Originally Posted by
kghjfg
good call, I should be more aware of that as well for that reason.
(Off to check the POH.)
I would have a look at the difference it makes - I doubt its more than a few seconds from a normal cruising altitude. Flying the aeroplane is crucial in the event of the failure of your only powerplant. I would be far more focussed on flying the aeroplane towards a sucessful landing site than anything else. You are likely to waste those few seconds you save trying to nail the 65kts you need for minimum sink with a stage of flap than you are just concentrating on flying the plane. If you want to get maximum glide performance try to slow down enough to stop the prop windmilling (if it still is). I soared a super cub in wave in Scotland once and stopping the prop gave an extra 250 fpm climb rate so that was fairly significant. It also rules out the random cough and short lived restart that will ruin your day if it happens at 100 feet...
On the subject of Vx and Vy.. I have heard so much rubbish talked about the difference between best rate and best angle of climb. If you are ever in the situation where climbing at Vx compared to Vy means you will miss an obstacle rather than hit it just go and have a cup of tea and consider the wisdom of taking off.. Its interesting from a techincal point of view and totally pointless from the point of view of conducting a sensible flight.