection
Requirements" (66 FR 23086, May 7,
2001). In addition to new airworthiness
standards for transport airplanes and
new maintenance requirements, this
rule included Special Federal Aviation
Regulation No. 88 ("SFAR 88"),
Amendment 21-78. Subsequently,
SPAR 88 was amended by: Amendment
21-82 (67 FR 57490, September 10,
2002; corrected at 67 FR 70809,
November 26, 2002) and Amendment
21-83 (67 FR 72830, December 9, 2002;
corrected at 68 FR 37735, June 25,2003,
to change "21-82" to "21-83").
Among other actions, SFAR 88
requires certain type design (i.e., type
certificate (TC) and supplemental type
certificate (STC)) holders to substantiate
that their fuel tank systems can prevent
ignition sources in the fuel tanks. This
requirement applies to type design
holders for large turbine-powered
transport airplanes and for subsequent
modifications to those airplanes. It
requires them to perform design reviews
and to develop design changes and
maintenance procedures if their designs
do not meet the new fuel tank safety
standards. As explained in the preamble
to the rule, we intended to adopt
airworthiness directives to mandate any
changes found necessary to address
unsafe conditions identified as a result
of these reviews.
In evaluating these design reviews, we
have established four criteria intended
to define the unsafe conditions
associated with fuel tank systems that
require corrective actions. The
percentage of operating time during
which fuel tanks are exposed to
flammable conditions is one of these
criteria. The other three criteria address
the failure types under evaluation:
Single failures, combination of failures,
and unacceptable (failure) experience.
For all three failure criteria, the
evaluations included consideration of
previous actions taken that may mitigate
the need for further action.
We have determined that the actions
identified in this proposed AD are
necessary to reduce the potential of
ignition sources inside fuel tanks,
which, in combination with flammable
fuel vapors, could result in fuel tank
explosions and consequent loss of the
airplane.
Model A320/330/340 FQIS Design
The design of the in-tank FQIS
components and wiring has the
potential for a latent FQIS electrical
fault condition inside the fuel tank
combined with an electrical hot short
condition connecting a high power source to the FQIS wiring to cause an
ignition source in a fuel tank.
Under the policy contained in FAA
Policy Memo PS-ANM100-2003-112-
15, SFAR 88—Mandatory Action
Decision Criteria, dated February 25,
2003 (http://refee.gov/Regulatozy
and Guidence_Library/reolicy.nsf/0/
dc94c3a46396950386256d5e006aed11/
$F1LE/Feb2503.pdf), the FAA
determined that this ignition source risk
combined with the fleet average
flammability for the center wing tank on
airplanes affected by this NPRM created
an unsafe condition for the center fuel
tank. Applying that same policy, the
FAA determined that due to a lower
fleet average flammability, that same
unsafe condition does not exist in the
main wing tanks (inner and outer) and
tail trim tank of these airplanes.
Related Rulemaking
On March 21,2016, we issued AD
2016-07-07, Amendment 39-18452 (81
FR 19472, April 5,2016), for certain
Boeing Model 757-200, —200PF,
—200CB, and -300 series airplanes. AD
2016-07-07 requires similar actions to
those proposed in this NPRM. AD 2016-
07-07 addressed the numerous public
comments that were submitted on the
proposal.
FAA's Determination
This product has been approved by
the aviation authority of another
country, and is approved for operation
in the United States. We are proposing
this AD because we evaluated all the
relevant information and determined
the unsafe condition described
previously is likely to exist or develop
in other products of the same type
design.
In accordance with FAA policy memo
SFAR 88—Mandatory Action Decision
Criteria, dated February 25,2003, we
have determined that the unsafe
condition warrants issuance of an AD to
mandate the actions proposed in this
NPRM.
Proposed AD Requirements
This proposed AD would require
modifying the FQIS to prevent
development of an ignition source
inside the center fuel tank due to
electrical fault conditions. As an
alternative for cargo airplanes, this
proposed AD would provide the
alternative to modify the airplane by
separating FQIS wiring routed between
the fuel quantity indicating (FQI)
computer and the center fuel tank,
provided repetitive BITE (built-in test
equipment) checks of the FQI computer
are also performed.
EFTA00792636
Federal Register/ Vol. 81, No. 85 / Tuesday, May 3, 2016 / Proposed Rules 26489
Costs of Compliance
Wo estimate that this proposed AD
affects I airplane of U.S. registry.
Wo also estimate that it would take
about 1,200 work•hours per product to
comply with the basic requirements of
this proposed AD. The average labor
rate is $85 per work•hour. We have
received no definitive data that would
enable us to provide cost estimates for
the parts needed to do the actions
specified in this proposed AD. Based on
these figures, we estimate the labor cost
of this proposed AD on U.S. operators
to be $102,000.
We have not received definitive
information on the costs for the
alternative wire separation modification
specified in this NPRM. The cost for this
action in similar rulemaking on other
airplanes, however, suggests that this
modification could take about 74 work-
hours with parts costing about $10,000,
for a total estimated cost to U.S.
operators of $16,290 per product.
We estimate that the repetitive FQIS
tank circuit checks associated with the
alternative wire separation modification
would take about I work-hour per
check. We estimate the cost of this
check on U.S. operators to be $85 per
product, per check.
Authority for This Rulemaking
Title 49 of the United States Code
specifies the FAA's authority to issue
rules on aviation safety. Subtitle I,
section 106, describes the authority of
the FAA Administrator. Subtitle VII:
Aviation Programs, describes in more
detail the scope of the Agency's
authority.
We are issuing this rulemaking under
the authority described in Subtitle VII,
Part A, Subpart III, Section 44701:
"General requirements." Under that
section, Congress charges the FAA with
promoting safe flight of civil aircraft in
air commerce by prescribing regulations
for practices, methods, and procedures
the Administrator finds necessary for
safety in air commerce. This regulation
is within the scope of that authority
because it addresses an unsafe condition
that is likely to exist or develop on
products identified in this rulemaking
action.
Regulatory Findings
We determined that this proposed AD
would not have federalism implications
under Executive Order 13132. This
proposed AD would not have a
substantial direct effect on the States, on
the relationship between the national
Government and the States, or on the
distribution of power and
responsibilities among the various
levels of government. For the reasons discussed above, I
certify this proposed regulation:
(1) Is not a "significant regulatory
action" under Executive Order 12866,
(2) Is not a "significant rule" under
the DOT Regulatory Policies and
Procedures (44 FR 11034, February 26,
1979),
(3) Will not affect intrastate aviation
in Alaska, and
(4) Will not have a significant
economic impact, positive or negative,
on a substantial number of small entities
under the criteria of the Regulatory
Flexibility Act.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft. Aviation
safety, Incorporation by reference,
Safety.
The Proposed Amendment
Accordingly, under the authority
delegated to me by the Administrator,
the FAA proposes to amend 14 CFR part
39 as follows:
PART 39—AIRWORTHINESS
DIRECTIVES
■ 1. The authority citation for part 39
continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113. 44701.
§39.13 (Amended)
■ 2. The FAA amends § 39.13 by adding
the following new airworthiness
directive (AD):
Airbus: Docket No. FAA-2016-6144:
Directorate Identifier 2015—NM-088—AD.
(a) Comments Due Date
We must receive comments by June 17.
2016.
(b) Affected ADs
None.
(c) Applicability
This AD applies to the Airbus airplanes.
certificated in any category. identified in
paragraphs (c)(1) through (c)(6) of this AD.
except airplanes equipped with a
flammability reduction means (FRM)
approved by the FAA as compliant with the
Fuel Tank Flammability Reduction (FTFR)
rule (73 FR 42444, July 21. 2008)
requirements of 14 CFR 25.981(b) or 14 CFR
26.33(c)(1).
(1) Airbus Model A318-111,-112. —121.
and —122 airplanes.
(2) Airbus Model A319-111, —112. —113.
—114. —115.-131, —132. and —133 airplanes.
(3) Airbus Model A320-211, -212. -214.
-231. -232. and -233 airplanes.
(4) Model A330-201. -202.-203, -223.
-223F. -243. and -243F airplanes.
(5) Model A330-301. —302.-303, —321.
—322. —323.-341, —342. and —343 airplanes
fitted with a center fuel tank.
(6) Model A340-211. —212.-213, —311.
—312. —313.—541, and —642 airplanes. (d) Subject
Air Transport Association (ATA) of
America Code 28. Fuel.
(e) Unsafe Condition
This AD was prompted by fuel system
reviews conducted by the manufacturer. We
are issuing this AD to prevent ignition
sources inside the center fuel tank, which, in
combination with flammable fuel vapors,
could result in a fuel tank explosion and
consequent loss of the airplane.
(f) Compliance
Comply with this AD within the
compliance times specified. unless already
done.
(g) Modification
Within 60 months after the effective date
of this AD. modify the fuel quantity
indicating system (FQIS) to prevent
development of an ignition source inside the
center fuel tank due to electrical fault
conditions. using a method approved by the
Manager. International Branch. ANM-116.
Transport Airplane Directorate. FAA.
(h) Alternative Actions for Cargo Airplanes
For airplanes used exclusively for cargo
operations: As an alternative to the
requirements of paragraph (g) of this AD. do
the actions specified in paragraphs (h)(1) and
(h)(2) of this AD. To exercise this alternative.
operators must perform the first inspection
required under paragraph (h)(1) of this AD
within 6 months after the effective date of
this AD. To exercise this alternative for
airplanes returned to service after conversion
of the airplane from a passenger
configuration to an all-cargo configuration
more than 6 months after the effective date
of this AD. operators must perform the first
inspection required under paragraph (h)(1) of
this AD prior to further flight after the
conversion.
(1) Within 6 months after the effective date
of this AD. record the existing fault codes
stored in the fuel quantity indicating (FQI)
computer. and then do a BITE check (check
of built-in test equipment) of the FQI
computer. using a method approved by the
Manager. International Branch. ANM-116.
Transport Airplane Directorate. FAA. If any
fault code is recorded prior to the BITE check
or as a result of the BITE chock. before
further flight. do all applicable repairs and
repeat the BITE check until a successful test
is performed with no fault found. using a
method approved by the Manager.
International Branch. ANM-116. Transport
Airplane Directorate. FAA. Repeat these
actions thereafter at intervals not to exceed
650 flight hours. Modification as specified in
paragraph (h)(2) of this AD does not
terminate the repetitive BITE check
requirement of this paragraph.
(2) Within 60 months after the effective
date of this AD. modify the airplane by
separating FQIS wiring that runs between the
FQI computer and the center fuel tank wall
penetrations. including any circuits that
might pass through a main fuel tank. from
other airplane wiring that is not intrinsically
safe. using methods approved by the
Manager. International Branch. ANM-116.
Transport Airplane Directorate. FAA.
EFTA00792637
26490 Federal Register / Vol. 81, No. 85 / Tuesday, May 3, 2016/Proposed Rules
(i) Alternative Methods of Compliance
(AMOCs)
(1) The Manager. International Branch.
ANM-116. FAA. has the authority to approve
AMOCs for this AD. if requested using the
procedures found in 14 CFR 39.19. In
accordance with 14 CFR 39.19. send your
request to your principal inspector or local
Flight Standards District Office. as
appropriate. If sending information directly
to the manager of the ACO. send it to the
attention of the person identified in
paragraph (j) of this AD.
(2) Before using any approved AMOC.
notify your appropriate principal inspector.
or lacking a principal inspector, the manager
of the local flight standards district office/
certificate holding district office.
(9 Related Information
For more information about this AD.
contact Dan Rodina. Aerospace Engineer,
International Branch. ANM-116. Transport
Airplane Directorate. FAA. 1601 Lind
Avenue SW.. Renton. WA 98057-3356:
telephone 425-227-2125: fax 425-227-1149.
Issued in Renton, Washington. on April 15.
2016.
Victor Wicldund,
Acting Manager. Transport Airplane
Directorate. Aircraft Certification Service.
IFR Doc. 2016-09789 Filed 5-2-16: t45 arol
OILLING CODE 4910-18-11
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2016-6145; Directorate
Identifier 2015-NM-056-AD]
RIN 2120-AA64
Airworthiness Directives; The Boeing
Company Airplanes
AGENCY: Federal Aviation
Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking
(NPRM).
SUMMARY: We propose to adopt a new
airworthiness directive (AD) for certain
The Boeing Company Model 747-400,
747-400D, and 747-400F series
airplanes. This proposed AD was
prompted by fuel system reviews
conducted by the manufacturer. This
proposed AD would require modifying
the fuel quantity indicating system
(FQIS) to prevent development of an
ignition source inside the center fuel
tank due to electrical fault conditions.
This proposed AD would also provide
alternative actions for cargo airplanes.
We are proposing this AD to prevent
ignition sources inside the center fuel
tank, which, in combination with
flammable fuel vapors, could result in a fuel tank explosion and consequent loss
of the airplane.
DATES: We must receive comments on
this proposed AD by June 17, 2016.
ADDRESSES: You may send comments,
using the procedures found in 14 CFR
11.43 and 11.45, by any of the following
methods:
• Federal eRulemaking Portal: Go to
http://www.regulations.gov. Follow the
instructions for submitting comments.
• Fax: 202-493-2251.
• Mail: U.S. Department of
Transportation, Docket Operations, M-
30, West Building Ground Floor, Room
W12-140, 1200 New Jersey Avenue SE.,
Washington, DC 20590.
• Hand Delivery: Deliver to Mail
address above between 9 a.m. and 5
p.m., Monday through Friday, except
Federal holidays.
For service information identified in
this NPRM, contact Boeing Commercial
Airplanes, Attention: Data & Services
Management, P.O. Box 3707, MC 21-I-65,
Seattle, WA 98124-2207; telephone
206—544-5000, extension 1; fax 206-
766-5680; Internet https://
www.mybeeingfleet.com. You may view
this referenced service information at
the FAA, Transport Airplane
Directorate, 1601 Lind Avenue SW.,
Renton, WA. For information on the
availability of this material at the FAA,
call 425-227-1221. It is also available
on the intemet at http://
www.regulations.gov by searching for
and locating Docket No. FAA-2016-
6145.
Examining the AD Docket
You may examine the AD docket on
the Internet at http://
www.regulations.gov by searching for
and locating Docket No. FAA-2016-
6145; or in person at the Docket
Management Facility between 9 a.m.
and 5 p.m., Monday through Friday,
except Federal holidays. The AD docket
contains this proposed AD, the
regulatory evaluation, any comments
received, and other information. The
street address for the Docket Office
(phone: 800-647-5527) is in the
ADDRESSES section. Comments will be
available in the AD docket shortly after
receipt.
FOR FURTHER INFORMATION CONTACT: Jon
Regimbal, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA,
Seattle Aircraft Certification Office
(ACO), 1601 Lind Avenue SW., Renton,
WA 98057-3356; phone: 425-917-6506;
fax: 425-917-6590; email:
lon.Regimbalefaa.gov.
SUPPLEMENTARY INFORMATION: Comments Invited
We invite you to send any written
relevant data, views, or arguments about
this proposal. Send your comments to
an address listed under the ADDRESSES
section. Include "Docket No. FAA-
2016-6145; Directorate Identifier 2015-
NM-056-AD" at the beginning of your
comments. We specifically invite
comments on the overall regulatory,
economic, environmental, and energy
aspects of this proposed AD. We will
consider all comments received by the
closing date and may amend this
proposed AD because of those
comments.
We will post all comments we
receive, without change, to http://
www.regulations.gov, including any
personal information you provide. We
will also post a report summarizing each
substantive verbal contact we receive
about this proposed AD.
Discussion
The FAA has examined the
underlying safety issues involved in fuel
tank explosions on several large
transport airplanes, including the
adequacy of existing regulations, the
service history of airplanes subject to
those regulations, and existing
maintenance practices for fuel tank
systems. As a result of those findings,
we issued a regulation titled "Transport
Airplane Fuel Tank System Design
Review, Flammability Reduction and
Maintenance and Inspection
Requirements" (66 FR 23086, May 7,
2001). In addition to new airworthiness
standards for transport airplanes and
new maintenance requirements, this
rule included Special Federal Aviation
Regulation No. 88 ("SPAR 88"),
Amendment 21-78. Subsequently,
SF/AR 88 was amended by: Amendment
21-82 (67 FR 57490, September 10,
2002; corrected at 67 FR 70809,
November 26, 2002) and Amendment
21-83 (67 FR 72830, December 9, 2002;
corrected at 68 FR 37735, June 25, 2003,
to change "21-82" to "21-83").
Among other actions, SFAR 88
requires holders of certain type designs
(i.e., type certificates (TCs) and
supplemental type certificate (STCs)) to
substantiate that their fuel tank systems
can prevent ignition sources in the fuel
tanks. This requirement applies to type
design holders for large turbine-
powered transport airplanes and for
subsequent modifications to those
airplanes. It requires them to perform
design reviews and to develop design
changes and maintenance procedures if
their designs do not meet the new fuel
tank safety standards. As explained in
the preamble to the rule, we intended to
EFTA00792638