I think I'm coming into this thread late but suspect it has something to do with turning off the engine in flight and if it's something possible to restart easily (hard to tell though, a bunch of posts now just read "oops" and stuff.) Just five minutes ago I put down a book and recall reading this:
"As his first target grew larger and larger in his sights, Olds placed his finger on the trigger of his four .50-caliber machine guns, ready to squirt a stream of lead into the cockpit of the 109. Suddenly, his engines (P-38) sputtered and quit. In all the excitement, he had forgotten to switch fuel tanks and his engines had run dry. Without taking his eyes off the target, he switched tanks. The engines erupted and came back to life and Olds took his shot. 'I don't know if anyon ever shot down an enemy aircraft while on a glide slope, but I did. I fired and he sparkled with hits, smoked, dove off on his right wing and promptly bailed out.' "
pg 9, "Fast Movers."
