NOX emissions

The NO_x standards⁵ for aircraft engines have become more stringent between 1996 and 2014, and are typically referred to by the CAEP meeting in which they were agreed (CAEP/2, CAEP/4, CAEP/6 and CAEP/8)

NO_X performance of new aircraft engine deliveries

illustrates the trend over time of aircraft joining the European fleet and their performance against the various ICAO engine NO_X emissions standards. It highlights that all new aircraft engine deliveries were compliant with at least CAEP/6 by 1 January 2012, thereby meeting the CAEP/6 production cut-off date of 1 January 2013. In addition, all new aircraft engine deliveries have met the latest CAEP/8 NO_X standard from 1 January 2020 onwards, thereby suggesting a need to review this standard within the CAEP/14 work programme (2025-2028).

⁵ NO_x limits are defined as the mass (Dp) of NO_x emitted during the Landing and Take-Off (LTO) test cycle and divided by the thrust of the engine (Foo). The limit also depends on the overall pressure ratio of the engine.

Published in collaboration with