Abstract: A nacelle of a gas turbine engine is attached via a pylon to an aircraft wing from which the engine is to be mounted. The nacelle is split to form a pair of opposing arcuate doors which are moveable between an open position and a closed position. When the doors are closed a ring on the fan casing locates in a correspondingly shaped groove on the inner surface of the arcuate doors. The nacelle is structurally integrated with the fan casing with the ring so that all the engine loads are transmitted through the nacelle. Telescopic struts are provided to connect the engine casings directly to the pylon so that when the arcuate doors are open, to allow access to the engine, the struts 50-60 support the engine.