This Certification Memorandum describes a means by which CS-25 Subpart H – EWIS for engine wiring
components may be addressed as part of CS-E compliance, by an applicant for an engine Type Certificate
(TC), Major Change/Repair, Minor Change/Repair, or Supplemental Type Certificate (STC).

The objectives of this Decision are to:
(a) enhance and modernise the certification specifications and acceptable means of compliance for the
installation of flight recorders on board large aeroplanes and large rotorcraft (CS-25 and CS-29), and
(b) amend the certification specifications and acceptable means of compliance for large aeroplanes
following the selection of non-complex, non-controversial and mature subjects (the regular update of
CS-25).
These amendments are expected to increase safety, increase cost-effectiveness and improve harmonisation
with the Federal Aviation Administration (FAA) regulations.

This Decision addresses an environmental issue related to aircraft engine emissions and fuel venting.
The Decision is linked to the ICAO State Letters AN 1/17.14-16/53, AN 1/17.14-16/55 and AN 1/17.14-16/56 on
the adoption of Amendments 12 and 9 to Annex 16 Volumes I and II respectively, and on the adoption of the
First Issue of Annex 16 Volume III.
The specific objective is to provide a high uniform level of environmental protection in the European Union (EU)
as well as a level playing field for all actors in the aviation market by aligning EU legislation with the latest ICAO
Standards and Recommended Practices (SARPs) and guidance material on aircraft noise, aircraft engine
emissions and aeroplane CO2 emissions. The new amendments to these SARPs and guidance material were
approved by the ICAO Committee on Aviation Environmental Protection at its 10th meeting (CAEP/10) in
February 2016 and adopted by the ICAO Council at its 7th meeting of the 210th Session on 3 March 2017.
Amendment 12 to ICAO Annex 16 Volume I introduces updates to the existing aircraft noise measurement
specifications.
Amendment 9 to ICAO Annex 16 Volume II updates existing aircraft engine emissions measurement
specifications, and introduces a new non-volatile particulate matter (nvPM) emissions mass concentration
standard as Chapter 4 into Part III. This is supplemented by Appendix 7 which contains the certification
procedures, including measurement methodology, system operation and instrument calibration.
The new ICAO Annex 16 Volume III introduces an aeroplane CO2 emissions standard for both new and inproduction aeroplane types.
In addition to the amendments to ICAO Annex 16, CAEP/10 approved ICAO Doc 9501 ‘Environmental Technical
Manual’ (ETM), Volume I ‘Procedures for the Noise Certification of Aircraft’, Volume II ‘Procedures for the
Emissions Certification of Aircraft Engines’, and a new Volume III ‘Procedures for the CO2 Emissions Certification
of Aeroplanes’. The updated ETM volumes provide clarifications and additional guidance material to facilitate a
harmonised implementation of ICAO Annex 16.
This Decision incorporates the changes of ICAO Annex 16 Volume II and ICAO ETM Volume II into the
Certification Specifications for Aircraft Engine Emissions and Fuel Venting (CS-34). These changes ensure
compliance with the latest ICAO SARPs on aircraft engine emissions.