i'm looking to find out the correct procedure for when start valve will not close after main engine start on airbus or boeing aircraft.
737NG
Start the Engine Procedure (Normal Start) [TASK 71-00-00-800-808-F00]
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If the starter disengaged at more than 56% N2 or does not disengage, do these steps:
(a) Manually put the start switch to the OFF position.
(b) Look at the center DU to see if the START VLV OPEN maintenance message goes out.
(c)
If the START VLV OPEN maintenance message does not go out, move the start lever to the CUTOFF position to stop the engine
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HIH
Ingo