Consultation expired with comments. The proposed Certification Memorandum (CM) has been updated based on the comments received, and the corresponding Comment-Response Document (CRD) has been completed by EASA.
Details
Identification of issue
The purpose of this Certification Memorandum is to provide guidance regarding the installation of (small or large) antennas mounted on top of the pressurised (forward or aft) fuselage[1] of large aeroplanes (CS-25). Antenna installations on aircraft are becoming more and more common due to operational and commercial needs and demands. Based on experience acquired on many certification programmes, EASA is of the opinion that further guidance is needed in relation to antenna installations, to clarify the most relevant applicable structural requirements and acceptable means of compliance. This applies to all applicants and is especially important for supplemental type certificate (STC) applicants who are non-type certificate holders (non-TCH), as they may not have access to all type certificate holder (TCH) data required for such installations. The applicant is at any time free to propose an alternative means of compliance.
The safety issues associated with antenna installations are mainly related to their size, shape, location and their attachment means. These aspects of antenna installations may determine the effect on, for example the stability& control, aeroelastic behaviour or damage tolerance characteristics of the aircraft. Compliance with the applicable certification specifications is also aimed at avoiding antenna separation or (partial) break-up, which may result in impact of debris on other structural elements or systems of the aircraft and could also jeopardize persons on the ground. This CM therefore provides guidance, making a distinction between “large” and “small” antenna installations, which may help applicants to define the extent to which compliance with the various applicable specifications has to be shown.
The focus of this CM is on structural (related) certification specifications associated with antenna installations, and/or the effect(s) such antenna installations may have on aircraft structure or on persons on the ground. Other airworthiness (e.g. systems related) or environmental requirements, that are not part of this CM, however may also apply and would have to be considered.