§29.1191 Firewalls

(a) Each engi ne, i ncluding t he com bustor, turbine, and tailpipe sectio ns o f tu rbine en gine installations, m ust b e iso lated b y a firewall, shroud, or equi valent m eans, from personnel compartments, structures, controls, rotor mechanisms, and other parts that are: (1) Essential to co ntrolled flig ht an d landing; and (2) Not protected under CS 29.861. (b) Each auxiliary p ower u nit, co mbustion heater, and ot her com bustion equi pment t o be used in flight, must be isolated fro m th e rest o f th e rotorcraft by firewalls, shrouds, or equivalent means. (c) Each firewall or shroud m ust be constructed so that no hazardous quantity of air, fluid, or fl ame can pass from any engine compartment to other parts of the rotorcraft. (d) Each openi ng i n t he fi rewall or shroud must b e sealed with close-fitting fireproof grommets, bushings, or firewall fittings. (e) Each firewall and shroud m ust be fireproof and protected against corrosion. (f) In meeting this paragraph, account m ust be taken of t he probable path of a fire as affected by the airflow in normal flight and in autorotation.