The purpose of this Certification Memorandum is to provide specific guidance for certification of external
installations on helicopters, for modifications for which CS 27/29.865 is not applicable. It deals with external
fixtures (see 1.4 Definitions) and devices that are non-extensive in terms of weight, external surface are
and/or volume. Large agricultural kits, external rigid water tanks for fire-fighting operations, collapsible
buckets or external platforms used for Human External Cargo (HEC), hoist and cargo hook installations are
considered to be outside of the scope of this CM.
Additionally this CM provides guidance to ensure the proper classification of design changes involving
external installations and any subsequent modifications to them, either by the original approval holder or
through the STC process by a third party.
Examples of external installations to which this Certification Memorandum is applicable:
 External equipment boxes with fixed equipment (fixed mass and CG)
 Cameras
 Searchlights
 Loudspeakers
This CM focuses on the technical aspects to be considered to certify such installations from the structural
and flight substantiations points of view. Other technical considerations that could affect these installations
(electrical, avionic, environmental, etc.) are not within the scope of this CM.

On 4 September 2019, Commission Regulation (EU) 2019/1384 was published. Said Regulation amends Commission
Regulation (EU) No 965/2012 (the Air OPS Regulation) by introducing new requirements into all Annexes to the
Regulation. The Regulation and consequently this Decision, which contains the related acceptable means of
compliance (AMC) and guidance material (GM), combine the outcome of the following four rulemaking tasks:
— RMT.0516 on an update of the Air OPS Regulation, including an editorial update of AMC & GM and new
provisions on establishment of rules on non-commercial operations with reduced cabin crew on board;
— RMT.0352 on new provisions on the use of aircraft registered on an air operator certificate (AOC) by operators
that are not AOC holders for non-commercial operations or specialised operations, without removing the
aircraft from the AOC;
— RMT.0393 on maintenance check flights; and
— RMT.0561 on in-flight entertainment systems.
In addition to the RMTs mentioned above, this Decision is based on safety recommendations (SRs) regarding air
operations; safety actions deriving from the European Plan for Aviation Safety (EPAS), and amended International
Civil Aviation Organization (ICAO) Standards and Recommended Practices (SARPs). The main objective is to improve
the level of safety. The amendments are expected to increase safety and ensure alignment with ICAO standards.