tcj wrote:

whynotfly wrote:On my commercial check ride the examiner (who had forgotten more about flying than I will ever learn) asked me during the oral portion "what causes a plane to stall?" If I gave an answer other than "uncoordinated flight" I would have failed the oral.

I would have failed with my answer to that question. Can you elaborate?

Uncoordinated flight + stall = spin last time I tried it... I too don't understand this concept.

I would have failed as well. The pilot pulling back on the stick causes the stall, either while aileron and rudder are coordinated or uncoordinated. The uncoordination is what causes the spin after the stall.

I would have failed too. Maybe I don't catch the context of the question. I can assure you though, uncoordinated flight is not a pre-requisite for a stall. Turn to final spin maybe, but not stall.

So, if I was asked...

"what causes a plane to stall?"

And I say "insufficient air flow over the wing" do I fail?

Experimental Aviator,

No, but your orientation is askew. Your answer and exceed the critical angle of attack are right, but both seem to blame the airplane. For greater safety, we instructors need to emphasize how the airplane is trying to help us not hurt us. It is designed so that if we pitch up, it drops its nose. If we bank, it drops its nose. If we reduce power, it drops its nose. If we stall it and turn loose, it will usually recover by itself. If we spin and turn loose, it will usually recover by itself.

If we turn at whatever bank is necessary to get the nose around and onto the target, the numbers, it will drop its nose. It will not stall. It will not spin The pilot has to do that by pulling back. Why would we want to pull back? We need to go down to land.

The airplane can be stalled, by the pilot, in any attitude. The airplane cannot stall itself. The safe thing for the pilot to do, in the turn to final, is to bank as necessary to turn to target and let the nose go down naturally. Once the wing is again level, on final, any pitch adjustment can be made.

Bad orientation is not the pilot's fault or the instructor's fault. It is the fault of the training system. It is a systematic problem.

whynotfly wrote:On my commercial check ride the examiner (who had forgotten more about flying than I will ever learn) asked me during the oral portion "what causes a plane to stall?" If I gave an answer other than "uncoordinated flight" I would have failed the oral.

Well, at the risk of sounding like a know-it-all, I think that's ridiculous, and the DPE is wrong, if that's the exact question and his required answer. The answer has to be the pilot who intentionally or unintentionally causes the wing's chord to exceed the angle of attack vs. the relative wind that it needs to keep flying. Coordinated or uncoordinated has nothing to do with it. As we were all taught in our early training, a wing can be stalled at any airspeed and in any pitch; but if it exceeds that angle of attack (typically about 18 degrees on current trainers), it will stall--but it won't do it by itself under most circumstances, as it needs pilot input to cause it to do that.

Cary

Cary wrote:

whynotfly wrote:On my commercial check ride the examiner (who had forgotten more about flying than I will ever learn) asked me during the oral portion "what causes a plane to stall?" If I gave an answer other than "uncoordinated flight" I would have failed the oral.

Well, at the risk of sounding like a know-it-all, I think that's ridiculous, and the DPE is wrong, if that's the exact question and his required answer. The answer has to be the pilot who intentionally or unintentionally causes the wing's chord to exceed the angle of attack vs. the relative wind that it needs to keep flying. Coordinated or uncoordinated has nothing to do with it. As we were all taught in our early training, a wing can be stalled at any airspeed and in any pitch; but if it exceeds that angle of attack (typically about 18 degrees on current trainers), it will stall--but it won't do it by itself under most circumstances, as it needs pilot input to cause it to do that.

Cary

In his (DPE) defense he may have been asking about "spins". But I do recall being surprised at the question/answer and I remember my primary instructor warning me about the question I would be asked, cuz I probbaly would have answered differently too. If I have a chance I think I will ask him about it again. This was some years ago. He is a quite elderly ex-Vietnam fighter jock who seems to be intent on becoming the oldest ever acting DPE.

The oldest ever DPE, I think, is Sam Dyer (Dyer the Flyer on his Ag business card years ago.) He is in his ninetys. How do you think my students ever passed a flight test making more than thirty degree banks.

There are examiners who test to see if you know how to fly. They can work around some of the pluses and minuses if you can fly. Sam was testing pilots before there was a PTS.