Originally Posted by
bigflyingrob
Has anyone measured P effect?
....
So any real testing been done?
????
Is your question - 'is the effect material?' or 'does some one have a specific measured result for a particular set of circumstances?'
Have you started to fly (a single engine aicraft) yet?
The reason for the second question is that everyone who flies a single either knows the effect is real and material or has had some very exciting stall experiences !
If you are looking for a specific number then we need more details? However, if the question is how do aircraft designers measure the effect to confirm their calculations then hopefully one of the engineers will answer (though I suspect that they imperically confirm that the engine cant, vertical stab positioning and trim tab setting provide a neutral rudder in cruise and an acceptable rudder force at power on stall.