Working Paper
Aircraft efficiency metrics: Mass as a “What Is Transported” Term in Efficiency Standards
Recent ICAO deliberations have highlighted some of the tradeoffs faced by including or excluding aircraft and/or fuel mass in an aircraft efficiency metric. This paper, presented to the third CO2 TG meeting of the International Civil Aviation Organization’s Committee on Aviation Environmental Protection, 20–22 September 2010, introduces the U.S. Corporate Average Fuel Economy (CAFE) program for passenger vehicles as a case study to demonstrate how metrics that include vehicle and/or fuel weight could potentially relax incentives for manufacturers to devote technological improvements to reducing fuel consumption rather than boosting performance. In addition, the authors show how the behaviour of metrics that include non-payload mass elements may diverge from real vehicle and fleetwide efficiency trends where large increases in vehicle performance occur over time.