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 jetengined.
The last piston-powered airliners were at least twice as fuel-efficient as the
first jet-powered aircraft.
Aircraft fuel efficiency is just one of the design parameters of interest to aircraft
designers and the market. The common practice of defining future cuts in energy
consumption per seat-kilometre in terms of a constant annual percentage reduction is
therefore not very accurate. It ignores the fact that current aircraft configurations can
never achieve zero fuel consumption. Nor does it take into account that the annual
reduction rate is not a constant, but is itself also falling, as clearly demonstrated by
both macro and micro analysis.
According to this report, this means that many studies on predicted future
efficiency gains are rather optimistic.
Interesting read - this is a PDF that is in the direct download mode…
About Cleantech in Aviation
I did my undergraduate degree in aerospace engineering, but pretty much became a turncoat by going for an MBA after that. Guess it is time for me to revisit my original engineering education, and what better way than to look at the intersection between cleantech and aviation / aircraft /… - view more