Abstract In this paper, the UNICADO 2. 0 software is used to simulate and evaluate measures regarding the reduction of energy consumption and climate impact of long-range aircraft. For this purpose, an Airbus A350-900-like reference aircraft powered by a Trent XWB-84-like aero engine is generated. The measures investigated are SAF, liquid hydrogen and a reduction in cruise speed. The design of a liquid hydrogen aircraft with cryogenic tanks hereby discloses significant challenges regarding landing gear integration, tail strike and competitive transport work. The combined implemented measures of liquid hydrogen and a reduced cruise speed lead to a maximum reduction, compared to the reference aircraft, in the climate impact of 82% in average temperature potential, 80% in absolute global warming potential and 76% in absolute global temperature potential; however, leading to an increase in fuel consumption of 13. 6% due to the lower cruise Mach number. This and the necessary change to an economy-class-only layout over two passenger decks for the liquid hydrogen configuration show the at times inverse relation of climate impact reduction measures and economic feasibility. Furthermore, the scope of interest is shifted over the system boundaries of the aircraft. Thus, including hydrogen production in the environmental evaluation. Assuming a production in Germany in the year 2022, an increase in the CO₂ equivalent of 156% compared to the reference aircraft is obtained. However, when assuming energy production solely from wind turbines a reduction of 92% is possible.
Barnert et al. (2026) studied this question.