, and are grouped based on combustor technologies. The Y axis of those figures uses a logarithmic scale to differentiate between combustor types more easily.
Modelling of non-CO2 emissions in cruise
The CAEP/13 work programme (2022-2025) has evaluated the relationship between NOx emissions measured in the reference Annex 16 Volume II certification Landing and Take-Off (LTO) cycle and NOx emissions in cruise. A new cruise NOx Metric System based on LTO data and Annex 16 Volume III fuel burn data is being considered with the aim of improving the modelling of cruise NOx emissions for lean burn engines within the Boeing Fuel Flow Method (BFFM) and the assessment of the effect of non-CO2 emissions on climate change
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In addition, a proposed 5th LTO reporting point for nvPM emissions at a cruise thrust setting (57.5% of maximum sea level static thrust) is proposed to be included in the ICAO Annex 16 Volume II certification requirements to enhance the understanding of engine nvPM emissions and improve cruise nvPM modelling, e.g. within the Mission Emissions Estimation Methodology (MEEM)
