This Notice of Proposed Amendment (NPA) addresses a safety and regulatory coordination issue related to High-intensity radiated fields (HIRF) and lightning.
Aircraft electrical and electronic equipment can be susceptible to adverse effects from electromagnetic radiation and lightning. With the increased use of critical and essential electrical/electronic systems on aircraft, coupled with the development and use of non-metallic structural materials that are more ‘transparent’ to electromagnetic radiation and have low electrical conductivity, it has been recognised for many years that HIRF and lightning standards must be enhanced to counter the growing threat.
In the field of product certification, EASA is currently reliant upon raising Certification Review Items (CRIs) to introduce Special Conditions (SCs) and Interpretative Material based on JAA interim policies. The approach proposed in this NPA is largely based on the results of the Electromagnetic Effect Harmonisation Working Group (EEHWG). It relies on previous work conducted by EUROCAE and the Society of Automotive Engineers and is coordinated with the FAA to ensure the highest possible level of harmonisation.
EASA considers this NPA necessary on the basis of Article 2 of Regulation (EC) No 216/2008 and, in particular, paragraphs 1 (high uniform level of safety) and 2(e) (cooperation with third countries). The essential requirements for airworthiness, as outlined in Annex I to Regulation (EC) No 216/2008, stipulate in particular in paragraph 2.c.1. that ‘…no unsafe condition must occur from exposure to phenomena such as […] lightning, high frequency radiated fields, […] reasonably expected to occur during product operation.’.
This NPA proposes to amend CS-23, CS-25, CS-27 and CS-29 introducing provisions for protection against HIRF and lightning, and introduce new general AMCs in the AMC-20 series related to the above new requirements.
The proposed changes are expected to reduce regulatory burden and improve harmonisation.