Comparative Analysis on Aircraft Direct Operating Cost Models

Aircraft direct operating cost is a critical performance driver in the air transport industry. Existing DOC models are based on cost estimating relationships developed from historical data covering multiple generations of aircraft. However, these models often produce significantly different estimations. This presents a significant challenge especially when assessing smaller or electrified propulsion aircraft. This study reviews nine different direct operating cost models, highlights their limitations in short-range operations, and introduces a new model specifically adapted for smaller aircraft that may feature electric or hybrid-electric propulsion. The model is complemented with cost elements such as battery depreciation, battery degradation on charging, amortized interest, updated salaries, SAF blending and carbon tax. Application of the proposed model to seven different aircraft revealed that electric configurations progressively achieve lower unit costs throughout the scenarios analyzed, whereas conventional designs become increasingly expensive. Analysis suggests that existing economic predictions are highly sensitive to the chosen model and scenario assumptions.