How Aircraft Turbo Jet Engine Start | How Engine Starts With Bleed Air From Auxiliary Power Unit

Aircraft Turbo Jet Engine Start Procedure

Engine Starts With Bleed Air From Auxiliary Power Unit (APU)

- APU has an electric starter.

- APU is started with the help of Ground Power Unit (GPU).

- As APU starts, APU takes bleed air and ducted to engine air starter through starter shut off valve.

- Air Starter will convert pneumatic energy into rotational (mechanical) energy and turns the Main Gear Box. (Accessory Gear Box -AGB).

- Main Gear Box (MGB) drives the Transfer Gear Box (TGB).

- The TGB is connected to the High Pressure Compressor (HPC) Shaft of the engine, which is then rotated.

- Then after Fuel Scheduling System (FSS) schedule fuel and deliver it to the combustion chamber. The fuel is mixed with the airflow supplied by the HPC and then burned in the chamber.

- After starts the engine shaft due to process in combustion chamber. as the turbine shaft rotates, so will rotate the compressor shaft because they are connected to same shaft.

- Thus the engine is started.