Each engine, auxiliary power unit, fuel-burning heater, or other item of combustion equipment that is intended for operation in flight must be isolated from the rest of the airplane by means of firewalls or shrouds, or by other equivalent means.
authority: 49 U.S.C. 106(f), 106(g), 40103, 40113, 40119, 41706, 42301 preceding note added by Pub. L. 112-95, sec. 412, 126 Stat. 89, 44101, 44701-44702, 44705, 44709-44711, 44713, 44716-44717, 44722, 44729, 44732; 46105; Pub. L. 111-216, 124 Stat. 2348 (
49 U.S.C. 44701 note); Pub. L. 112-95, 126 Stat. 62 (
49 U.S.C. 44732 note); Pub. L. 115-254, 132 Stat. 3186 (
49 U.S.C. 44701 note)
cite as: 14 CFR 121.245