PPRuNe Forums - View Single Post - Instructors teaching full rudder to "pick up" dropped wing.
Old 4th Dec 2018, 07:28
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rich34glider
 
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Originally Posted by Centaurus
The full rudder thing was about the scenario where at the point of stall, a sharp wing drop occurs. It is widely taught (and I don't know why) that recovery in that situation is to keep ailerons strictly neutral and apply opposite rudder to skid the dropped wing level by causing it to move faster than the other wing and thus generates more lift. The theory (which is BS) being you level the wings while lowering the nose to unstall the wings and you never used any aileron.

The problem with that BS is at the very low speed the aircraft is at the point of normal stall, instant full rudder is guaranteed to flick the aircraft into an incipient spin. Especially if there is a slight delay in lowering the nose.

Certification of aircraft designed in the past 40 years or more (Cessna series etc) require the ailerons to be effective below the stall, whereas aircraft in the old days (pre-war, post war) some had vicious wing drops. Application of opposite aileron exacerbated the wing drop. The classic was the Wirraway single engine trainer where the aircraft could flick inverted in a high speed stall. Hence the general advice when flying those types, not to use instant aileron to level the wings. Instead use only sufficient rudder to prevent a dropped wing from going down further and after the stall is broken by lowering the nose, use ailerons in the normal manner to level the wings. The whole maneouvre, including applying full power to minimise height loss near the ground, should be accomplished normally inside no more than 3-5 seconds.

But from interviewing hundreds of GA pilots over many years, you would be amazed that the vast majority said they had been taught by their flying school instructors to level the wings by rudder only - meaning literally skidding the wings level. Commonly called picking up the wing with rudder. And that is as recent as just a few days ago talking to airline candidates at flying schools that specialise in training cadets for selected airlines.
So whoever is training general aviation flying instructors are pushing old myths..
Standard gliding full spin recovery technique is exactly this "BS" theory as you describe it - FULL opposite rudder, centralise ailerons, forward stick until the autorotation stops, centralise the rudder & then recover. With incipient spin recoveries we teach to relax the back pressure (effectively, forward stick again) and if there is a wing drop to correct it with opposite rudder as required. Even with full opposite rudder in a full spin recovery there is a significant delay before the autorotation stops, so using anything less than full rudder is just delaying the recovery and wasting altitude. There's no prop slipstream to help I know (even in idle) but why would any GA single be so different? I know the CT-4 used exactly the same recovery technique as I described with no issues ... it certainly never even came close to flicking into an opposite spin. I suppose if you just never centralised upon recovery it might.
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