(a) Each cowling and engine compartment covering must be constructed
and supported so that it can resist the vibration, inertia, and air loads
to which it may be subjected in operation.
(b) Cowling must meet the drainage and ventilation requirements of
(c) On rotorcraft with a diaphragm isolating the engine power section
from the engine accessory section, each part of the accessory section
cowling subject to flame in case of fire in the engine power section of
the powerplant must --
(1) Be fireproof; and
(2) Meet the requirements of §29.1191.
(d) Each part of the cowling or engine compartment covering subject to
high temperatures due to its nearness to exhaust system parts or exhaust
gas impingement must be fireproof.
(e) Each rotorcraft must --
(1) Be designated and constructed so that no fire originating in any
fire zone can enter, either through openings or by burning through
external skin, any other zone or region where it would create additional
(2) Meet the requirements of paragraph (e)(1) of this section with the
landing gear retracted (if applicable); and
(3) Have fireproof skin in areas subject to flame if a fire starts in
or burns out of any designated fire zone.
(f) A means of retention for each openable or readily removable panel,
cowling, or engine or rotor drive system covering must be provided to
preclude hazardous damage to rotors or critical control components in the
event of --
(1) Structural or mechanical failure of the normal retention means,
unless such failure is extremely improbable; or
(2) Fire in a fire zone, if such fire could adversely affect the normal
means of retention. (Secs. 313(a), 601, and 603, 72 Stat. 759, 775,
49 U.S.C. 1354(a), 1421, and 1423; sec. 6(c), 49 U.S.C. 1655(c))