Brett_Henderson wrote on Jan 12^th, 2010 at 8:57am:



That makes you more than just a pilot, a good pilot.  Any monkey can follow procedures, but by having that understanding of the mechanics and physics of flight, you will be more able to handle abnormal situations.  As I've always heard, and said, a pilot's license is only a license to learn. 

Now back to the original post.  I also don't see why negative torque would be any more harmful to the engine than the same amount of positive torque.  Those engines are putting out over 1000 horsepower to the props, and should be able to handle at least some of that coming back, much like semi trucks using the engine brake.  But I do admit, my knowledge of those large, high power radials is slim.  I do know a couple of warbird pilots around here, perhaps next time I see them I will pose the question.

specter177 wrote on Jan 12^th, 2010 at 4:06pm:


That's the other discussion..  do you keep it squared as you climb ? What's your cruise setting for something like 8,000msl  (and your climb setting(s) getting there) ? How soon after takeoff do you go to 25/25 ?

Full power is relative..    ..  You lose an inch or so of MP  per  1000 ft, anyway. .. so if you plan on cruising much above 5000msl, you'll firewall the power for takeoff, and just leave it there.

I was just wondering if you continuousy lowered RMP as MP went down.. but is sounds like you do it similar to the way I do.. relatively high RPM, even as MP drops, for a climb.

At altitude is where a constant-speed prop starts earing it's keep. You're already dealing with lowered MP .. and with a fixed-pitch prop, you have to reduce MP even further, to keep the RPMs low.. whereas the constant-speed prop allows wide open throttle, with economical RPMs 

One other reason why there are limitations in how fast you can change throttle on turbocharged engines is that most aircraft engines do NOT have water cooled turbos. You kill the engine oil and destroy oil flow when the turbo cools down too fast. The same reason why most tuned Imprezas have turbo timers, that will pump oil and water for a few minutes after shutdown to keep the turbo bearings in good condition.

What also makes these things a bit complicated I think is that most American and European GA pilots don't fly radials that much. For Russian GA pilots these are the only thing they see when getting airborne, so it is quite possible that the whole handling thing is not in the basic 'how to fly' lists for European and US pilots anymore