You think wrong Bill. At least on my Mooney at idle doesn't come close
to the vacuum gauge reading in the green. This is with a new dry pump
too. I still doubt that a windmilling engine will keep the gyros spooled
up enough to run the AI and DG. Just my .02. YMMV

Jon Kraus
'79 Mooney 201
4443H @ TYQ

Bill Zaleski wrote:


You think wrong, Jon. Even at idle, most vacuum pumps produce enough
differential to keep rotors spinning satisfactorily.