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-   -   Wing drop recovery at the stall - killing an old myth. (https://www.pprune.org/pacific-general-aviation-questions/278350-wing-drop-recovery-stall-killing-old-myth.html)

A37575 1st Jun 2007 12:15

Wing drop recovery at the stall - killing an old myth.
 
An instructor at Moorabbin mentioned that the standard wing drop at the stall recovery technique taught at GFS was that the student locks the ailerons central at the point of stall then picks up the dropped wing by applying rudder with sufficient force and duration to skid the aircraft into level flight. Only when the wings are levelled in this manner is the student taught to relax and use ailerons in the conventional sense.
This myth is still perpetuated from decades ago where the instructor course teaching was to "pick up a dropped wing with rudder." It is surprising that a well established flying school that prides itself on graduating pilots good enough to join Qantas, permits such a curious method of stall recovery from a wing drop. Certainly all the flying training books currently on the market and in past times have never recommended this technique of forced skidding at low speed. The technique published in most reputable flying training manuals requires the pilot to use sufficient rudder to prevent the wing drop from increasing while simultaneously applying forward stick to break the stall and applying aileron at the same instant to level the wings. The same technique applies to just about every aircraft type.

404 Titan 1st Jun 2007 12:51

A37575

The same technique applies to just about every aircraft type.
Do that in a swept wing aircraft and it may kill you. I'm sure though you already knew that?:ok:

The technique published in most reputable flying training manuals requires the pilot to use sufficient rudder to prevent the wing drop from increasing while simultaneously applying forward stick to break the stall and applying aileron at the same instant to level the wings.
Just as a slight correction to your wording. In an unswept winged aircraft aileron should only be applied once the angle of attack has been reduced below the critical angle and not simultaneously with other control inputs as you have suggested. This comes from many years of demonstrating to advanced students the dangers of using aileron just as you have advised. Let me assure you in almost all occasions it will bight you. Now having said that aileron can safely be applied about one second after you have initiated a stall recovery by simultaneously using rudder to stop any yaw and relaxing the back pressure to reduce the angle of attack.

787 Captain 1st Jun 2007 12:54

The technique has worked well for me whenever I have used it. I think the idea of it is mainly for inexperienced pilots, so that they can focus on one thing at a time and ensure a recovery isn't botched, at least too much! Basically, inexperienced pilots often seem to be more distracted by the rotation, and the longer it takes them to stop this, the faster the rotation becomes. I believe the expectation at GFS is that as you become more experienced, you will apply some forward pressure when appropriate, rather than waiting for rotation to stop. But at GFPT level, it seems like a pretty safe method that can't really get screwed up to much.
At least that's my take on it.

787

Lefthanded_Rock_Thrower 1st Jun 2007 13:29

Works fine for me also.

Have you ever tried it ?, its not a stall recovery method from a spin, its more of a technique to avoid stalling into a spin.

Go up to a safe height and try it with power off, with most hi-lift wings ( even a C150 ) you'll be doing well to actually stall the aircraft with this technique ( power off, full back stick and maintain directional control with the rudder ).

If you try it in an aircraft with more laminar wing, do it with even more altitude just incase.

Swept or delt wing, not a good idea.

787 Captain 1st Jun 2007 14:23

GFS also uses this method for teaching spin recovery. It seems to work well enough, as with full opposite rudder rotation can be stopped in 90 degrees, after first entering a spin and maintaining it for two and a half rotations. Then apply a bit of forward pressure and you're good. It's certainly a bit quicker to recover if you get some forward pressure in there before the rotation has stopped, but it if works for you and you're comfortable with it then you may as well do it.

newagebird 1st Jun 2007 14:31

Been using the technique for a while and never had a problem. Im no instructor but theres no point using aileron at all since it would be ineffective in stall (turbulent air). However once past the critical angle control effectiveness improves allowing the use of aileron as 404 titan said.

cheers

Tee Emm 1st Jun 2007 14:34


I think the idea of it is mainly for inexperienced pilots, so that they can focus on one thing at a time
Not a valid argument at all. Providing the instructor is capable of demonstrating the correct technique (and some instructors have problems in this regard) the student should be able to replicate the manoevre after competent instructing. The student should not be certified competent to go solo until he has demonstrated the correct stall recovery. Deliberately teaching a flawed technique such as skidding the dropped wing in order to attain wings level, is not the way to instruct.

404 Titan 1st Jun 2007 14:44

787 Captain

Just a word of caution. Full opposite rudder (not all aircraft require it and in some it may make things worse) without simultaneously relaxing the backpressure will only result in a spin developing in the opposite direction. You must reduce the AoA below the Critical angle with elevator and stop the yaw with rudder at the same time to effectively stop the spin.

Centaurus 1st Jun 2007 14:53

Extract from the Department of Transport Flight Instructors Manual DoT 2342 (rev 9/1975) - and nothing in terms of technique has changed since then:
Exercise 9 - Stalling - Recovery when the Wing Drops:
"Use the standard recovery - simultaneous use of power and forward movement of the control column. In addition rudder must be used to prevent the nose of the aeroplane yawing into the direction of the lowered wing
The ailerons should be held neutral until control is regained, when the wings should be levelled. In aeroplanes where the ailerons remain effective beyond the critical angle, they may be used to regain or maintain lateral level in association with the rudder".

Clearly control is gained as soon as the stall is broken which is usually instantaneous with forward stick. Thus ailerons are then used as normal to level the wings. Note the manual states that forward movement of the control column is used. In some instances merely relaxing back pressure on the control column may be insufficient to unstall the wings and thus delay recovery..
Interestingly, there is no mention of using rudder to pick up a dropped wing. Apart from Tiger Moths and Chipmunks of the 1940-50 era, it is my understanding that the Piper and Cessna series of singles and twins are designed so that their ailerons are effective beyond the critical angle. Not sure of the certification requirements in this regard for modern types such as the Cirrus.

ALLICEDUP 1st Jun 2007 15:34

If you are so concerned
 
Hey A37575,

If you are so concerned about this matter why dont you call GFS and talk to the CFI. Would this be the smart and sensible way to deal with a concern instead of trying to make yourself look smart on here and drop names of schools/companies that you have a problem with. I a sure that you are perfect and can correct everyone.

My last job involved training new recruits to a GA company and I could not believe the standard of pilots in GA in general. These pilots came from many different backgrounds and flying schools. So please dont poke fingers, go to the source and they may appreciate that.

Sorry if I have gone on and on, but enough is enough, I would love to meet half the fools on here, sure that would be a laugh!

787 Captain 1st Jun 2007 15:48

"Full opposite rudder (not all aircraft require it and in some it may make things worse) without simultaneously relaxing the backpressure will only result in a spin developing in the opposite direction."

It's true what you say, but I haven't found a spin in the opposite direction a problem, because if you are proactive you ease off the rudder at the right time so that your rotation stops completely. I found that the technique worked well overall, but I certainly now prefer relaxing backpressure or maybe applying some slight forward pressure before rotation has stopped. As far as full opposite rudder is concerned, sorry, I was thinking of spin recovery in a particular aircraft type at the time. You're right, if you apply full opposite rudder for a small wingdrop you'd go back the other way.

"Not a valid argument at all."

That's hardly the case. When stalls are first being taught, it is easy to maintain control of the aircraft by keeping the aircraft in balance as it approaches the stall, and then if there is a wingdrop apply opposite rudder to stop rotation and then relax the backpressure to break the stall. I personally relax back pressure before rotation has stopped, but if you are more comfortable with stopping the rotation first then you may as well do it. Remember that there are a number of people, particularly inexperienced pilots, who get nervous with stalls, so sometimes keeping it simple can keep the stress down. I don't believe that having a firm stance again this technique will solve the problem. If it works, then this 'flawed technique' isn't really all that bad is it? I'm sure the CFI of GFS has a good reason for teaching this technique.

Wizofoz 1st Jun 2007 17:11


Just a word of caution. Full opposite rudder (not all aircraft require it and in some it may make things worse) without simultaneously relaxing the backpressure will only result in a spin developing in the opposite direction. You must reduce the AoA below the Critical angle with elevator and stop the yaw with rudder at the same time to effectively stop the spin.
COMPLETELY disagree-

Standard spin recovery-

1) Opposite rudder until rotation stops

2) Relax back pressure

3) Recover from the dive.

In a high performance aircraft, what you advocate is a recipie for the "Dead mans spin"- that is, forward pressure simutainious with opposite rudder has the potential to put the aircraft in an INVERTED spin in the opposite direction.

The danger of this is that an inverted spin in one direction is very hard to distiguish from an upright spin in the other. It is extremely disorientating as it appears that the aircraft has simply not responded.

The first aircraft I ever owned was a Pitts S2A. A subsequent owner was extremely lucky not to die after crashing through trees after a very low recovery due to exactley what I have described above.

Tinstaafl 1st Jun 2007 19:59

Bravo Centaurus! That's what I taught (when I used to teach) - the goal was to stop the yaw by using rudder while reducing AoA by using elevator. In essence the concept was that they were two separate problems albiet with the same root cause, with two individual 'solutions'.

Once the aeroplane was flying again *then* use aileron to restore wings level flight. Until then it was a waiting game until the control inputs worked.

I also taught that if yaw couldn't be controlled while stalled then spin recovery technique should be used.

YesTAM 1st Jun 2007 21:14

C150 will drop a wing if you look at it. C172 less so. The demonstration of a spin in a C150 almost turned me off flying for good. I can still here the thump of the instructors foot on the rudder pedal.

jbr76 1st Jun 2007 22:19


C150 will drop a wing if you look at it. C172 less so.
The Cessnas will only encounter a wing drop *after* a power on, full flap stall. I have never encountered any wing drop on either c152 or c172 with zero flap & power off. :8

The only other aircraft I ever flew that had a nasty wingdrop in a clean configuration was a piper traumahawk .. guaranteed they dropped a wing every single time clean :E

404 Titan 2nd Jun 2007 00:38

Wizofoz

You won’t get an argument from me about using that that technique with “Standard Spin Recovery” however I was talking about ”standard Stall Recovery” as that’s what the post is about. Probably in the post you refer I should have said “to stop it developing into a spin”.

jbr76

As Centaurus has said most Cessna/Piper singles the ailerons work perfectly OK right up to and during the stall as it is generally only the wing root that has exceeded the critical angle at the “stall”. Having said that though, using aileron can cause in a Cessna and will cause in some other aircraft an undesirable roll opposite to that requested resulting ultimately in a spin.

Cessna singles probably have the most benign stall characteristics of all the singles I have flown. It is true to say that trying to get a wing to drop can be difficult though apart from the obvious full flap and approach power you can get a wing to drop quite nicely in a full power climbing turn.

ILS 31R 2nd Jun 2007 01:08

I did my first stalls in a C150 with 30 degrees flaps and 1500 rpm and definately gives you a great wing drop.
I was taught that once the wing drop has occurred opposite rudder to wing drop, power to idle,let the airspeed build up to about 60 kts then raise the nose and apply full throttle with forward pressure and raise flaps in 10 degree stages and trim etc,i've probably missed something out.
You can really get some nasty wing drops in a C150.:eek:

MACH082 2nd Jun 2007 01:24

You are using rudder to prevent further yaw not to level the wings or slip the aircraft!

remember the patter!

Theres the stall
Full Power
Prevent further yaw with rudder
Speed Increasing
Wings Level
Nose on the Horizon
Regain Lost height

The reason for not using aileron at the point of stall is generally a C152 (in this example) will drop a left wing. If you try and pick the left wing up with aileron you will further increase the AOA on the downgoing wing deepening the stall and maybe entering an incipient spin. At this stage in the students training you have not taught spin recovery, they will not be flying solo in the training area for a while yet as they have many moons of circuits ahead of them!

That is proven fact and training will continue in this manner no matter how much you whinge on prune.

MACH082 2nd Jun 2007 01:30


Cessna singles probably have the most benign stall characteristics of all the singles I have flown. It is true to say that trying to get a wing to drop can be difficult though apart from the obvious full flap and approach power you can get a wing to drop quite nicely in a full power climbing turn.
Its very easy to get a wing drop in a Cessna, Use aileron for the wing you want to drop at the point of stall!

152's spin well, i have many fond memorys of spinning a 152 from 6000 to the 3000AGL minima.

Arm out the window 2nd Jun 2007 02:01

Well said, Mach082.
Rudder to prevent further yaw makes good sense to me, but it seems crazy to be booting in heaps of rudder at stall speed to pick a wing up.
The rudder's going in at the same time as power's going on and attitude is being selected to unstall the wings, and very quickly you're able to use aileron to level the wings rather than stuffing around trying to do it with rudder.
Obviously there's a few viewpoints on the subject, but what you said is exactly what I'd do and teach.


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