DOC AIRBUS | AMM A320FCRANKING - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. Air Supply
The air necessary for the starting comes from the duct connecting engine bleed and the precooler via a 4 in.dia. duct.
The air necessary for the starter is supplied by either:
** ON A/C NOT FOR ALL The air necessary for the starting comes from the duct connecting engine bleed and the precooler via a 4 in.dia. duct.
The air necessary for the starter is supplied by either:
- the other engine through the crossbleed system
- the APU and in that case, all the air bled from the APU is used for starting
- an external source able to supply a pressure between 30 and 40 psig.
2. Dry Cranking
A. Requirement
(1) A dry motoring of the engine will be needed when:
- It is necessary to eliminate any fuel accumulated in the combustion chamber
- A leak check of engine systems is needed.
To perform this operation, the starter is engaged and the engine is motored but the HP fuel shut off valve remains closed and both ignition systems are OFF.
An engine dry motoring can be performed for a maximum of three consecutive cycles (2 of 2 minutes and 1 of 1 minute with a cooling period of 15 seconds between each cycles).
After three cycles or 4 minutes of continuous cranking, stop for a cooling period of 30 minutes.
B. Dry cranking control
(1) A selector switch is located on ENG panel 115VU.
C. Automatic Dry Cranking
An automatic selection of dry cranking is accomplished during the engine start procedure (when the ENG/MASTER control switch is set to ON) and when the starting sequence is aborted by the FADEC. This can be interrupted at any time by placing the MASTER control switch in OFF position.
An automatic selection of dry cranking is accomplished during the engine start procedure (when the ENG/MASTER control switch is set to ON) and when the starting sequence is aborted by the FADEC. This can be interrupted at any time by placing the MASTER control switch in OFF position.
3. Wet Cranking
A. Requirement
A wet motoring will be needed when the integrity of the fuel system has to be checked.
If such a test is performed, both ignition systems are off and the starter is engaged to raise N2 up to the required speed of 20%. The MASTER control switch is moved to ON and the exhaust nozzle of the engine carefully monitored to detect any trace of fuel.
The wet motoring can be performed for a maximum of three consecutive cycles (2 of 2 minutes and 1 of 1 minute with a cooling period of 15 seconds between each cycles).
After three cycles or 4 miutes of continuous cranking, stop for a cooling period of 30 minutes.
In all cases, the MASTER control switch will be returned to OFF and the engine motored for at least 30 seconds to eliminate entrapped fuel or vapor.
A wet motoring will be needed when the integrity of the fuel system has to be checked.
If such a test is performed, both ignition systems are off and the starter is engaged to raise N2 up to the required speed of 20%. The MASTER control switch is moved to ON and the exhaust nozzle of the engine carefully monitored to detect any trace of fuel.
The wet motoring can be performed for a maximum of three consecutive cycles (2 of 2 minutes and 1 of 1 minute with a cooling period of 15 seconds between each cycles).
After three cycles or 4 miutes of continuous cranking, stop for a cooling period of 30 minutes.
In all cases, the MASTER control switch will be returned to OFF and the engine motored for at least 30 seconds to eliminate entrapped fuel or vapor.
B. Wet Cranking Control
(1) A selector switch is located on the ENG panel 115VU.