Instructors teaching full rudder to "pick up" dropped wing.

[Lead Balloon]

positively reduce angle of attach

I think they meant "actively reduce angle of attack".

[Clare Prop]

Cut and pasted so for once the typo isn't mine!

[oggers]

Serious 'mushing' with Capt Barry Schiff

[Virtually There]

Never taught to use "full rudder", except to enter and recover from a fully developed spin. What we did practice was using rudder to prevent a wing drop/yaw at the critical angle of attack. Ie; climb to appropriate height, reduce power, stick neutral/full aft and then dance on the rudders to keep the wings level in the stall as the aircraft rapidly lost altitude. Unload stick to break the stall and recover - all without entering the incipient spin stage. I learnt this during PPL and again during Aero training.

If anything, that video shows rudder can be quite effective at "picking up a wing"!

[Tee Emm]

FWIW, I recall being taught to hold the control column level and recover with rudders at one of three linked schools at Moorabbin in the early 90s.....

Just goes to show that the "pick the wings up with rudder" is a cancer taught at some flying schools as gospel. Where this duff gen originated from heaven knows but one thing is for sure, and that it's has been regurgitated for the past 40 years and passed down from instructor to instructor.

[Centaurus]

Where this duff gen originated from heaven knows but one thing is for sure, and that it's has been regurgitated for the past 40 years and passed down from instructor to instructor.

Tee Emm is offline Report Post

It may go back to the time the Wirraway was the RAAF advanced single engine trainer. The stall in a Wirraway was characterised by a sharp wing drop. Instinctive use of aileron to prevent further wing drop invariably caused the wing to drop further because of the increased angle attack of the aileron on the dropped wing. While that was true of some wartime designs, post war trainers like the Cessna and Piper range were subject to civil certification and wing design meant stalls were benign

Wartime accent was placed on not using aileron initially and this was reflected in flying training manuals of that era. Rather than use aileron. use of rudder was taught based on the premise that skidding the aircraft to wings level was better than risking further wing drop if aileron was used.

As we now know, this technique was not optimum for wing drop recovery but it's interpretation persisted through the years possibly because the majority of flying instructors employed by aero clubs were former military personnel. Thus the myth was perpetuated to this day despite the correct method of recovery from a dropped wing at point of stall published in the CASA flight instructors manual.

[BEACH KING]

Very interesting topic.
I had used the same instructor to conduct my BFR (or whatever CASA calls them now) for probably 5 previous reviews. During a demonstrated stall the first time I flew with the bloke, he rebuked me sharply for not using the rudder to pick up the dropped wing.
I was startled and confused at the time, as I had been taught in my training by a very experienced instructor (and good mate) to "push forward and feed it to her"!
I thought I must have forgotten the correct procedure, as I discussed it with him at length on the ground after that first BFR flight, where he explained that you can't use aileron to pick up the wing as it's already stalled. I already knew that, but didn't think that getting wings level was a first priority.
For my most recent BFR, I lost track of expiry date and needed a review in a hurry. I was most fortunate by chance to run across a very well known and experienced warbird pilot and instructor who offered to do the review immediately!
During the stall demonstration I picked up the dropped wing with rudder whilst pushing forward and applying power. After the stall recovery, he remarked that he didn't know that I enjoyed aerobatics. I informed him that I certainly had no love of aerobatics. "Keep that rudder at stall **** up and you will have to learn to love doing them" was his comment. On the ground he told me that using the rudder in this way was very unwise.
So there you go.

[Arm out the window]

By the early 80s, and I think before that (as well as since), the taught RAAF method has certainly been (paraphrased slightly):

1. Simultaneously apply full power, control column centrally forward to unstall the wings and rudder to prevent further yaw;
2. When control regained, level the wings with aileron and recover from the dive.
3. Post-recovery actions (i.e. check configuration, confirm no overspeed / overstress, orientation, why did the stall occur?)

So the rudder pickup method must have gone out of favour before that time. I didn't fly it, but accidents have shown that the Winjeel could certainly drop a wing harshly at the stall particularly with flap down. The CT4 on the other hand was pretty benign.

[PDR1]

Originally Posted by BEACH KING

I thought I must have forgotten the correct procedure, as I discussed it with him at length on the ground after that first BFR flight, where he explained that you can't use aileron to pick up the wing as it's already stalled.

Well maybe you can't, or maybe you can - it depends on the type. Firstly the aileron on the other side will still be working, and that will reduce the roll rate. Secondly whilst a significant chunk of the dropping wing may be stalled, it's quite possible that the region by the aileron won't be stalled due to washout, changes of wing-section, slats/slots or any of a number of other design features explicitly intended to assure aileron control at the point of departure.

So even the aileron on the dropping wing may well be able to impart some useful roll-moment and reduce the amount of wing-drop while the driver is attending to the most important task of unstalling the wings to recover normal control. It's also worth noting that if the aeroplane has an dihederal then applying out-spin rudder actually INCREASES the AoA on the "stalled" wing, so quite how it's supposed to unstall it remains a mystery.

I'm an arrogant SoB by nature, which is why becoming an airline pilot probably wouldn't have been the ideal career choice for me. But when I was doing my basic PPL training my first instructor taught this "pick up the dropping wing with rudder" cockermamie and I refused. My earliest flying was air-experience flying on Chipmunks (AEF 6 at Abingdon - happy days!) and one of the instructors there had been very firm with his standard patter:

"Never thrash with the rudder close to the stall unless you're either deliberately trying to spin, or you're flying over a graveyard and don't have the money for a proper funeral" (he would then explain it at length, if you asked, but the patter phrase stuck in the memory as intended). So when my "proper" instructor tried to teach this I was shocked. In the lesson debrief we had a stand-up row about it, with the essential outcome that I found a different instructor!

€0.07 supplied,

PDR

[jonkster]

So even the aileron on the dropping wing may well be able to impart some useful roll-moment and reduce the amount of wing-drop

If the dropping wing is stalled and you are adding aileron to pick it up you are asking (depending on type) for something it may not give, in fact depending on type you may get exactly the reverse of what you want - the stall on that wing gets deeper and the wing drops more and the yaw increases.

In fact doing that is a great way to make a number of aeroplanes drop into a spin quite nicely. The stalled wing is being sent into a higher AoA and so stalls deeper and yaws and rolls more (one potential one, under the right conditions is the DHC-1 Chipmunk you have experience with BTW)

Some aeroplanes are more pilot proof than others and are designed to allow a pilot to mush their way with ailerons in a stall without biting. Some don't.

I think it is important to encourage a reaction of pilots in stalls not to use aileron (unless they do so deliberately and consciously and with a knowledge of the consequences for the aircraft they are flying).

I would pick up a pilot who tried using aileron in a stall to stop the roll.

[Deltasierra010]

In some probably older aircraft you can pick up a wing with the rudder to an extent, but why not lower the nose and get out of the stall, it's much safer. In an aerobatic aircraft using full opposite rudder with neutral ailerons will stop rotation in a spin, otherwise using coordinated stick and rudder together is a very good habit to get into.
In 30 years of flying, only once did I really scare myself, a low slow uncoordinated final turn, just made it right in front of the CFI, his comment " you won't do that again will you", "now get back in again and we do it properly together", 3 times.

[Sunfish]

Be aware that at least one of the modern designs (Evector Sportstar) has very bland stalling behaviour, it sort of mushes down in a power off stall with some aileron authority, very safe indeed.

This lead one young instructor to enough overconfidence in this "mild" behaviour to really stuff it up. The result was a spin to the left followed by one to the right as he tried to recover it.

Be very careful of guys who say "This aircraft can't bite you! Watch this!". Don't ever poke the lion with the stick - superior airmanship and all that.

[FullOppositeRudder]

With my PPRuNe name, I hesitate to enter this discussion, however here is the extract from the Gliding Federation of Australia Instructor's Handbook:

FULL SPIN RECOVERY
The standard recovery action from a fully developed spin is:
•
Full opposite rudder
•
Ensuring ailerons central, move stick forward until spinning stops
•
Centralise rudder
•
Recover from dive
This recovery method is universally known and accepted. It forms the basis on which gliders are certified in this critical area of flight. There is no justification for varying it.

I've never spun a powered aircraft, but I know that this works for every glider I've sat in where I've had to try it out .....

Respectfully submitted,

FOR

[Tankengine]

Originally Posted by FullOppositeRudder

With my PPRuNe name, I hesitate to enter this discussion, however here is the extract from the Gliding Federation of Australia Instructor's Handbook:

I've never spun a powered aircraft, but I know that this works for every glider I've sat in where I've had to try it out .....

Respectfully submitted,

FOR

Yep, but that is for a full spin, and it will work with nearly all powered aircraft.
What the discussion is about is more just a dropped wing at the stall, which is best recovered by forward stick first.
Putting in full rudder when NOT spinning is likely to cause one!

[Virtually There]

Forward stick isn't going to help you when you're inverted . . . But I digress.

How many here fly aircraft that don't yaw towards a dropped wing when it stalls?

I think it equally dangerous to advocate NOT using rudder to keep an aircraft in balance as it is to suggest using FULL rudder on a dropped wing that may inadvertently end in a snap roll in the opposite direction.

[rich34glider]

I agree with Virtually There - use enough opposite rudder to prevent further yaw/roll (not necessarily full deflection) and enough central forward stick to reduce AoA and get both wings flying again - there is no need to exclude one control input or the other, although it is possible to prevent wing drop in a turn by relaxing the back pressure alone if you're quick. And certainly don't use aileron to try and correct a roll caused by a stalled wing .. period! You will probably get away with it in many GA aircraft but in others you won't. If you apply the same poor technique (picking up wing drop with aileron) you learnt in a forgiving aircraft, while flying a less forgiving aircraft, it will spin. Shocking that these aerodynamic fundamentals known for 100 years are still so widely misunderstood.

[Centaurus]

Some power on, rapid stick back and simultaneous full rudder. Flick roll. Sad. Awful.

I don't know about "sad - awful" but the manoeuvre described above was often demonstrated by our instructors on the Wirraway during the pilot training course. It was demonstrated because, among other high "G" manoeuvres, a harsh pull-out from a loop or dive bombing could result in a flick roll. I vaguely recall the Wirraway had a 7 G limitation. You could use the flick roll manoeuvre at the top of a loop to make it a roll off the top. Good fun for 20 year old trainee pilots training for a war.

[jonkster]

The video I made those comments about showed a flick entry into a spin for the unsuspecting pilots, made at an altitude too low to recover. That what was what was sad and awful to me.

[PDR1]

Originally Posted by jonkster

If the dropping wing is stalled and you are adding aileron to pick it up you are asking (depending on type) for something it may not give, in fact depending on type you may get exactly the reverse of what you want - the stall on that wing gets deeper and the wing drops more and the yaw increases.

Except that, as covered in the paragraph before the one you have extracted, in reality it's not a whole wing that stalls - a stall develops somewhere on the wing and in many cases the region with the aileron will stall last (because aeroplane designers have put a bit of thought into the design).

And while we're here - another similar depressingly common myth/misunderstanding is the idea that deflecting an aileron downwards increases the angle of attack of that part of a wing and risks stalling it of the wing is close to it's stalling AoA. This is not true. A lowered aileron is just a flap, and no one says "if you're close to the stall for <deity's> sake down't lower the flaps because you'll stall the wings!"

The lowered aileron is a flap, and just adds camber to the wing which will probably* increase the stalling AoA of that part of the wing and delay the stall.

There is a convention that *defines* the AoA strictly in terms of a line drawn through the centre of the LE radius and the tip of the TE, but that's just a geometric convention for ease of drawing. It isn't an aerodynamic datum.

PDR

* Government Health Warning: Airfoils vary. Your aeroplane could be at risk if you make assumptions about the behaviour of an airfoil. Consult your airfoil's lift polar before relying on rules of thumb about its behaviour...

[Arm out the window]

The lowered aileron is a flap, and just adds camber to the wing which will probably* increase the stalling AoA of that part of the wing and delay the stall.

If the stall has progressed to a wing drop I would suggest that even if you reckon your aileron isn't as stalled as the rest of the wing (which is a big if), then the rapidly increasing upward flow because of the drop will be pushing it past that point pretty quickly. A flap is not just a flap when it's hurtling downwards at a great rate, surely.