TW
Since when would there be a partial light off?
Combuster interconnectors or Can Annualar arrangements ensure full light off unless a rare blocked fuel nozzle.
Very true when new
However the combustor and liner have a very hard life and when they erode you do not get the situation as advertised. Several AD to rework and replace the FCL ( Including one last month !) due to - wait for it !! a batch were made forn the wrong material !!
The accel shedule is very critical on start and as engine and FCU get time in sevice some of that margin decreases. A tail wind is also not helpful
for clean starts