Jet Propulsion/Accessories

Gearboxes are used to alter the shaft speeds and provides accessory drives for electrical generators, Fuel pumps, lubrication pumps, and hydraulic pumps. The compressor may provide bleed air which is used for powering the engine lubrication systems, engine clearance control systems, turbine cooling systems, rotor force balancing, aircraft pressurization & airconditioning, aircraft deicing and various other functions. The pressurized fuel is injected into the gas flow by the injectors and ignited by the igniters. The engine is controlled by an electrohydraulic or digital control system and is [[Jet Propulsion/Instruments/|instrumented}} to provide operational, maintenance and health monitoring. The engine is started by a starting system powered by Aerodynamic flows in flight freewheeling Compressed air motor (provided by another engine on the aircraft, e.g. an apu, a windmill, a gas generator, or a ground service vehicle) Electric or hydraulic motor