Top Level Aircraft Requirements relaxation for a single-aisle aircraft: a case study on fleet-wide CO2 emissions and economic impacts

Reducing aviation climate impact is a priority for the stakeholders of the sector, but doing so requires increased investments and progress in aircraft technology, low-carbon fuels, and operations. Aircraft are generally very versatile, leading to missions that are far from the ones they have been designed and optimized for. A potential lever for CO2 reduction in aviation is to have an overall fleet that is better tailored and optimized for the needs of the air transport system. Aircraft are generally designed with a set of top-level aircraft requirements to ensure they match operational constraints. This paper proposes to relax these requirements to assess the effects of lower-range, slower and modified payload aircraft, and evaluate the potential gains for the air transport system. Per-passenger and kilometer fuel burn and operating costs of several modified aircraft are compared with a baseline aircraft using a payload-range response surface. It allows a quick estimation of any mission fuel burn and operating cost. United States-wide operations emissions abatement potential is assessed by replacing the reference fleet with the newly designed aircraft when it is more efficient. Marginal fuel burn gains of 6 % are found when a shorter-range aircraft is designed. An illustrative slower open-rotor aircraft would not significantly increase its operating costs. Increasing the capacity offers both cost and fuel burn reductions but decreases the operating versatility.