to get it over compression to start windmilling again needed a dive to about 140 kts,
Yes I have air started a 152 and remember being surprised at how far into the yellow arc I had to go to get the prop turning.
Originally Posted by
sycamore
If you wish to restart a `stopped` prop in flight,by diving,is it better to open the throttle fully,or keep it closed...?
That is an interesting question to ponder. After the above mentioned experience it occured to me that opening the throttle would have reduced the speed required to air start the thing - but I remain unsure as to the effect or advisability of such an action. With the engine stopped the MAP and cylinder pressure will be unaffected by the throttle position so I expect you will need the same airspeed to get the thing turning to begin with. As the prop starts to rotate I'm pretty sure the thing will turn over quicker with the throttle open. How much difference this makes I could not say.