FOI:s Confidential database for Turboprop Engine Emissions

FOI is the keeper of a confidential database of emission indices (EI) of NOX, HC and CO with corresponding fuel flows for turboprop engines. Datasheets have been supplied by the turboprop engine manufacturers, originally for the purposes of calculating emissions-related landing charges.



The data are presented in the same format as the ICAO (International Civil Aviation Organization) Engine Emissions Database for jet engines, but have not been endorsed by ICAO in a certification process. It should be noted that the data have many inaccuracies resulting primarily from the unregulated test methodologies. The data is however considered as being the best available and may be used for emissions inventories, emissions-related landing charges etc.


There is also a significant issue of an appropriate idle setting for turboprops, see International Coordinating Council of Aerospace Industries Associations recommendations and the FOI study “Methodology for establishing the relation between thrust and power for propeller equipped engines” (FOI-R—0855—SE, October 2003) .


Suggested Times in Mode (TIM) for calculating LTO emissions for turboprops.



Time (Min.)



Climb out






*26 minutes for larger airports (corresponding to ICAO’s emission certification time) and 13 min for small/regional airports if actual taxi times are not known.

To obtain the turboprop emissions database, please send an e-mail to and describe the purpose of use of the database. The database can be distributed on certain conditions and after ICCAIA’s concurrence.


Emissions data for piston-powered aircraft can be found at the Swiss Federal Office of Civil Aviation (FOCA).