For powerplant and auxiliary power unit installations the following
apply:
(a) Each exhaust system must ensure safe disposal of exhaust gases
without fire hazard or carbon monoxide contamination in any personnel
compartment.
(b) Each exhaust system part with a surface hot enough to ignite
flammable fluids or vapors must be located or shielded so that leakage
from any system carrying flammable fluids or vapors will not result in a
fire caused by impingement of the fluids or vapors on any part of the
exhaust system including shields for the exhaust system.
(c) Each component upon which hot exhaust gases could impinge, or that
could be subjected to high temperatures from exhaust system parts, must be
fireproof. Each exhaust system component must be separated by a fireproof
shield from adjacent parts of the rotorcraft that are outside the engine
and auxiliary power unit compartments.
(d) No exhaust gases may discharge so as to cause a fire hazard with
respect to any flammable fluid vent or drain.
(e) No exhaust gases may discharge where they will cause a glare
seriously affecting pilot vision at night.
(f) Each exhaust system component must be ventilated to prevent points
of excessively high temperature.
(g) Each exhaust shroud must be ventilated or insulated to avoid,
during normal operation, a temperature high enough to ignite any flammable
fluids or vapors outside the shroud.
(h) If significant traps exist, each turbine engine exhaust system must
have drains discharging clear of the rotorcraft, in any normal ground and
flight attitudes, to prevent fuel accumulation after the failure of an
attempted engine start. (Secs. 313(a), 601, and 603, 72 Stat. 752,
755, 49 U.S.C. 1354(a), 1421, and 1423; sec. 6(c), 49 U.S.C. 1655 (c))