Description / Abstract:
This SAE Aerospace Recommended Practice (ARP) provides guidance
for a means of showing compliance with the regulations for hazards
caused by the lightning environment to electrical/ electronic
systems installed either on or within aircraft. Equipment hazards
addressed include those due to indirect effects on equipment and
its associated wiring that is mounted on the aircraft exterior as
well as indirect effects on equipment and its associated wiring
located within the aircraft interior. This document applies to new
aircraft and equipment designs, modifications of existing aircraft
or equipment, and applications of existing (off the shelf)
equipment on new aircraft.
NOTE: This ARP does not address direct effects such as burning,
eroding, blasting, of aircraft structure nor does it address fuel
ignition hazards (see related reading material in 2.3 of this
document). This ARP does not address lightning zoning methods or
lightning test requirements, methods, and techniques. Coverings
(fairing, skin, cowl, etc.) should normally prevent direct
attachment of the lightning channel to underlying system
components. However, if a direct lightning strike attachment to a
system component can occur, a complete evaluation of both direct
and indirect effects will be necessary.
It should be noted that electrical/electronic systems or
components are sometimes exposed to lightning currents directly
conducted from the aircraft exterior, as may happen when an antenna
is struck and a portion of lightning current flows in its cable.
Care should be taken to identify any such possibilities and either
eliminate these situations by design modifications, or address them
in the certification plan. No further discussion of these
situations is included in this ARP.
Purpose:
This ARP provides information and guidance concerning a means,
but not the only means, of compliance with Parts 23, 25, 27, and 29
of the Federal Aviation Regulations (FAR) and Joint Airworthiness
Requirements (JAR), as applicable for preventing hazards, due to
lightning indirect effects, from occurring to electrical/electronic
systems.