Note: Size related to seat capacity, two class configuration.
Source: adapted from IEA/OECD (2009) Transport, Energy and CO2:
Moving toward sustainability. Paris: International Energy
Trends in Fuel Efficiency, Selected Passenger Jet Planes
Fuel efficiency is an important component of aircraft
operations, so the evolution of jet planes goes on par with the
evolution of their fuel efficiency (here measured in mega joules
per passenger-km). Several factors contributed to the
improvements in energy efficiency of aircraft in recent decades:
An important landmark was achieved in the early 1970s with
the introduction of second generation jet planes (B747 and DC10)
that included engine efficiency improvements as well as the
economies of scale benefits of high capacities, in the range of
300 to 400 passengers. Structural efficiency improvements, such
as weight reduction, made limited contribution to improved energy efficiency. Rising energy prices have several impacts on airline companies. One
involves switching to more fuel efficient aircrafts and retiring
those that are less.
- Improvements in engine fuel per unit of thrust: About 70%.
- Aerodynamic improvements: About 25%.
- Other factors such as economies of scale of larger aircraft: