Appendix 1: Methodology The analysis presented in this paper is based on a comprehensive and multi-faceted approach, incorporating various data collection methods to ensure a realistic perspective from the Airports of Tomorrow community. The insights presented in this paper are based on the following phases: An extensive desk research exercise conducted during Q1 2025, led by Judge Business School MBA students at Cambridge University, focused on hydrogen buses as the main alternative technology for benchmarking and comparison. The Airports of Tomorrow community validated the different scenarios considered in this phase and the theoretical assumptions utilized, through workshops and bilateral calls. A second phase followed during Q2 2025, in which graduate students from Imperial College London explored battery-electric buses and retrofitted diesel buses, with an emphasis on cost structures, infrastructure requirements and operational suitability. As in the first phase, the Airports of Tomorrow community validated the theoretical assumptions made during the research and provided inputs to ensure both analyses were complementary. Throughout the exercise, over 20 in-depth interviews were conducted with experts drawn from across the airport ecosystem, ensuring coverage of all industry profiles: airport operators, ground handling service providers, bus manufacturers, bus operators, infrastructure developers and energy suppliers. The insights gathered from these different sources were carefully analysed to offer a neutral and objective view of the industry’s challenges and risks. While most of the assumptions used in the TCO model were validated, some were simplified and may not fully reflect the diversity of perspectives across the industry. As a result, the final figures should be seen as well-supported estimates that depend on certain conditions and are limited by the scope of the interviews. Even so, this analysis provides a useful tool to help airports make strategic decisions about transitioning ground service equipment as part of their decarbonization plans. Decarbonizing Aviation Ground Operations: Alternative Bus Technologies 26

Decarbonizing Aviation Ground Operations 2025