Picking up a stalled wing with full rudder no aileron.

[Judd]

Chatting to a bunch of PPL's at an aero club bar the other day when the subject came around to stall recovery technique taught by their various instructors.

Each one said their instructor had told them to never use ailerons to level the wings if one wing happened to drop at the point of stall but instead to apply full rudder to cause the dropped wing to skid in the direction of rudder and so pick up lift which automatically levelled the wings without using aileron.

Where does this strange theory come from? An old war story perhaps? I would have thought that full rudder to "pick up" a dropped wing at the stall would have the potential to lead into an incipient spin in the direction of full rudder?

[Whopity]

This dates back to the 60s/70 where some FIC instructors may have learned on the Harvard. At a FIE Seminar some years ago, it was stated that top rudder was used to minimize height loss in the recovery on that aircraft. The CAA has been trying to stamp this out for years but old habits die hard.

[sapperkenno]

Teaching in the UK, my "local" examiner has said he would fail people, if during their approach into, and recovery from a clean stall, they use any aileron without first reducing AoA... I'm slightly at loggerheads, as I am more than happy with people using co-ordinated aileron/rudder to keep the wings level (or at any other bank angle they require them), then when they want to recover from the stalled condition, reducing AoA. Surely that's why we have washout on our wings, so the root stalls first due to it's higher incidence, and ailerons continue to work happily - I've also never been able to stall the wing I'm trying to lift first (WHILE STAYING CO-ORDINATED), yet the books tell me this should/could happen as I'm increasing it's AoA further, and it will bite me and flick the wrong way. This in a variety of types through PA18, 2T-1A-2, T67M, PA28 and Cessna 150/152... Perhaps I'm missing something?!

[Cows getting bigger]

The examination requirement is that aileron should not be used to lift/arrest a dropped wing during a stall. It is acceptable to use rudder to arrest a dropping wing but not to lift it. The whole rationale is that the prime action should be reduction of AOA; remember we're trying to teach an automatic response to an unplanned manoeuvre in a wide variety of aircraft types. Indeed, in theory the same technique could be used on anything from a Cessna to a Boeing.

[Big Pistons Forever]

The automatic response for ab initio stall recovery instruction has to be stick forward. Reducing AOA is the immediate priority, as the student is doing that rudder can be used to stop any developing yaw, full power is then applied and with the airspeed increasing co-ordinated aileron and rudder used to level the aircraft and then the aircraft is pitched up.

The big thing that has changed is emphasis on minimum loss of altitude has been dropped. This IMO is sensible move as getting the airplane flying again has to be the first priority and trying to hold the nose up and power your way out of a stall is a recipe for disaster. Even simple airplanes will bite if abused this way

I once had a flight where the student (not mine) who was proud of how little altitude he could lose in the 150 after the stall. He made an aggressive pitch up to a power on stall and then when it stalled held the nose up and applied full power. The aircraft did a very nice half snap and flipped inverted at which point he screamed "you have control" :rolleyes:

[mykul10]

Use rudder to prevent further yaw......

[BEagle]

Rudder should only used to maintain balance during stall recovery....

This 'picking up a wing with rudder' nonsense should have been binned at least 40 years ago....:(

[Genghis the Engineer]

Hear hear Beagle. Neither roll nor yaw are inherently dangerous - sideslip is dangerous at high AoA, that's all.

Picking up a wing at-all is nonsense INITIALLY. Once an aeroplane is unstalled and under control, it's then the time to worry about any bank angle - not before.

G

[sheppey]

Teaching in the UK, my "local" examiner has said he would fail people, if during their approach into, and recovery from a clean stall, they use any aileron without first reducing AoA

Many Examiners only regurgitate their own theories presenting them as facts. Have witnessed that hundreds of times in my career. I ran a straw poll many years ago, asking students and flying instructors in various Australian States on what they had been taught re the subject of "picking up the wing with rudder" at the point of stall. What had me dismayed was that upwards of 90 percent of replies indicated that is what they had been taught. And still are at many Australian flying schools. It seems unstoppable despite the correct method being published in the CASA Flight Instructor Training Manual.

[eckhard]

It seems unstoppable despite the correct method being published in the CASA Flight Instructor Training Manual.

Any chance you could let us know what the CASA method is please?

[athonite]

This term 'using rudder to pick up a wing' has been going on for years it really iritating just as to 'kicking the rudder'. It really down to poor instructional use of language and a lack of understanding of the misuse of rudder and the consequences.

I have alway used 'smothly apply rudder to prevent further wingdrop' as part of the stall recovery sequence in relation to the AoA, it's alway better to follow the POH as to the sequence, likewise follow POH on the spin revovery sequence technique to the book.

[Genghis the Engineer]

Applying rudder to keep the aircraft balanced is not quite the same as applying rudder to reduce further wing drop.

The latter, I would argue, is another made-up variation on picking up the wing, and also wrong.

G

[athonite]

If im apply rudder, to prefent further wing drop, would I not be putting the aircraft in balance, very different to raising the stalling wing with rudder?

[BEagle]

No you wouldn't be....:rolleyes:

Please stop teaching incorrect and potentially dangerous practices!

[athonite]

Why, please enlighten me!

[Big Pistons Forever]

Rudders primary effect is yaw control. The secondary effect of yaw is roll. Trying to use this effect to "pick up the wing" is IMHO just silly, not the least because you would have to remained stalled for this effect to kick in and I can think of no situation where you would not want to recover immediately in the event of an unintentional stall.

Bottom line wheel forward to reduce AOA ( NOTE: we are taking Ab inito training here, not upsets in swept wing fighters :rolleyes: )
When you are doing this use the rudder as appropriate to stop any yaw and when the aircraft is flying again use co-ordinated ailerons and rudder to level the wings.

BTW I do the falling leaf exercise with every PPL student. Do a power off stall and when the aircraft stalls keep full back stick on. The aircraft will try to yaw and roll into the spin entry but prompt use of the rudder to counter the yaw will stop the aircraft from departing controlled flight. It is IMO an excellent demonstration of the ability for you to use all the available controls to make the aircraft do what you want.

[sheppey]

Any chance you could let us know what the CASA method is please?

The CASA Flight Instructor Manual states: "Use the standard recovery, i.e 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."

[captainsmiffy]

The use of rudder was never intended to 'pick up a wing' at the stall....rather, it was meant to prevent further yaw. A stall condition plus yaw was a potential recipe for a spin entry. Thus stall recovery, as taught in the Royal Air Force, was stick forward to unstall the wings whilst simultaneously increasing power and rudder used, if neccessary, to prevent further yaw. That is all. No mention whatsoever, of picking a wing up.

Use of aileron to pick the wing up runs the risk of further stalling that portion of the wing around the aileron and was verboten!!

[Genghis the Engineer]

At the stall we have a high AoA - this creates a risk of secondary loss of control, and also high drag - which bleeds energy off and causes a high rate of descent.

We wish to do two things initially - ensure that there is no secondary loss of control (most important) and reduce height loss (a bit less important).

So we move the stick forward and simultaneously (UK, EASAland, Australia) or just after (FAAland) apply full power. The stick reduces AoA, the power reduces height loss by putting more energy into the aeroplane.

Whilst the aeroplane is at high AoA, we want to avoid two things - (1) sideslip, (2) any further pitch up.

(2) Is ensured by not applying power before the pitch input, as in most aeroplanes there is a nose-up pitching moment with increased thrust. Yes, I know we hadn't mentioned that before, I'm just including it for completeness and before anybody starts talking about the equally henous practice of powering out of the stall.

(1) - sideslip, is avoided by using the rudder to keep the aeroplane in balance. Depending upon what you've got in the particular aeroplane - a yaw string (gliders mostly), beta gauge (a few hi-tech aeroplanes), slip ball (most aeroplanes) or sense through the seat of pants (anything) will all tell you whether the aeroplane is in balance. In very simple, but correct terms, an in-balance aeroplane has no sideslip.

However rapid the stall entry is, however much wing drop you have, whatever other motion is going on - if there's no sideslip, there should be no secondary loss of control (most likely an incipient spin).

The reason for not using aileron is exactly the same - any use of aileron will cause some sideslip. The design of the aeroplane will change the maginitude and sign of that, but is near certain not to eliminate it. So we keep the ailerons neutral.

If you do anything whatsoever with the rudder apart from keeping the aeroplane in balance, then there will probably be non-zero sideslip. If you do anything with the ailerons apart from keep them neutral, there'll be sideslip. With non-zero sideslip, there is a risk of 2LOC, and thus risk of a spin.

It doesn't matter whether you try to pick up a wing, prevent further wing drop, prevent further yaw - call it what you like; ANY use of rudder apart from to keep the aircraft in balance, is likely to result in non-zero sideslip, and thus a non-zero risk of a spin.

(Which is pretty much what BEagle said, just I used more words).

G

[Centaurus]

Very well explained Ghengis. That should be framed and displayed in every flying school briefing room.
I first met up with wing drops at the stall when learning to fly the RAAF Wirraway trainer. A whole bunch of trainee pilots straight from Tiger Moths were bussed in to Uranquinty NSW to commence basic flying training. As the base had just been re-opened after the war, aircraft and instructors were still arriving and setting up. Our bus stopped at the aerodrome perimeter to allow us trainees to watch our future steeds arriving en masse.

One Wirraway passed directly over the top of us and lo and behold the pilot (who was a Warrant Officer instructor) held off too high and floated over the grass field. It looked like a beaut three-pointer was about to be made when one wing dropped sharply and the wing tip bashed the ground.

We had seen our first dreaded wing drop of a Wirraway which was notorious for such a thing. Talk about a picture being worth a thousand words. Apart from the universal exclamation of '****" from we 30 trainees in the bus, there was a moments silence and we could see all the rumours of Wirraway wing drop tendency was true.

Yet the stall recovery technique as explained by Ghengis in his post was taught to us then and remains true to this day. Never did we hear the term "pick up the dropped wing with rudder." However our instructors did demonstrate that instinctive application of instant aileron to pick up a dropped wing at the point of stall, usually resulted in that wing dropping more sharply and into an incipient spin in the Wirraway.

A generalisation I know, but it was said by our instructors in those days that if you could fly a Wirraway safely you could fly anything.
There was a grain of truth in that claim since many of us went directly to Mustangs and even huge Lincoln bombers straight from Wirraways without bending anything. It was considered no big deal at the time.

[Dan Winterland]

Genghis explained it technically. Captainsmiffy explained it in pilotspeak. BEagle has applied the correct emphasis. No further explanations are required.

[formationdriver]

Spin exit: simultaneous power off, neutral ailerons, full rudder toward the wing in the blue, or gray (foot in the sky) + forward stick. When the sight picture is 'normal," i.e. the world stops spinning on the other side of the windscreen, rudder back to neutral, gentle pull to bring the nose up to the horizon (not too roughly or the plane will re-stall) and power as needed. Works just fine in everything form C-152 to CAP10, Pitts S2B, SF-260, 8KCAB,T-6, PT-17 and Extra 300. Accueil | CAPTENS (http://www.captens.fr)

[Level Attitude]

the world stops spinning on the other side of the windscreen, rudder back to neutral, gentle pull to bring the nose up to the horizonFor completeness I think you may want to add in an extra step otherwise you may well often be practising spiral dive recoveries.

[Genghis the Engineer]

So long as you don't get the rate of forward travel wrong, use that drill in.some Jodels which require back stick, nor in some microlights which use a controls central recovery as the powerful cruciform rudder may push you into a spin in the opposite direction.

I'm a fan of standard stall recoveries, but in my experience - which includes running the spinning trials on several new types - spin recoveries are often type specific and the POH matters.

G

[BEagle]

There is NO SUCH THING as a 'Standard' spin recovery.

Although AoA and yaw must be reduced, the sequence and timing of control movement is indeed type-specific.

[Centaurus]

There is NO SUCH THING as a 'Standard' spin recovery.


Yes and no. But you have to start somewhere and as such the "standard" spin recovery was taught to RAF trainee pilots (and other Commonwealth military services) before the start of WW2 and continued. A glance through many of the Pilots Notes published by the RAF for example and used by Australian, Canadian, and New Zealand Air Forces in those times, reveals variations of the theme.

The single seat Vampire PN makes no mention of how to recover from a spin.
The DH Mosquito PN says "Intentional spinning is not permitted. An incipient spin should be checked immediately by normal recovery action".
Sea Fury. No mentioned of spinning.

Auster PN. Several paragraphs on spinning including the statement for recovery : "Apply full opposite rudder. Pause at least one second. Move the stick progressively forward until rotation ceases. Centralise the controls immediately. Pull out of resultant dive".

Hawker Hurricane. Spinning of Mk.2D and Mk 4 aircraft I prohibited at all times. On Mk 2A, Band C aircraft, spinning is prohibited when carrying 90 gallon drop tanks, bombs or RP. Recovery is normal but the loss of height involved in recovery is very great. Recovery is to be initiated before two turns are completed.

Mustang. There are several paragraphs on spinning. The opening paragraph states: "Practice spins are not to be started below 12,000 feet and the engine is to be throttled back before starting the spin. Recovery action is to be taken after not more than two turns. The average loss in height in turns left or right and in recovery is about 3000- 3500 feet"

The rest of the paragraphs on Mustang spinning is positively frightening such as the advice that if a power-on spin occurs as many as five or six turns may be made after recovery action and 9000-10,000 feet lost.

PS Dear Beagle. No real need to "Shout" in your Post No 25, old chap..

[Genghis the Engineer]

I rather approve of BEAGLE shouting. The desire for a universal spin recovery, far too often translates into people believing it's real. Whilst the differences can be small and subtle - they matter.

Taking one example already mentioned, when I tested the the Auster 5L for LAA when the type moved from CofA to PtF, I checked the "SSR" of immediate forward stick as well as the POH version. The POH version is fine, but immediate forward stick caused substantial negative G. Fine for a Test Pilot in a hard helmet, specially tightened straps and ready for anything - but somebody in an inadvertent spin? Similarly, when I ran the X'Air spinning trial, we showed that the SSR required identification of the spin direction by a pilot, which they weren't trained to do, and also the powerful rudder could kick the aeroplane into a spin in the opposite direction. Hence the controls central recovery, common on many microlights including the X'Air, Thruster, SkyRanger...

So, I am shouting alongside BEagle I'm afraid.

G

[212man]

The reason for not using aileron is exactly the same - any use of aileron will cause some sideslip
I was under the impression that the use of aileron will move the stalled section of the wing outboard, as the AoA is increased.

[Genghis the Engineer]

Can't say that I have ever seen that anywhere I would consider authoritative.

G

[212man]

My recollection came from UAS days, but some discussion on it here (NZ CAA website): https://www.caa.govt.nz/fig/advanced-manoeuvres/wing-drop-stalling.html

By using aileron to stop the roll (a natural tendency), the mean angle of attack increases on the down-going wing. The lift continues to decrease with an increase in angle of attack (past the critical angle), while the drag continues to increase rapidly with any small increase in angle of attack. Show the effect of aileron on the CL and CD curves on the graph.

The use of aileron adversely affects the roll and favours autorotation. This is the reason for maintaining ailerons neutral in the initial stall recovery.

[Genghis the Engineer]

That says roughly what I had. Nothing about changing alpha_max. Also not really authoritative regardless.

G

[fireflybob]

So we move the stick forward and simultaneously (UK, EASAland, Australia) or just after (FAAland) apply full power.

Genghis, nice post thanks but I was under the impression that EASAland was now stick (centrally forward) first and then select full power rather than simultaneous?

[Genghis the Engineer]

If they have, the docs have passed me by. Can you provide a reference?

Cheers,

G

[sapperkenno]

any use of aileron will cause some sideslip
My brain is starting to hurt a little now, but would co-ordinated rudder not negate/minimise this? Or are we saying that rolling an aircraft creates sideslip..? Or that an aircraft at any bank angle (even if co-ordinated) is slipping? If so, how? Not trying to be flippant, but just increase my level of understanding! Thanks in advance for any answers.

I also seem to recall an EASA/CAA document doing the rounds a couple of years ago re: reducing AoA, then increasing power, as opposed to "powering out". Will try find reference.

[Genghis the Engineer]

Yes - every time we fly a co-ordinated turn, we are using the rudder to remove sideslip created by aileron deflection.

I certainlyremember the documents slating powering out of the stall, but I don't recall their promoting a switch to the FAA stall recovery.

Relevant...
http://aerosociety.com/News/Publications/Aero-Journal/Online/2190/Evaluating-a-set-of-stall-recovery-actions-for-single-engine-light-aeroplanes

G

[Centaurus]

For years I thought the idea of applying power at the same time as lowering the nose during stall recovery was to give immediate increase in slipstream over the various lifting surface and thus give more lift - thereby recovering from the stall. Prop aircraft only, of course. Have I got it wrong over all these years?

One way or another the aim is to recover from a stall. Lower the angle of attack (stick forward) and power simultaneously does just that. Jets are different. Increase thrust while simultaneously lowering the nose a few degrees to the horizon or just below, should increases speed hopefully and thus recovery from a stall should occur.

High altitude stall recovery is a bit different. You need to count on losing 3-4000 feet while deliberately picking up to a safe manoeuvering speed. Important to keep the aircraft accelerating downhill in this case to avoid secondary stall symptoms caused by nose wanting to rise with increasing IAS.

The Boeing 737 FCTM gives a good hint on defining "safe speed" before level flight is started. Vref 40 plus 100 knots. Typically around 210-230 knots IAS before levelling out or even attain severe turbulence speed before attempting to level out if the cause of the problem in the first place was severe turbulence penetration followed by an upset in IMC

[Genghis the Engineer]

For years I thought the idea of applying power at the same time as lowering the nose during stall recovery was to give immediate increase in slipstream over the various lifting surface and thus give more lift - thereby recovering from the stall. Prop aircraft only, of course. Have I got it wrong over all these years?

In my opinion, yes. More thrust is almost entirely about putting more energy into the system to reduce height loss.



Jets are different. Increase thrust while simultaneously lowering the nose a few degrees to the horizon or just below, should increases speed hopefully and thus recovery from a stall should occur.

In my opinion, that makes jets the same.

When we compared notes at the SETP symposium in Madrid 3 years ago between the GA researchers who wrote the paper I linked, and the joint Boeing / Airbus team presenting on large aircraft stalling - it seemed to me that the only real differences were of numbers - big jets take longer to do everything and lose far more altitude, but the handling and reasons for doing things really don't change.

G

[PDR1]

In my opinion, that makes jets the same.



Except that you may not wish to "unsettle" a jet engine with a throttle movement once in a spin. If the engine keeps running with the strange flow conditions it's more likely to continue running if left stable, and far more likely to flame out if accelerating or decelerating.

PDR

[Genghis the Engineer]

That's a spin, not a stall and stall recovery. In my opinion, we should probably not jump back and forth between them quite so much in the same discussion? Whilst related, they aren't the same topic, and I certainly wasn't referring to the developed spin when I said that.

G

[Dan Winterland]

And the Hamster wheel turns full circle! It seems the notion of the "Standard Spin Recovery" reappears regularly on this forum every two years. There was one once , as someone points out. This is from WW2, when everything from instrument panels, checklists and recovery drills were standard. And in the wartime days of needing flexibility between types, it worked well. It was the introduction of the Chipmunk, for which the standard spin recovery didn't work so well, killing a few people (less acceptable in peacetime) that led to an adaptation. And it turned out that the standard didn't work for many other aircraft as well. The good advice is to apply the recovery for your type as described in the POH. And there are some really large variations. For example, the Cirrus SR22 requires you to immediately deploy the ballistic recovery system and the Jaguar required you to centralise the controls, if not recovered by 10,000ft - eject! there are so many factors, aerodynamic, power and inertial considerations that you really need to be aware of your type's recovery technique.

And now, there's no standard stall recovery. Experience has shown that low slung engines coupled with nose up stab trim impedes the recovery in modern jet transports, so we now have type specific recoveries. In the A320, we lower the nose, level the wings, ensure speed-brakes are retracted, select Flap one if clean, and only when the aircraft is out of the stall, apply power. This is fresh in my memory as I was practicing them in the sim 2 days ago. And it is very hard to forget 30 years of using a previous drill and applying power immediately.

[BigEndBob]

Ever driven a car too fast and skidded and think, I won't do that again.
Most pilots I check out are scarred of stalls never mind spins.
Yet thousands of them manage to survive their daily flights.

[sapperkenno]

Yet thousands of them manage to survive their daily flights.
Which is a valid point... Can anyone remember the last time they had to recover from an unintentional stall? I certainly can't.

[BigEndBob]

Same as keeping aileron neutral approaching a stall.
First thing the average pilot does when the wing drops is apply aileron to roll wings level.
So if we teach stall recovery do some with aileron applied, because that's reality.
Only few occasions I got accidently at the stall and that was wing dropping to 70 odd degrees climbing out in really bad turbulence.
My gut instinct was opposite aileron and rudder and push to level..

[PDR1]

Which is a valid point... Can anyone remember the last time they had to recover from an unintentional stall? I certainly can't.

Can you remember the last time you used a life jacket? Yet if you fly over water you still carry one. Same's probably true of an ELB...

For me at least half the point of teaching stalls/spins in basic pilot training is to become familiar with that it feels like so you can recognise a stalling wing-drop as distinct from a simple bit of turbulent air, so that you might pause befre simply whacking the stick/yoke over to pick it up.

And of the remaining half I'd say 45% was simply to give pilots confidence that the aeroplane can do something like a stall and nothing breaks. So [IMHO] only 5% of the reason is to equip non-aerobatic pilots to recover from stalls/spins.

PDR

[fireflybob]

Can anyone remember the last time they had to recover from an unintentional stall? I certainly can't.

There have been quite a few people in aviation history who can't remember the last time they had to recover from an unintentional stall because they are no longer with us - go figure!

[Genghis the Engineer]

Yes, I can.

I fouled up the approach in an unfamiliar type, and it saved my life.

G

[Parson]

John Farley has written quite a lot on stalling. One thing he suggests is practising flying straight and level and tickling the power gradually back towards the stall (at height of course) to get used to flying just above the stall speed.

The aim of the exercise is to get comfortable flying approaches at the correct speed and not +5-10 knots 'just in case'.

[nick14]

I thought this had been irradicated?

What I think may be confusing some people is the difference between maintaining wings level balanced flight versus a dropped wing.

Wing drop = stall and therefore standard stall recovery which should always start with the nose down pitch control (ignore aerobatics). What you do with the controls after the wing is unstalled doesn't matter within reason, including on the jets (however we never use rudder inflight under normal ops).