DOC AIRBUS | AMM A320FSTARTING - GENERAL - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. General
The start system on the engine is made of the parts that follow:
The main function of the engine starter and valve system is to convert pressurized air to a driving torque necessary to rotate the engine core to a self-sustained speed through combustor ignition.
The engine starting system is located on the engine at approximately 8 o'clock, aft looking forward.
The source of the pressurized air supply is a ground cart, auxiliary power unit, or cross-bleed air from the opposite engine.
The ground start sequence includes additional pre-start motoring to mitigate potential rotor bow due to thermal differences in the engine. The EEC modulates VSV position to maintain lower core speed during the pre-start motoring. If the air supply pressure goes above a certain limit during the pre-start motoring, the EEC can hold the starter air valve to an intermediate position to limit the engine core speed.
The starter air valve is controlled by electrical signals from the Electronic Engine Control (EEC).
If the starter air valve does not respond to cockpit input, the valve may be manually operated in order to start the engine. For a manual starter air valve override start, only APU air may be used to supply the pneumatic pressure for engine starting. The EEC will automatically perform the pre-start motoring while the valve is held open by the maintenance technician.
The start system on the engine is made of the parts that follow:
Starting Components- Air Turbine Starter (ATS)
- Starter Air Valve (SAV)
- Starter Air Duct (SAD).
The main function of the engine starter and valve system is to convert pressurized air to a driving torque necessary to rotate the engine core to a self-sustained speed through combustor ignition.
The engine starting system is located on the engine at approximately 8 o'clock, aft looking forward.
The source of the pressurized air supply is a ground cart, auxiliary power unit, or cross-bleed air from the opposite engine.
The ground start sequence includes additional pre-start motoring to mitigate potential rotor bow due to thermal differences in the engine. The EEC modulates VSV position to maintain lower core speed during the pre-start motoring. If the air supply pressure goes above a certain limit during the pre-start motoring, the EEC can hold the starter air valve to an intermediate position to limit the engine core speed.
The starter air valve is controlled by electrical signals from the Electronic Engine Control (EEC).
If the starter air valve does not respond to cockpit input, the valve may be manually operated in order to start the engine. For a manual starter air valve override start, only APU air may be used to supply the pneumatic pressure for engine starting. The EEC will automatically perform the pre-start motoring while the valve is held open by the maintenance technician.