A multi engined aircraft is provided with standardized engine mounting points which enables an engine to be removed from one side of the aircraft and fitted to the opposite side thereof, so as to broaden the range of engine interchangeability.

A turbine driven electrical driven generator set having one or more turbines positioned above the generator to provide a power source at locations where there is a minimum available floor space. An acoustical enclosure enclosing the turbine and generator and having air filters for filtering the generator cooling air and the intake air to the turbine. An air fan driven from the generator for cooling the generator and the oil in the turbine and the reduction gearing between the turbine and the generator through an air/oil heat exchanger. The air fan cooling the turbine after shutdown.

A ram air turbine and deployment mechanism has commonly had power-generating means in the form of either one, or both, of a hydraulic pump and electrical generator mounted at the end of a pivotal strut adjacent the ram air turbine. Relocation of the power-generating means can provide a system with improved operation, lesser weight and other improvements over prior known systems. The ram air turbine is mounted at the end of a pivotal strut for movement between stowed and deployed positions. The electrical generator forms a major part of the strut and is located close to the pivot axis of the strut. The hydraulic pump is mounted to aircraft structure within the stowing compartment of the aircraft and has a driven member aligned with the pivot axis of the pivotal strut. The drive of the generator and the pump is derived from rotation of the rotatable hub assembly of the ram air turbine which drives rotatable shaft means within the strut by a first angled spiral gear drive between the ram air turbine and the generator and a second angled spiral gear drive between the rotatable shaft means within the strut and the driven member of the hydraulic pump. The speed relation between the components is determined by sizing of the gears of the angled spiral gear drives wherein the ram air turbine, the generator, and the hydraulic pump can all be operated at optimum speed to maximize the performance of each of the components.

Drive means for connecting a gas turbine engine to its accessories are so constructed as to allow the accessories to be selectively positioned to any one of several predetermined circumferential positions about the perimeter of the engine. This feature permits convenient mounting of the same engine upon vehicles demanding radically different engine mounting arrangements.

A gas turbine engine has a variable pitch fan and a first compressor mounted on one shaft and driven from a common turbine, together with a high pressure compressor and turbine on a second shaft, ducting to supply bleed air to high lift devices on an aircraft in which the engine is mounted, and means for bleeding air from the first compressor to the high lift devices when the fan blades are turned to fine pitch. A control system is included to maintain the first compressor speed at maximum when the high lift devices are being used.