The engine bay is formed by the sides and undersurface of the fuselage and extends from the nosegear bay back to main gear bay. The engine bay is divided nto two zones (Fig. 4) by a fireproof bulkhead mounted on the engine at the joint between the h.p. compressor delivery casing and the combustion chamber casing. Zone 1 (forward of the bulkhead) contains the compressor sections of the engine, the engine fuel system, oil tank and the engine driven accessories.