Benchmarking aircraft metabolism based on a Sustainable Airline Index

Airlines are mobile, micro-communities that exhibit varying levels of performance. This paper develops and applies a composite indicator to address a gap in the literature for benchmarking airlines based on aspects of sustainable aviation. First, the concept of aircraft metabolism is developed to relate flows of energy, carbon dioxide emissions, water, and waste with operational outputs, such as the transport of revenue loads. The Sustainable Airline Index is then constructed based on 4 dimensions and 20 indicators to benchmark aircraft metabolism. The dimensions are 1) airline services and quality, 2) fuel consumption and efficiency, 3) carbon dioxide emissions and intensity, and 4) sustainable aviation measures. The index is applied to a sample of 16 airlines based on data from corporate sustainability reporting and annual reports. The results are compared based on six schemes that involve equal or unequal weights with linear or geometric aggregation. Unequal weights are determined based on exploratory factor analysis. The net change in rank among all schemes is 2.3 positions. Monte Carlo experiments are also conducted to rank airlines based on simulated mean values in which the top 4 airlines in the sample are A9, A11, A3 and A15. Airlines that decouple revenue loads from similar increases in resource usage have higher rankings in the composite indicator based on well-rounded performances in aircraft metabolism. The results are applicable to support the carbon neutral growth strategy of the sector and to consider multiple dimensions towards more sustainable practices on the airside of aviation.