This report assesses how the fuel efficiency of commercial aircraft has developed since their introduction in the 1930s. Existing estimates, such as the oft-cited 70% improvement from the IPCC Special Report on Aviation and the Global Atmosphere, ignore the record of the pre-jet era. Based on bottom-up (micro) and top-down (macro) analyses of aircraft fuel efficiency, it can be concluded that the last piston-powered aircraft were as fuel-efficient as the current average jet. This result was obtained by comparing several large piston-engined aircraft with both old and new jet airliners and was confirmed by the macro analysis, which reveals a sharp increase in fuel consumption per seat-kilometre as piston-engined aircraft were replaced by jet-engined. The last piston-powered airliners were at least twice as fuel-efficient as the first jet-powered aircraft.
A report by the Netherlands National Aerospace Laboratory (NLR).