A320 Eng Start question
 

A320 V2500 Engine

Folks why is it that after an automatic (fadec) aborted engine start (and after 30 sec dry crank sequence) do we need to do a manual engine start ?

Why not do another automatic engine start ?

I initially thought that maybe we need both igniters but according to fcom - an automatic engine start after aborted start does use both igniters....I can't seem to find the reason for a manual start....

I know when a manual start needs to be performed - My question is WHY do we do it ?

After paging through the V2500 technical manual I'm still clueless ?

Maybe it's part of the FADEC at fault that will not allow a complete start.
Would have to review the manual for comfirmation on that...without knowing what fault occurred or observation, unless this is a theory question.

I have personally seen a successful automatic engine start after an aborted start.

So I have no idea why we use the manual start function.

I suppose it varies by the operator, but at our airline a manual start after a start abort is not REQUIRED, but is RECOMMENDED, and yes, it's entirely possible you'll get a successful auto start after an abort, but a manual start gives you more control over the starting process, which could prevent another abort, depending upon what the original abort was for. For instance, if the abort was because FADEC introduced fuel too early, a manual start would prevent that.