Start faults on A320 with CFM

[C.M]

Hello
I’ve been operating on Airbus with CFM almost a year now . Coming from A320 with IAE and having experienced a few start faults in actual operations ( and simulator ) I want to clarify some differences I saw in the FCOM on this issue. Here is the FCOM extract I want to clarify
On the ground (auto start) : L2 If the engine does not start, the FADEC can attempt an additional engine restart. After any start attempt that is not successful, a dry crank phase automatically occurs. The ECAM displays the following messages:
L1 AUTO CRANK IN PROGRESS
NEW START IN PROGRESS
-When the final dry cranking process is finished: ENG MASTER (AFFECTED)..............................................OFF

It seems to me that the FCOM suggests that the FADEC will attempt several auto-cranks followed each time by a start attempt . This is definitely not how an IAE engine would behave ( IAE only displays and performes 1 Dry crank . There is no display of “New start in progress” ecam , nor have I seen one been attempted even without the ECAM saying so )

If you have seen it can you please comment on your experience?

[applecrumble]

I have operated both types of engine.
If the CFM autostart fails then it can perform up to 3 start attempts each with a dry crank in-between. The FADEC will perform this automatically reducing the fuel schedule in stages but using both ignitors.
The IAE is different as it would NOT perform another autostart after a start failure the ECAM will just display ENGINE MASTER (AFFECTED 1(2)) .......... OFF after it has performed an auto crank.
I hope that helps.

[C.M]

Thank you applecrumble . It answers exactly what I was looking for , for CFM

[k.swiss]

With regards to ENG crank, when a dry crank is required is it necessary to switch APU BLEED on? I am confused if the switch is in crank is that enough or does there need to be an air source like BLEED to turn the engine.

Thank you.

[pineteam]

Yes you need APU BLEED or any other bleed source ( from other engine, Air Start Unit) you were using to start the engine at the first place.

[k.swiss]

Thank you, makes sense.