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

[Centaurus]

Unbelievable that at least one well known flying school in the Melbourne area allows its instructors to teach students to skid with full rudder in order to level the wings after a wing drop at point of stall. The theory being by using full rudder to pick up a dropped wing at point of stall, the dropped wing goes faster than the other wing, gains more lift and thus levels both wings rather than use aileron to level the wings.

Are CFI's so inundated with regulatory paperwork that they have no time to regularly supervise their instructors by not only listening to instructors giving pre-flight briefings to students to ascertain their standard of briefings, but also fly regularly with new students as a quality control measure.

Seems to this observer that CFI's prefer to stick with doing IFR and licence tests instead of checking the blind teaching the blind which is often the case of new instructors teaching new students.

This wing drop rubbish needs to be debunked before someone goes into a spin caused by very low airspeed and full rudder. CFI's of flying schools need to test their instructors knowledge of correct stall recovery technique before allowing them to get loose on student pilots. In turn, CASA need to do their job and audit what is taught on flying instructor courses then spot check graduates on stall recovery techniques.

[megan]

Is the rudder thing from the days of yore when aircraft had different design standards? No washout for example to ensure stalls first at the root. Was one explanation I've seen, but don't know it's veracity.

[waren9]

you need to read and understand your own link pilotchute :rolleyes:

[pilotchute]

I took it down instead. How could I possibly have had a differing view

[27/09]

NZCAA teach using the rudder and not ailerons for recovery. Who to believe?

Actually they don't say that at all.

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

The correct method of stopping autorotation is to break the yaw-roll-yaw cycle, and since aileron cannot be used effectively to stop the roll, rudder is used to prevent further yaw. The nose is lowered simultaneously (backpressure relaxed) with the application of rudder, and this will stop the roll immediately

My bolding.

Once the the aircraft is unstalled the ailerons are used to roll the wings level.

[john_tullamarine]

Oh dear ...

While acknowledging that some of the ancient Types flying do have aileron vices, anything of recent design should be far better behaved.

For interest, the current design standard requirements to be found at -

(a) FAR 23.201 (http://www.ecfr.gov/cgi-bin/text-idx?SID=1d9fa92f17f6cbdc28a7181182f2f864&mc=true&node=se14.1.23_1201&rgn=div8)

(b) FAR 23.203 (http://www.ecfr.gov/cgi-bin/text-idx?SID=1d9fa92f17f6cbdc28a7181182f2f864&mc=true&node=se14.1.23_1203&rgn=div8)

(c) FAR 23.207 (http://www.ecfr.gov/cgi-bin/text-idx?SID=1d9fa92f17f6cbdc28a7181182f2f864&mc=true&node=se14.1.23_1207&rgn=div8)

and, I daresay, the EASA words will be somewhat similar ...

Comments, such as in this thread, regarding the dangers of using aileron (with a caveat for the few old ragbag - but delightful - machines still around), in essence, are nonsense.

What the design and certification fraternity would prefer to see is

(a) avoid the stall

(b) if you can't manage (a), then stall

(c) subject to AFM/POH guidance, initial action is to unstall by unloading the wings ie reduce backstick inputs

(d) then, when the thing is definitely unstalled, roll and pitch back to normal flight while adjusting thrust settings.

Unfortunately, the operational folks still have overwhelming hangups about minimum height loss. Progressively, post AF 447 changes to industry practices, this will change.

Centaurus' thoughts are on track .. and that from a chap who was brought up right in the middle of the old practices. Rudder should never be used to pick up anything .. only to prevent further yaw which, in itself, can lead to undesirable excitement.

[jas24zzk]

One of my favourite subjects.

For me it comes down to type familiarity.

Some types will allow you to pick up a dropped wing with aileron, others that response will simply deepen the stall.
I think its a case of the instructor knowing his type and training accordingly. The other side of that is further type specific training.

Anyone that has trained on Grummans, AA1-AA5 will tell you, that you pick the wing up with rudder, as ailerons deepen the stall and accelerate the rotation.

It also comes down to space available. The training is done high...where you have space to unload and lower the nose....you don;t have that luxury in the flare.

A PA-28 will forgive you picking the wing up with aileron, many other types won't.

[megan]

Previous thread.

Wing dropping stall recovery. [Archive] - PPRuNe Forums (http://www.pprune.org/archive/index.php/t-451470.html)

Pieces from the net.

Wing drop recovery

When a wing does drop, its downward movement increases the AOA even more, thus bringing it deeper into the stall. Using ailerons at that moment would not be of any help at all as picking up the wing (downward aileron) also increases AOA but then at the wingtip. The stall is now developed from wingroot to the tip.and The stall/spin accident is aviation’s #2 killer of general aviation pilots. This is in part because during training the modern airplane has to be forced to spin and it requires considerable judgment and technique to get the spin started when loaded with the student and his instructor. However, when a passenger or baggage is added to the back, this same airplane may be put into an accidental spin with surprising ease.

Spin avoidance is a matter of practicing cross-control stalls until a conditioned reflex of using the rudder is ingrained. During a power-on stall where the wing falls to the left or right, the pilot who has not developed the conditioned reflex of using the rudder will instinctively apply aileron to stop the roll. Modern airplanes, those built since the late 1940’s, are required to have aileron control during a stall. This control is not sufficient to stop the roll without the addition of rudder. In fact, when the airplane rolls to the left and right aileron is used to counter it, the left aileron is deflected downward to increase lift on the left wing. Lift and drag are directly proportional, so the increased drag resulting from the increased lift may actually aggravate the problem.

If, instead of aileron, the rudder is used to “pick up” the wing, the airplane will not spin. To set up the autorotation required to develop a spin the nose of the airplane must turn or yaw at least 90 degrees. Rudder will stop the turn and prevent the spin.

I have trained more than 2,000 primary students and each one performed a spin prior to their first solo.

And somebody we may know? ;)

Using The Rudder - Aviation Safety Article (http://www.aviationsafetymagazine.com/issues/34_15/unicom/Using-The-Rudder_10885-1.html)

Compare what Mr. Laming says aka "At the low speed normally associated with a stall, the so-called “pick-up-the-wing-with-rudder” technique he advocates has the potential to cause a spin in the other direction" to the bolded piece above.

[Arm out the window]

Anyone that has trained on Grummans, AA1-AA5 will tell you, that you pick the wing up with rudder, as ailerons deepen the stall and accelerate the rotation.


Would you really use it to pick the wing up, i.e. level your wings, or just as I think most people are saying, to prevent it dropping further while you're using forward stick to unstall the wings, then level them with aileron as you continue the recovery?

It surprises me that using rudder to level the wings, or even bring them partway back in the other direction to the drop, would be a technique nominated by the manufacturer or taught on the type, but as always I will be happy to be corrected if that's the case.

[megan]

From

https://www.airpilots.org/file/666/teaching-stalling.pdf

In the past it has been considered acceptable to use rudder to pick-up any wing drop whilst teaching the signs of the full stall. This technique is dangerous and has been cited as one of the causes of more than one stall/spin fatal accident. Use of the rudder should be restricted to preventing any further yaw, should any develop. If significant yaw/wing drop occurs whilst trying to teach the full stall signs, recovery action should be taken immediately. If all of the full stall signs were not taught before recovery proved necessary, then it will be necessary to give an additional demonstration.So it seems it may have been considered de rigueur at some stage.

[Captain Sherm]

Rudder, in general, for yaw

Have a look at https://en.m.wikipedia.org/wiki/American_Airlines_Flight_587

[Tankengine]

If you ignore the wing drop for a moment and JUST PUSH FORWARD most types will recover nicely. ;)

[gerry111]

I reckon that having been an aeromodeller from a rather young age, has helped me understand how aircraft actually fly. For example: W&B of early free flight models. Then later on to fast radio controlled models where any low level bad mistake ended up with a pile of expensive wreckage. Plus gliding, where one actually got to stall and spin in the resident gliding club Kookaburra or Blanik..

These experiences taught me a lot of respect when flying GA. :)

[Tee Emm]

If you ignore the wing drop for a moment and JUST PUSH FORWARD most types will recover nicely


Very true. Perhaps you should have included promptly levelling the wings with aileron immediately the stall is broken.

[Tankengine]

Very true. Perhaps you should have included promptly levelling the wings with aileron immediately the stall is broken.

Yep, but that is secondary - the pushing forward unstalls the wings, after that you do what you need to do! ;)

[jonkster]

my 2c FWIW

use and amount of rudder depends on the aircraft.

eg from the flight manual of one aircraft I have instructed in:

"Alieron control response in a fully developed stalled condition is marginal. Large aileron deflection will aggravate a near stalled condition and their use is not recommended to maintain lateral control. The rudder is very effective and should be used for maintaining lateral control in a stalled condition with the ailerons in a neutral position"


That said, *full* deflection rudder in a stall recovery to stop yawing in a stall (as the OP is suggesting is being taught) sounds a little odd but is that actually what is being taught? And on what aircraft? Or is the instructor teaching the student to centralise ailerons and avoid controlling yaw with aileron by appropriate use of rudder?

2. Many students are scared of stalling. Which is sad IMO. When they end up as instructors that fear is contagious and the cycle continues. This is not a criticism of instructors but is something that good instructors should (and often do) work at correcting. Properly taught, deliberately stalling (and recovering) an aeroplane should not be something that instils fear in students for the remainder of their flying career. Sometimes it seems initial stall training consists of clumsy and rushed entry with the instructor's voice and demeanor on edge and with a pronouced nose high attitude and then a sudden drop that for a student who so far has only ever experienced smooth coordinated flight can be alarming.

Initial stall exposure should be gentle and give the student reassurance that they can handle the aircraft in all its normal operating envelope - it should allow the student plenty of time to experience how the aircraft feels at near stall speeds so their response and feel can become instinctive and they recognise the stall signs well before they happen and can recover appropriately and instinctively when they do enter the stall. (Which also is great for developing feel on landing).

Stall training should be fun not frightening.

IMHO.

[Clare Prop]

Need to teach the human factors that lead to making decisions that lead to stall/spin accidents (including the instinct to level the wings when actually it is a lower priority than reducing angle of attack) rather than draw pretty pictures in a briefing then go up to 3000 feet and start yanking around on the controls and putting the aircraft into unrealistic attitudes.

If an instructor is teaching a fully developed spin recovery (ie full opposite rudder) in an incipient spin scenario then they are probably just copying what thy were taught and haven't gone below the thin veneer of rote learning that is all that is required to become a flying instructor.

[Arm out the window]

That's scary if any instructor is actually dumb enough to think that fully developed spin recovery actions are appropriate for a stall recovery - not sure any flying school would be allowing that level of incompetence, surely? Let's hope not.

[roundsounds]

This situation needs investigation by CASA. If in fact the reports are correct, the CFI, Flight Examiner(s) who issued the FIRs, the instructors and their students need to undergo remedial training.
This technique is not only dangerous, it is not an accepted practice and contradicts the Flight Instructors Handbook guidance and the Part 61 MOS.
There is no need to pick up a wing during a stall, rudder is used to prevent yaw in the event of a wing drop and ailerons used to level the wings after recovery from the stall.

[jack11111]

When receiving my primary training, before doing stalls, we always warmed up with MCA flight.

This seemed to make stalls no big deal and I think this was great instruction technique.

[LeadSled]

Folks,
Rounsounds suggests this should be investigated by CASA.

I agree, that CASA should investigate itself, as the poor sod who is the butt of this thread is only "demonstrating" the competency required to be demonstrated by CASA.

See CASA (in)competency standards for pilots. 'tis all in black (or maybe blue) and white.


In the CASA "one size fits all" world, full opposite rudder is the prescribed corrective action for a wing drop at or near the point of stall.

That this "one size fits all" is almost never appropriate (depending on the aircraft) is too subtle for CASA. That "full opposite rudder" at the point of a stall is the recommended method of spin entry for a number of aircraft is probably "lost" on CASA experts. Or that some aircraft at the stalling angle of attack have the rudder almost completely blanketed, but the ailerons remain effective, due the design.

The real answer is "Know your stuff, and which aeroplane you happen to be flying today".

Just one further pertinent question: Why would anybody think that CASA has the competence to look into this matter of CASA incompetence, and come to a competent answer??

Tootle pip!!

[Clare Prop]

MOS unit A5.2 - Recover from incipient spin:

a) perform pre-manoeuvre checks
b) recognise an incipient spin
c) use the aeroplane's attitude and power controls to execute an incipient spin manoeuvre from the following flight conditions and, using correct recovery technique, regain straight and level flight with height loss commensurate with that available attitude (simulated ground base may be set)
(i) straight and level flight
(ii) climbing
(ii) turning

Nothing there about applying full opposite rudder.

[jonkster]

Nothing there about applying full opposite rudder.

nor is it in section A5.1 in stall recovery competencies - that has just the following

control the aeroplane by applying the required pitch, roll and yaw inputs as
appropriate for various stall recovery scenarios

Where does CASA say always use full rudder? :confused:

[Lead Balloon]

What, then, does CASA say is the "correct recovery technique"?

[Frank Arouet]

From immediate memory both Piper Colt and Maule, (and many others), have interconnected rudder and ailerons. Application of either will correspond with a reaction not fully anticipated in the alleged CAsA advice. I could go on with evidence of an interconnection being tampered with on a Maule but it's all written up in "The Phelan Papers". I think the advice is sound for the Sopwith Camel though and even then the engine needs to have the fuel turned off. 'Blipping" tends to exaggerate the situation.

[djpil]

CASA says stuff in the Flight Instructor Manual.

[jonkster]

djpil is correct - in the new replacement document for the old "pub 45" manual for guidance of instructors it describes instructors stress the importance of using rudder not aileron to prevent yaw in stall recovery.

I can't find where CASA ever says to use full rudder in stall recovery anywhere though (happy to be proved wrong).

The OP's report doesn't reveal how they came across this 'full rudder' technique being taught. Was it from a first hand experience with an instructor (eg when doing an instructors rating renewal) or was it reported to the OP by a student? Is it possible there has been some miscommunication about what was being shown and that is not what is being taught? And on what aircraft?

[Arm out the window]

RECOVERY WITHOUT POWER
Control column forward to un-stall the wings. As the speed increases ease out of the dive. Emphasize that if a wing drops, rudder is used to prevent yaw into the direction of the lowered wing. The wing is raised with aileron when it is un-stalled.

RECOVERY WITH POWER
Brief the student that the recovery using power is similar to that when no power is used with the addition that full power is applied at the commencement of recovery. Point out that you will be demonstrating that use of power results in recovery being made with a much decreased height loss compared with the recovery without use of power. It is important to stress that power, if used too late, i.e. when the nose of the aeroplane has dropped below the horizon, will result in an increased loss of height. Stress that the recovery using power is the normal method of recovering from a stalled condition of flight.

Straight from the CASA Flight Instructor Manual.

[john_tullamarine]

full power is applied at the commencement of recovery

Caveat - be sure that this is applicable to/suitable for your aircraft.

The certification approach is to have a delay between the initiation of recovery and increasing power. Some of the problems which may arise, especially with higher power aircraft, include normal prop force (which might give you a nasty surprise with a nose pitch up) and (probably only a problem with big engines) a quasi-Vmc response due to the old P-factor problem.

Re the current certification approach to stall recovery, you might like to have a read of AC23-8C (https://www.faa.gov/documentlibrary/media/advisory_circular/ac%2023-8c.pdf) at p 92 where the good words read -

Recovery..... The power used to regain level flight may not be applied until flying control is regained. This is considered to mean not before a speed of 1.2 VS1 is attained in the recovery dive.

Straight from the CASA Flight Instructor Manual

All fine and beaut, I guess .. just one more example of the operational folks not reading what the certification folks might have done before giving the aircraft a tick in the box.

[cattletruck]

Regardless of all the theory in the world on stall recovery there is nothing a bit of time in an aerobatic rated aircraft won't fix in a few minutes.

I was fortune to indulge in exploring deep stalls in a Bellanca Decathlon as part of my training - 5 fully stalled complete spins was the then legal limit which gave one plenty of time to appreciate the stable state of a stalled aircraft and room to think.

The topic of this thread reminds me of a story I read in Charles Kingsford Smith's unofficial autobiography. He was pax in a RPT twin in South America when noticing the engines were full bore and the plane was not climbing. He made his way to the cockpit only to see a mountain range dead ahead that the pilots were going to drive straight into. He told the pilots to drop the nose to pick up speed to achieve a better rate of climb. As CKS would say "always fly the wing" - something Bob Hoover was great at demonstrating.

[Arm out the window]

Fair enough John, but I would have thought that the delay in introducing power would be specified to simulate the difference between a test pilot who was expecting the stall to occur and a 'real' pilot perhaps, a bit like where they have a certain time between rolling off power and lowering the collective in rotary wing autorotation tests?

The reason I say that is that I've never seen a stall recovery procedure from a flight manual that says to delay the introduction of power - not saying it's never done, just never seen it in the types I've flown.

[john_tullamarine]

Some of the experienced TPs about the place have strongly antipathetic views about slamming on thrust at the point of stall recovery, for what it may be worth to the typical pilots out there.

My concern is that folks should be aware of the typical certification animal so that they can consider the potential for pitfalls doing the usual minimum height loss style of recovery.

Similar concerns for when one should initiate recovery. The stall procedure has varied somewhat over the years and, sometimes, not knowing what the certification was can present some excitement. For instance, a tale related at a FT course I did years ago .. by a very experienced instructor TP .. concerned a USAF student TP in a well-known civil light twin .. thought it would be interesting to progress into the stall to see what happened.

Aircraft flicked into an inverted spin.

The instructor knew what was about to happen, the student learnt a lesson about doing his history homework rather than making it up on the fly. For that particular aircraft, the rules of the day had the recovery commencing promptly.

Not knowing what the OEM really did can have surprising consequences. Generally, the pilot only has the AFM/POH guidance and, if he is interested, a review of the TCDS and relevant issue design standards documents.

[compressor stall]

As a digression - Immmediate power application is something Airbus pilots (and others no doubt)are 'unlearning' in the sim.

Airbus say (amongst other things) nose over to break the stall then, when no symptoms exist, then gently increase power.

Also at high altitude a good whack of nose down >10deg has less height loss than a 5 degree or so nose down. Your ROD might be double, but your speed recovery out of the symptoms happens in under half the time.

And back on topic, and Airbus also says level the wings simultaneously with decreasing the AoA.

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.....

[djpil]

Straight from the CASA Flight Instructor Manual.it is worth reading both chapters 9 and 13. I wonder if the various authors/editors bothered to read what others had written or retained from the old one?


..... in a Bellanca Decathlon ...... - 5 fully stalled complete spins was the then legal limit ......no such limit that I'm aware of however the current FAR 23 puts a limit of 6 turns on new types/models certified.

[Clare Prop]

I show this video to students as part of the pre flight briefing for the slow flight and stalling exercise. There are lots of contributing human factors which the student needs to identify, but look what happens at the end when he applies full rudder.

https://www.youtube.com/watch?v=7nm_hoHhbFo

[Clare Prop]

There are mistakes in the CASA Jandakot Visual Pilot Guide too. When I asked CASA about this, eg the taxi call for VFR including "request clearance" which had controllers snarling I was told with a shrug "It's not a controlled document". The reference is the AIP, not the CASA guide.

Similarly, the reference for instructors is the MOS, not the Flight Instructor Manual. I have encountered newly trained instructors and students coming up for test who have never seen or heard of the MOS.

[LeadSled]

Clare Prop,
The relevant section was a wing drop in a stall, not incipient spins.
If the offending "full opposite rudder" is no longer in the MOS as described, at least some notice has been taken of "industry input", which is a good thing --- I certainly had an "animated" discussion on the subject at "the highest levels of CASA" --- at an SCC meeting, including Skidmore.
I must look it up and check, when I have the time, and nothing else is pressing.
I am bound to comment that too many of you are into a "one size fits all" mindset, even if different sizes, based on various posts, consider carefully the wise words of John T., and know which aeroplane you are flying.
They ain't all the same!!
Tootle pip!!

[jonkster]

I show this video to students as part of the pre flight briefing for the slow flight and stalling exercise.

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

Not quite the scenario being discussed here but one I think has happened many times in GA and students need to have thought about (and even better simulated dual at altitude) is with a rough running engine, ie partial power, trying to stretch a glide to make a field and needing to turn the aircraft to line up with the field and also having a wariness to bank the aeroplane low to the ground so the pilot unconsciously starts booting in rudder to skid the aeroplane around onto final.

I sometimes used to set up that scenario (at altitude and with a briefing beforehand of course) with some students and on BFRs.

My old man had a rhyme he was taught ab initio in the RAAF on Tiger Moths

Watch him spin, watch him burn, held off bank in a gliding turn :(

[Clare Prop]

This is the section about recovery from a stall.

A5.1 – Enter and recover from stall

(a) perform pre-manoeuvre checks for stalling;

(b) recognise stall signs and symptoms;

(c) control the aeroplane by applying the required pitch, roll and yaw inputs as appropriate in a smooth, coordinated manner, trims aeroplane accurately to enter and recover from the following manoeuvres:

(i) incipient stall;

(ii) except for multi-engine aeroplanes, stall with full power applied;

(iii) stall without power applied;

(iv) stall under the following conditions:

(A) straight and level flight;

(B) except for multi-engine aeroplanes, climbing;

(C) except for multi-engine aeroplanes, descending;

(D) approach to land configuration;

(E) except for multi-engine aeroplanes, turning;

(d) perform stall recovery as follows:

(i) positively reduce angle of attach;

(ii) use power available and excess height to increase the aircraft energy state;

(iii) minimise height loss for simulated low altitude condition;

(iv) re-establish desired flight path and aircraft control;

(e) recover from stall in simulated partial and complete engine failure configurations.


Let me know what your definition is of "incipient spin" The only amendments to the MOS since it became a legislative instrument in 2014 have been for ATPL and IR test . There has never been anything in the MOS about "full opposite rudder" it is one of the many Old Wives Tales that we come across.

Absolutely agree the one size fits all thing is not appropriate and is lazy/ignorant instructing. I see it a lot particularly relating to the use of carb heat and electric fuel pump in PA28s. Don't get me started on CSU power settings... "My instructor told me" does not override the POH.

[john_tullamarine]

A couple of points there which might be pushing the certification tick in the box.

Possibly be a good idea to have the studes read through the relevant bits of FAR 23 and AC 23-8 (versions appropriate to the particular training Type - ref TCDS) to get some background prior to frightening themselves.

There isn't, necessarily, a danger in doing something different to the certification .. just a potential concern that something surprising might turn up along the way and then the pilot is on his/her Mat Malone. If the bit which is surprising has some underlying problems for recovery, that just might be beyond the non-FT knowledgeable trainee pilot ?

[Lead Balloon]

positively reduce angle of attachI 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 (https://youtu.be/orFDFybzfEQ?t=10m53s)

[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]

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:
(http://www.aviation.3wg.aafc.org.au/wp-content/uploads/Instructors-HB-Part-2.pdf)
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]

With my PPRuNe name, I hesitate to enter this discussion, however here is the extract from the Gliding Federation of Australia Instructor's Handbook:
(http://www.aviation.3wg.aafc.org.au/wp-content/uploads/Instructors-HB-Part-2.pdf)
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]

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.

[Runaway Gun]

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


Actually forward stick does help, regardless if you are straight and level, Inverted, or already in a dive. It's all about reducing AOA.

[roundsounds]

Actually forward stick does help, regardless if you are straight and level, Inverted, or already in a dive. It's all about reducing AOA.

Unless you're pulling negative G. ie sustained inverted flight, pushing over the top of a stall turn etc.

[Runaway Gun]

Unless you're pulling negative G. ie sustained inverted flight, pushing over the top of a stall turn etc.

True. I don't know many pilots brave enough to push hard enough to do that. Or stupid enough - for I quite enjoy that kind of thing ;)

[cattletruck]

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...

That's the spirit!

Nowadays on some modern types if it all gets too hard you can just push a button (or pull a lever) that will release a big parachute to sort it all out for you.

[djpil]

..... in many cases the region with the aileron will stall last (because aeroplane designers have put a bit of thought into the design).Yep however there are flight states which cause the initial stalled region of the wing to be further outboard.

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..
Consult your airfoil's lift polar before relying on rules of thumb about its behaviour...Yep, I certainly recommend checking out lift coefficient vs angle of attack plots with different control surface or flap deflections to see that the stall AoA is reduced with downwards control/flap deflection.

[PDR1]

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.

Fair point.

But then once the wing-drop has gotten into it's stride the only thing that will do any good is unstalling the wing anyway - using ailerons won't be any worse than using rudder. If fact using the ailerons will recamber the wing such that it will "unstall" in the vicinity of the ailons a lttle soon, where as if the aeroplane has any dihederal the yaw from any anti-rudder input will increase the angle of attack of the dropped wing and delay the "unstalling" (due to the geometry of yaw and dihederal).

PDR

[PDR1]

Yep, I certainly recommend checking out lift coefficient vs angle of attack plots with different control surface or flap deflections to see that the stall AoA is reduced with downwards control/flap deflection.

Rather than draw lots of diagrams, may I refer the honourable member to a previous post by Cuban 8 (another member of this parish) here (http://www.pprune.org/tech-log/126007-reduced-angle-attack-when-flaps-lowered.html#post1288155) which puts the point in far fewer weords than I ever would:


As a former Aerodynamicist, I think it is important to re-iterate the points that Taylor G and Bookworm have made.

The Cl/AoA debate is an issue of definition. By convention in aerodynamics, the chord line of an aerofoil is defined for it's clean configuration with nothing "hanging out". As we begin to deploy trailing edge high lift devices, we are indeed modifying the characteristics of the aerofoil - the most significant change being the introduction of a greater camber. Commensurate with this, the aerofoil's true chord is also modified - but by convention, the reference chord remains that for the clean aerofoil. Thus, on a characteristic Cl/AoA plot, it appears that the aerofoil stalls at a lower AoA, but with a greater Clmax. In reality, the AoA at which the aerofoil stalls is usually greater than for a clean aerofoil. A secondary effect of this is very beneficial to use as pilots - the pitch angle at which we a achieve a given AoA is reduced.

The same principle is true for Fowler slotted flaps and similar devices. The effect of such devices on a Cl/AoA plot often look too good to be true compared to other trailing edge devices, in that they offer a relatively large increase in Clmax. However, you have to consider that Fowler slotted flaps are also significantly increasing the aerofoil wetted area, but this fact is not reflected in the calculations - the aerofoil reference area remains that for the clean aerofoil. The increased area is hence absorbed into the increased Clmax the devices offer, slightly misleading!

Of course, day to day, the theory offered by BEagle is all we really need to know. However, when your really trying to understand what is going on, such simplifications can be misleading.

Rgds

Cuban_8


PDR

[Virtually There]

Just to be clear, the actual stalling AoA does not "increase" or "decrease" - the stalling angle of the chord line in relation to the relative airflow remains the same. You are simply changing the camber/chord line by dropping the trailing edge.

But then once the wing-drop has gotten into it's stride the only thing that will do any good is unstalling the wing anyway - using ailerons won't be any worse than using rudder. If fact using the ailerons will recamber the wing such that it will "unstall" in the vicinity of the ailons a lttle soon, where as if the aeroplane has any dihederal the yaw from any anti-rudder input will increase the angle of attack of the dropped wing and delay the "unstalling" (due to the geometry of yaw and dihederal).

This is the bit I'm trying to understand: are you referring to positive aileron? That is, left wing drops, apply left aileron to reduce camber of left wing (and AoA) in the hope it will unstall sooner?

As for dihedral effect, my understanding is when a wing stalls and drops, the aircraft yaws into the dropped wing as a result of induced drag. This causes a brief side-slip in the opposite direction (skid). The higher wing will now be moving into the sideslip - which increases its AoA and causes the lift vector to move further aft, compounding the yaw and causing the aircraft to roll further to the left.

The only way to break the yaw-roll cycle in the incipient stage is to apply opposite rudder to not only bring the aircraft back into balance, but change the relative airflow of the dropped wing to reduce its AoA. This happens when the dropped wing moves forward (and has nothing to do with "increasing the speed of the wing to increase lift", as the wing is already stalled!).

If I am missing something - and I'm not trying to be smart - then I'm very open to re-education.

As an aside, I know from experience it is entirely possible to ride a stall - stick all the way back - wings level for hundreds of feet of lost altitude simply by dancing on the rudder to keep the aircraft in balance. It works. I've done it. No aileron. All rudder.

[KayPam]

Hello
I have not read all 4 pages of the topic but just the first post.

Applying large amounts of rudder in order to keep wings level is correct procedure when stalling. It is large amount of ailerons that should be banned.

Where do I have this knowledge from ?
I was on several flights with one of the best pilots there is : chief test pilot for an aircraft manufacturer and former chief test pilot instructor.
A/C was SET.
When approaching stall, he wanted to see on which side the particular aircraft would bank. Afterwards, on the ground, some small adjustments were made. But during the test, he would make large inputs, up to full rudder, in order to keep level for as long as possible.


HOWEVER there really is no point other than test flight in doing this !
If a student or inexperienced pilot (in this case meaning someone without extensive aerobatics experience) tries to do it and mixes up the foot side, or puts too much foot, he will end up in a spin.
Whereas he could just have pushed on the stick with a few degrees of bank : who cares ? He will level the wings with the ailerons once the stall is recovered.

[jonkster]

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!"


With respect PDR, I disagree. I think in a basic aircraft without slats etc, if you lower flap whilst actively maintaining the same pitch attitude of the aircraft (ie the same angle to the airflow), you *will* increase the AoA of the wing and will be closer to the stall.

So if you were very close to stall and then extended flaps without changing the pitch I think I may very well be saying "for <rude word>ing <deity's> sake you need to lower the nose captain if you are extending flap now! ;)

In simple S&L un-accelerated stalling of an aircraft in landing configuration you have a lower nose attitude compared to the clean stalling attitude, if you were to raise the nose of a dirty configuration to a similar position for clean stall, the wings would be even more stalled.


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.


Again I respectfully disagree.

Have a look at Aerodynamics for Naval Aviators (in my 1965 revision, page 39 and 40)
http://www.ballyshannon.com/air/aoaliftgraph.jpg

Notice how the max lift point actually reduces significantly for flap extension.
FWIW, a C172 has something like Fowler style flaps

I agree that in a sense yes ailerons are just asymmetric flaps. The difference however is in their use. Typically extending flaps involves lowering the pitch attitude to produce the same lift. Similarly it allows slower flight before reaching the critical angle (ie a lower stall speed) by increasing lift and drag. What it doesn't do is allow the aircraft to stall at a similar or higher AoA (or for simple stalls at a higher or similar pitch attitude).

The ailerons are not being used in the same way as flaps. The aircraft attitude is not being changed to account for the aileron's change to the effective shape of the aerofoil. If you have an outer wing near the point of stall and without changing its relative motion to the airflow, deflect the aileron down, you are pushing it closer to the stall.

[Virtually There]

I would have agree with the jonkster. And it's pretty easy to demonstrate a departure of control by using opposite aileron at the point of stall.

Have a look at this video and see what the pilot does with the yoke right at the point of stall:

WKIk-dqml6U

Let's not forget the primary function of a basic flap - as opposed to an aileron - is to increase the surface area of the wing to increase lift for the same speed - the penalty being drag. The change in chord line merely facilitates a lower nose attitude for a better view during approach.

As far as I'm aware, ailerons (not flaperons) do not change the lift coefficient of the wing in the same manner flaps do. In addition, there seems to be a bit of confusion about the reference point of AoA in relation to flaps. Flaps change the chord line, so if you do not alter the point of reference of AoA for a clean wing, then of course the AoA of the wing as a whole will decrease. But the stalling AoA of the chord line in reference to the relative airflow is still the same.

As for the application of flaps at the point of stall, this has been addressed by at least one person who claims to have tried it in a Chippy: http://www.pprune.org/questions/202707-flaps-stalling.html

[rich34glider]

Something to be considered - I was fortunate enough to start my flying career in gliders and so was exposed to proper spin training from the start. Funnily enough, the military also taught full spin recoveries ... but I also went all the way through the GA world to CPL without doing a single one. If you'd like to experience the reality of what all of this theoretical talk is about, go for a couple of flights with your local gliding club: Unusual Attitude and Spin Training for non- Glider pilots (UAS) (http://www.glidingaustralia.org/club-resources/201-unusual-attitude-and-spin-training-for-non-glider-pilots-uas)

[djpil]

As far as I'm aware, ailerons (not flaperons) do not change the lift coefficient of the wing in the same manner flaps do. In addition, there seems to be a bit of confusion about the reference point of AoA in relation to flaps. Flaps change the chord line, so if you do not alter the point of reference of AoA for a clean wing, then of course the AoA of the wing as a whole will decrease. But the stalling AoA of the chord line in reference to the relative airflow is still the same.nope

A simple aileron is just like a simple flap as far as the aerodynamics of the aerofoil is concerned.

Airflow separation results from adverse pressure gradient. Deflecting that flap or aileron increases the negative Cp near the leading edge therefore that adverse pressure gradient will increase so ....

Someone kindly provided the usual charts from wind tunnel data where we retain the chord line of the aerofoil with nil flap or control surface deflection. That is my usual reference.

Some calculations we do are via the so-called thin aerofoil theory where we change the chord line to follow the deflected trailing edge. A fine theory but generally doesn't lead us to a calculation of stalling angle of attack, at least not a realistic one.

[Virtually There]

Airflow separation results from adverse pressure gradient. Deflecting that flap or aileron increases the negative Cp near the leading edge therefore that adverse pressure gradient will increase so ....
... it will separate (stall) sooner.

I get that. And I get that more camber = more lift = more drag. And that reducing XTE (trailing edge position) increases Cl.

But then once the wing-drop has gotten into it's stride the only thing that will do any good is unstalling the wing anyway - using ailerons won't be any worse than using rudder. If fact using the ailerons will recamber the wing such that it will "unstall" in the vicinity of the ailons a lttle soon, where as if the aeroplane has any dihederal the yaw from any anti-rudder input will increase the angle of attack of the dropped wing and delay the "unstalling" (due to the geometry of yaw and dihederal).What I am trying to come to terms with is how recambering the wing and increasing the chord line AoA (through use of aileron) helps unstall a dropped wing? Is not that the whole point of washout?

And in reality - as demonstrated in the video I posted - opposite aileron at the point of stall can actually facilitate a wing drop.

I know I am only referring to basic GA type aircraft, but for the purposes of this conversation, that's what most of us fly. Also, most of us have done a few stalls and spins in our time and at least in my experience, wing drop at the point of stall can be countered through use of opposite rudder, whilst opposite aileron has the reverse (and undesired) effect.

My point is, I can't see how "ailerons won't be any worse than using rudder" when experience has taught me that's not the case. That's just my experience in what few types I've stalled and spun, including those with dihedral (Piper's etc). Even an aero trainer like the Decathlon has a small amount of dihedral.

I know you guys do this for a living, so what is it I'm missing?

[jonkster]

Just me but I would avoid saying "pick up the wing" with rudder. I would prefer to say in a stall, control yaw with rudder and keep ailerons neutral.

Use ailerons to return to wings level once the stall is broken.

Pretty sure "out spin" aileron at stall (ie aileron that you would think would stop the wing dropping) will actually help make a nice positive spin entry in Chipmunks if I recall correctly. (Someone with more recent time on them please correct me if this wrong!)

It has been a long time but in a Citabria, I recall talking students through stalling in a climbing left turn with a bit of power with a little too much rudder and holding off bank with aileron. (This simulating at altitude what might happen in real life trying to make a unplanned landing site due weather or maybe rough running engine, turning onto final and needing to stretch the glide and the pilot unconciously is avoiding banking too steeply because they are low to the ground so they skid the final turn around on rudder).

I recall it makes for a quite sharp spin entry and a loss of several hundred feet in a blink. The Citabria normally has a very good manners and a gentle predictable spin entry from a simple unaccelerated stall.

Teaching people it is OK to use ailerons to keep wings level in a stall is something I would feel very wrong about doing. On some aircraft it works fine but it is not a good habit to have people get into.

[djpil]

Is not that the whole point of washout?Yes indeed however there are situations where, despite washout and inboard stall strips etc etc, the initial point of stall is outboard on one wing which can result in an aggressive wing drop/spin entry - all explained here Traffic Pattern Stalls (http://apstraining.com/traffic-pattern-stalls/)


And in reality - as demonstrated in the video I posted - opposite aileron at the point of stall can actually facilitate a wing drop.

I know I am only referring to basic GA type aircraft, but for the purposes of this conversation, that's what most of us fly. Also, most of us have done a few stalls and spins in our time and at least in my experience, wing drop at the point of stall can be countered through use of opposite rudder, whilst opposite aileron has the reverse (and undesired) effect.Agreed, effect of aileron depends on the type of aeroplane however. Take a look at http://www.flightlab.net/Flightlab.net/Download_Course_Notes_files/10_Spins.pdf with fig 8 showing aileron effects (imagine an aerofoil with a more abrupt stall) however read the text about effect on the roll damping etc.

As you say, most of the aeroplanes we fly were certified to older or very old standards so I like to stick to that script.

(Fairly new certification requirements of FAR 23 etc do require the aileron to be effective the normal sense throughout the stall - saw some video yesterday of flight tests of a new type showing exactly that.)

I know you guys do this for a living, so what is it I'm missing?If you are missing something then a chat over a glass of red (with jonkster and john tullamarine maybe) is easier than words here (at Avalon yesterday I saw a CASA alcohol test guy on his mission - lucky he didn't see me at any of the boozups).

[Virtually There]

Thanks for the links. The "Falling Leaf" manoeuvre is what I was referring to earlier about using rudder at the stall to prevent a wing drop.

Unfortunately, I'm nowhere near Avalon :(

I recall it makes for a quite sharp spin entry and a loss of several hundred feet in a blink.
Just described the Mallard incident, I believe.

[Ultralights]

A very good video on upset recovery, stalling, and most importantly, Stalling while Skidding, and slipping.

Not once is anything mentioned anywhere about picking up a wing drop, let alone using aileron or rudder to pick it up. Slipping at the point of stall is nothing to worry about, Skidding on the other hand will kill you at low level. and both are demonstrated here.
https://youtu.be/ovXZxwUN-ZI
skip to about 20 mins for the skidding slipping stuff.

"Keep your ball centred or your balls are gonna be all over the ground" - Josh

[Virtually There]

They may not say it, but they certainly do it: 00:35 for example.

And those slipping turns at 22.00+ where the aircraft remains stable in the stall (no spin entry) - that's all opposite rudder.

Just sayin'.

[jonkster]

yes exactly! The bit you point out is with the aircraft cross controlled but not yawing, it is slipping (due excess rudder) but basically tracking in a straight line. You can do that in a Citabria (in the video a Decathalon) and it won't bite. Similar to how you would side slip to lose height on final.

If however you are cross controlled and yawing due excess rudder (ie skidding) and it will bite. Similar to trying to skid it around on a base/final turn and avoiding too much bank. Stall then in the Citabria (and Decathalon in the video) it enters a spin really smartly.

Why I suggest saying use rudder to control yaw NOT to "pick up a dropped wing".

[Virtually There]

Yep, side-slipping is the technique we use to add drag to lose height and/or slow down the Decathlon on final as it doesn't have flaps.

[A37575]

Yep, side-slipping is the technique we use to add drag to lose height and/or slow down the Decathlon on final as it doesn't have flaps.

If I recall correctly, the pilot of the 'Gimli Glider" (the Air Canada Boeing 767 that ran out of fuel and forced landed flapless on a 7000 ft disused airstrip) side slipped the 767 to lose height on final. Now that would have been something to see.

Slight thread drift coming up. Interestingly, so called "dead stick landings" from high altitude is not something that is formally practiced in jet transport flight simulators. Yet, most type rating syllabus require practice at volcanic ash encounter resulting in loss of all engines. By working through the appropriate check list, it is envisaged that at least one engine is finally started and allows the crew to save the day.

Everyone loves a happy ending of course but one could argue there is a chance that none of the engines will start and you are left with a dead stick landing into the sea or a conveniently placed long runway.

However, that is considered so statistically improbable by regulators that practice dead stick landings (if done at all) are seen as nothing more than a bit of fun at the end of the session rather than a serious exercise of handling skill and good airmanship. In other words cross your fingers and pray it will never happen for real.

One of the points the captain of the Air Canada Boeing 767 made during the investigation, was that he wished his company had allowed him to practice at least one dead stick landing in the simulator rather than him having to nail it first time for real at Gimli. He had a good point, I thought. CASA please note:ok:

[LeadSled]

Now that would have been something to see.Folks,
The B767 side-slips very nicely, indeed it even does it on auto-pilot coupled approaches with a cross-wind, as did the L1011.
The B747-400 was mix and match, on a coupled approach it was part side-slip and part offset heading for drift, as too much "wing down" could result in a serious seniority scraper. Hand flying, it side-slipped very nicely.
There are no AFM side-slip limitations for either of the above.
Tootle pip!!

[kaz3g]

I read with interest an article on Avweb today...

" Some older airplanes have performance peculiarities that can kill you if you walk into a corner of the envelope ignorant of their existence. For example, on any number of older airplanes, attempting to use the ailerons to pick up a low wing at close to stall speed may result in aileron reversal. That is, applying left aileron will cause the airplane to roll right. Sometimes vigorously. The reason is the simple lack of aerodynamic knowledge at the time the airplane was built and the descending aileron stalls that section of the wing. Not being aware of that fact can result in an attention-grabbing event for the pilot new to old airplanes. Rule of thumb if you stall an older airplane and a wing drops—pick it up with the rudder, keep the ailerons neutral."

No wash out on an AUSTER.

Kaz

[Tankengine]

I read with interest an article on Avweb today...

" Some older airplanes have performance peculiarities that can kill you if you walk into a corner of the envelope ignorant of their existence. For example, on any number of older airplanes, attempting to use the ailerons to pick up a low wing at close to stall speed may result in aileron reversal. That is, applying left aileron will cause the airplane to roll right. Sometimes vigorously. The reason is the simple lack of aerodynamic knowledge at the time the airplane was built and the descending aileron stalls that section of the wing. Not being aware of that fact can result in an attention-grabbing event for the pilot new to old airplanes. Rule of thumb if you stall an older airplane and a wing drops—pick it up with the rudder, keep the ailerons neutral."

No wash out on an AUSTER.

Kaz


Arrrrggghhhh!
Don't "pick it up with rudder"!!
Apply rudder to stop further wing drop while lowering the nose to come out of the stall and once recovered use appropriate controls to recover to level flight. Recovering from the stall is number one priority.

I do have Auster experience. ;)

[Flying Bear]

I have heard two instructors in the past 24 hrs try to sell me that rubbish during development training.

The accompanying patter actually amounted to a recipe for disaster...

The instructor schools responsible for their initial training should hang their heads in shame...

Simply put, rudder controls yaw. Prevent yaw during stall entry (assuming non-turning stall) and recovery using rudder (best achieved by having Bloggs focus on a reference point throughout entry and recovery and work his/her feet to keep the nose "locked on" in the yawning sense). Who cares about the wing "drop" if there's no yaw? Any wing drop can be corrected with aileron once the wings are unstalled (ie elevator control forward of stalled stick position).

Easy, and guaranteed to avoid a spin (which is part of the point of this).

Spin avoidance for dummies (like me!) - prevent stall and/or prevent yaw. Done!

Stalled stock position - not taught in schools these days and not understood by the vast majority of pilots... but don't get me started on that!

Happy stalling!

[simmple]

We were recovering from upsets in the sim recently, instructor says I don't have to do any but young first officer does as " you have done hundreds in your early training and as an instructor in years gone bye, these chaps only do one or two on their basic training"
WTF are these guys trained as, follow the magenta line, say the right words and nothing can go wrong!

[Centaurus]

We were recovering from upsets in the sim recently, instructor says I don't have to do any but young first officer does as " you have done hundreds in your early training and as an instructor in years gone bye
Nice to see your instructor had such touching faith in you. Did he tick your box without having certified your competency on upsets? Naughty naughty,:E

[mates rates]

Nice to see your instructor had such touching faith in you. Did he tick your box without having certified your competency on upsets? Naughty naughty,:E
It's a box ticking exercise these days.Did he fluke a stall recovery? If so,tick a box-Competent. It's called competency based training,and its the greatest load of crock I have ever seen!!!

[kaz3g]

Arrrrggghhhh!
Don't "pick it up with rudder"!!
Apply rudder to stop further wing drop while lowering the nose to come out of the stall and once recovered use appropriate controls to recover to level flight. Recovering from the stall is number one priority.

I do have Auster experience. ;)

I posted the article because it again raises the fact that older aircraft may not have the same aerodynamics as later ones do. I think Centaurus made a comment to that effect in an earlier post.

Not that I'm in the habit of aggressively stalling it, except when landing, these days in deference to both our ages, my technique is to rapidly lower the nose while applying rudder to stop it yawing. As it's now unstalled, I level the wings and add power as appropriate bearing in mind the yellow arc starts at 95 KN. Seems to work.

I have more than 500 hours in the AUSTER and now feel I'm in control more often than not. :rolleyes:

I also have about the same time in gliders and I've never got over that instant stick forward reaction to low inertia.

Kaz

[Tankengine]

I posted the article because it again raises the fact that older aircraft may not have the same aerodynamics as later ones do. I think Centaurus made a comment to that effect in an earlier post.

Not that I'm in the habit of aggressively stalling it, except when landing, these days in deference to both our ages, my technique is to rapidly lower the nose while applying rudder to stop it yawing. As it's now unstalled, I level the wings and add power as appropriate bearing in mind the yellow arc starts at 95 KN. Seems to work.

I have more than 500 hours in the AUSTER and now feel I'm in control more often than not. :rolleyes:

I also have about the same time in gliders and I've never got over that instant stick forward reaction to low inertia.

Kaz
"Picking it up" with rudder is even more likely to help you enter a spin in an older aircraft!
Glider training is generally much better in this regard than power. :)

[TBM-Legend]

I've seen a Thai Inter DC-8 side slip to lose height doing a straight in approach on finals landing Rwy 18 at Butterworth, Malaysia. Very impressive. Swedish Captain..

[gerry111]

I was a passenger in a Thai International DC-8 from Bayan Lepas (Penang) to Kai Tak (Hong Kong) during 1982.

TBM-Legend, So why did the DC-8 you mention land at Butterworth? That's pretty unusual I would have thought? :confused:

[downdata]

Wouldn't trying to pick up the wing with aileron send it into a full spin like in the video here?

https://www.youtube.com/watch?v=1_FoXr4e3mM

[IFEZ]

Hahaha back to base for a change of underwear and to make a booking with an instructor for a lesson in power-on stall recovery :D.


(Love the feigned bravado for the camera - woohooh yeaahh..!)

[404 Titan]

downdata

If you don't unload the wing this is the end result. Standard recovery requires unloading the wing first and foremost ie relax the back pressure, stop any rotation with rudder and level the wings with aileron. With the exception of a few wing platforms, this is the only correct technique. Use of power will vary too based on aircraft type etc. As for the myth of using rudder to pick up a wing, you do this at your own peril. It's been an incorrect technique taught by inexperienced instructors, and a lazy regularly littered by people that have been taught incorrectly as well.

[downdata]

downdata

If you don't unload the wing this is the end result. Standard recovery requires unloading the wing first and foremost ie relax the back pressure, stop any rotation with rudder and level the wings with aileron. With the exception of a few wing platforms, this is the only correct technique. Use of power will vary too based on aircraft type etc. As for the myth of using rudder to pick up a wing, you do this at your own peril. It's been an incorrect technique taught by inexperienced instructors, and a lazy regularly littered by people that have been taught incorrectly as well.

What about this video ... full right aileron didn't exactly pick up the wing ...

https://youtu.be/WKIk-dqml6U

[404 Titan]

downdata

If you look closely he reloads the wing back up as he rolls in aileron. As I said unload the wing "AND KEEP IT UNLOADED", stop the yaw with rudder, level the wings with aileron. Simultaneously power is coming in and as airspeed increases to a safe level gently raise the nose being careful not to cause a secondary stall by loading up the wing too much again. Whether I'm doing this in a C172 or an A330, the principal is the same. If you unload the wings they are now unstalled and the wing is flying. At this point ailerons are effective and won't cause a wing drop as long as you keep the wing unloaded. If you reload it up again you get what you see in the video. Text book wrong technique.

[cirrus driver]

In cross country soaring flight pilots thermal very close to the stall in order to circle as tightly as possible. We experience frequent wing drops as thermal strength varies. The instinctive and immediate reaction is a quick movement of the stick forward and immediate recovery. Glider pilots have no power lever!
Stalling and incipient spins, then developed spins are thoroughly taught to the gliding student and required in every Annual flight review. We also use our feet all the time on the rudders not merely using them as foot rests but never use full rudder in an incipient spin but only in a fully developed spin then it is standard recovery - full opposite rudder - stick central-move stick slowly forward until rotation stops- neutral rudders -recover gently from the dive. There is no power lever only the power of gravity!
I am a gliding instructor and power pilot , tug pilot plus Mecir qualified but gliding taught me about stalls and spins not power instructors except on my initial aerobatics endorsement in a chipmunk

[Tee Emm]

I've seen a Thai Inter DC-8 side slip to lose height doing a straight in approach on finals landing Rwy 18 at Butterworth, Malaysia. Very impressive. Swedish Captain.. Sounds like an unusual and rather unstable approach by an overconfident captain:eek: He'd be gone a million if that manoeuvre was recorded on the QAR if fitted in those days?

[gerry111]

So why was the Thai DC-8 landing at the military Airbase Butterworth, rather than Penang's civilian Bayan Lepas? :confused:

[LeadSled]

So why was the Thai DC-8 landing at the military Airbase Butterworth, rather than Penang's civilian Bayan Lepas? http://cdn.pprune.org/images/smilies/confused.gifGerry 111,
Probably because of the same reasons we landed Malaysian and Qantas B707 at Butterworth, that's where the scheduled services went in those days.

Tee Emm,
As to the side-slipping and "gone a million", why?? Do you know it was prohibited on the DC-8 by AFM?? Also, on at least some DC-8, reverse could be used in-flight on (I think) the inboard engines to increase ROD.

Both were prohibited on B707, but subsequent Boeing with pylon mounted engines had no side-slip limitation, and both the B767 and B747-400 side-slip across the wind in a coupled approach. I would expect the B-777/787 does the same.

So why not a pilot flying manually, what has "over confidence" got to do with it??

Tootle pip!!

[Tee Emm]

both the B767 and B747-400 side-slip across the wind in a coupled approach. I would expect the B-777/787 does the same.


My ignorance - I didn't know that. Thanks for the info. I recall being cautioned by my instructor on Tiger Moths, where side slips to flare height was the norm because of no flaps, that significant IAS errors can be expected while side-slipping.
I can understand that especially as the side wind vector into an open cockpit could blow one's goggles off. :eek: Are there airspeed errors to be allowed for in jet transport side slips? If side slips are permitted in big jets, where does the compatibility to stable approach criteria come in?

[boofhead]

Can't believe some of the comments in this thread. if you fly a Spamcan and were taught by a CFI who has also only flown a Spamcan, or if you fly an Airbus, I can see the reason for your lack of knowledge about aerodynamics particularly as it applies to slow flight, stalls and spins but surely the majority must have some idea?

For example, why does a wing drop at the point of stall? That's right; the airplane is yawing. Which means one wing has less lift and will drop. How would you expect to stop this? That's right, stop it from yawing by using the control fitted to most airplanes for this purpose; the rudder.

In many airplanes, even Spamcans (especially if they are misrigged) application of aileron to stop or pick up a dropping wing, unless coordinated rudder is also used, will cause a further wing drop and expose you to an incipient spin, which all modern pilots are taught to fear.

As a flight instructor I fight all the time with pilots who fly with their feet on the floor or consider that those pedals thingies are foot rests. All the way from Cubs to jets.

Just as spinning was banned as too frightening, slow flight has gone the way of the Dodo, and stalls are maneuvers to be feared, soon rudders will become useless appendages. For many, they will not be missed. A pity things have deteriorated to this extent and I fear the standards will continue to drop until we are all replaced by drones. Or has this already happened and I did not notice?

[boofhead]

My ignorance - I didn't know that. Thanks for the info. I recall being cautioned by my instructor on Tiger Moths, where side slips to flare height was the norm because of no flaps, that significant IAS errors can be expected while side-slipping.
I can understand that especially as the side wind vector into an open cockpit could blow one's goggles off. :eek: Are there airspeed errors to be allowed for in jet transport side slips? If side slips are permitted in big jets, where does the compatibility to stable approach criteria come in?

You will get significant IAS errors while side slipping in any airplane that only has one static port, including C712 and C152. The IAS will go up or down depending on which way you are slipping.

[markkal]

Go out there fly a certified aerobatic aircraft ( For your safety) with a competent instructor, try different scenarios, incipient stall, aggravated stall (Falling leaf) fully developped spin and recoveries, takes 1 flight to demonstrate, many more to master, but worth a 1.000.000.000 words. And an argument that will never be resolved by endless talking will be sorted out once and for all.

Still cannot understand how people can advocate incipient spin recovery with ailerons, it is contrary to all the laws and aerodynamics and physics...And that full rudder recovery presents the risk of spin in the opposite direction.

Unconscious applied full forward stick (Held there) can lead to negative spin, and what nobody even mentions in this thread is that when application of "Full rudder" is applied i needs to be followed by centralising the rudder to complete the recovery maneuver. It is the lack of exposure to these scenarios, the unconscious inputs or the freezing at the controls due to fear of the unknown, which leads to this misunderstandings and consequent endless debates.

Do yourself a favour, go out there and experiment the whole thing then come back with your comments, ...I bet the debate will not wander in all directions as it is now. There are test pilots out there who have devised procedures for all scenarios meant for the average pilot. It's their job, so follow the flight manual, trust me they know what they are doing.

[Centaurus]

.And that full rudder recovery presents the risk of spin in the opposite direction.


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..

[markkal]

Centaurus, you have a point, however whatever one is thaught or shown ( Unless brainstormed and actually practiced long enough to become instinctive ) as far as risks asociated with counter wing drop with ailerons or with full rudder, I can tell you from experience (My own at the beginning and from countless pilots students and instructors) the initial reaction to an incipient stall is 1000% aileron to raise the wing. And this happens during training when one expects the maneuver, think about when it comes as a surprise..


Likewise, unless one is trained to use full rudder I have NEVER seen anyone applying full opposite rudder, only a tad of opposite foot (despite believing otherwise), but always full opposite aileron as an instinctive reaction..

Anyway whatever the debate, I can assure you the the majority of accidents are due to not to recoveries techniques , but rather from the fear and lack of confidence arising from the risk of losing control.

It is well known that in these scenarios, the mental process is impaired with either uncosncious random inputs or just no inputs at all . This has nothing to do with skills or the lack of them, It is a normal process that can only be reversed with training. We humans have to learn and practice in order to be able to perform..


Trust me, it has done marvels to boost my confidence and skills, it can benefit anyone, go take a full course on spins ( Please in stages :-) with a qualified instrcuctor and appropriate aircraft. Slow flight, incipient or developped spin, all will come smoothly under control

Spatial awareness, coordination, light touch at the controls, dissipation of fear and it's consequences are guaranteed. Then the whole behavior at the back of the envelelope (Slow flight/second regime) will improve accordingly, the correct reflexes will be ingrained. After that you'll be the judge to what works and what does not, able to experience and correct when need be..

[Icarus2001]

Unconscious applied full forward stick (Held there) can lead to negative spin] Okay so what is "negative spin"?
You either spin the right way up, more or less, or inverted.

[rich34glider]

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.

[cattletruck]

Y'know, those training hacks are bl@@dy hard to viciously stall. With power off they take forever to reach stall buffet and by then the horn has been blaring a while and the stick is right under your chin. With power fully on the wing drops are slightly more interesting but even with the horn blaring the b@stard thing still manages a positive climb rate.

Go out there fly a certified aerobatic aircraft ( For your safety) with a competent instructor, try different scenarios, incipient stall, aggravated stall (Falling leaf) fully developped spin and recoveries, takes 1 flight to demonstrate, many more to master, but worth a 1.000.000.000 words.

Fully agree, it should be part of the training syllabus. Exploring the stall in a more slippery certified craft does wonders to one's overall handling skills in this area, to the point that it becomes a non-issue.

[josephfeatherweight]

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.

Yeah, but the discussion isn't about spin recovery - it's about stalling.

[jonkster]

another 2c from me.

The spin follows the stall and is a stalled manouvre. If we teach students to use ailerons in the stall to "pick up the wing" (because most modern aircraft retain effective aileron in the stall) but not to do that in a spin, I think that is expecting a bit much - I have seen more than once (many times in fact) pilots who are introduced to a stall off a climbing turn (often who have never had it introduced in their ab initio training) who frantically try and correct by using full deflection aileron as the aircraft starts to autorotate and also who seeing the aircraft rapidly pitch down, pull back hard. In a panic situation this is not a great response. Reinforcing aileron use in the stall is something I feel is not doing students a good service.

I have no problem teaching people to neutralise ailerons and if necessary use appropriate rudder in the stall (NB *not* to "pick up the wing" but to stop any associated yaw - allow the wing to be low - don't let the nose start wandering though ). If they become adept at this (falling leaf great for this) they will hopefully be more likely to use the same technique if the aircraft ever autorotates or enters a full developed spin.

That way we use a common technique in all stalled manouvres rather than one for the stall and one if it is developing into (or is) a spin.

[Clare Prop]

Application of rudder is to prevent yaw, most aeroplanes will only yaw if you forcefully boot the rudder, yank on the ailerons or apply power. Most aircraft will recover without any input from the pilot at all.

Unless the aircraft is in a fully developed spin use of rudder will probably just make things a lot worse. Ref the Avweb video with the Cirrus going into a snap roll at about 200 feet AGL because someone did exactly this, it is a vid I show students before the stalling lesson.

https://www.youtube.com/watch?v=7nm_hoHhbFo&t=25s

Plus a proper analysis rather than old wives tales here https://www.richstowell.com/documents/Transport_Canada_TP13748E.pdf

"One feature that stands out in all except one of the 39 stall/spin accidents examined is that knowing how to recover from the stall or spin was of no benefit to the pilots in these circumstances. They stalled at altitudes so low that once the stall developed, a serious accident was in progress"

This is what students need to study, not have instructors yank and shove little aeroplanes around at 3500 feet.

[Runaway Gun]

Skill in recovery from stalls is needed, especially stalls in those situations that lead to a wing drop and autorotation requiring immediate, precise, and confident handling. Once the spin develops, as this study shows, the situation is too often an accident in progress.

[machtuk]

I find it amazing that the stall recovery debate comes up constantly over the years with varying techniques for recovery. Even some academics cant decide on how lift is actually produced so how the hell do we expect anyone to know stall recovery? After nearly 40 years driving planes from low powered SE's to heavy jets & thousands of hours I've not once stalled a plane accidently or put myself in a position where it's likely, only a few times during early training & even then it was a quick basic let it all go & fly away, at Alt of course. The above video says it all, very steep AoB, loading up the wing by pulling back on the stick whilst maneuvering close to the ground, all of which should never have been done in the first place, that's just poor handling & little knowledge of what NOT to do! Today's modern planes with good overall training don't need to be flying near the stall at all. Correct handling doesn't mean you should know how to get out of a stall it means don't put yourself in that position in the first place! Turning onto final at low Alt is not the time to test your abilities to recover from a stall no matter how you reckon its done, most wont survive, avoidance is your best insurance!

[JPJP]

This is shown on a big screen at the beginning of a major airlines unusual attitude and stall training. If it doesn’t increase your pulse, you’re probably dead. Two MD test pilots completing a test card. No survival gear, as it wasn’t supposed to involve anything sporty. Watch the PF hands and the CRM. The first thing he does is unload the wing - pushes forward.

https://vimeo.com/8511733

[megan]

Not a straight stall, but all crossed up with sideslip, 90° of right wheel, wonder how much rudder fed in?

[jonkster]

I find it amazing that the stall recovery debate comes up constantly over the years with varying techniques for recovery. Even some academics cant decide on how lift is actually produced so how the hell do we expect anyone to know stall recovery? After nearly 40 years driving planes from low powered SE's to heavy jets & thousands of hours I've not once stalled a plane accidently or put myself in a position where it's likely, only a few times during early training & even then it was a quick basic let it all go & fly away, at Alt of course. The above video says it all, very steep AoB, loading up the wing by pulling back on the stick whilst maneuvering close to the ground, all of which should never have been done in the first place, that's just poor handling & little knowledge of what NOT to do! Today's modern planes with good overall training don't need to be flying near the stall at all. Correct handling doesn't mean you should know how to get out of a stall it means don't put yourself in that position in the first place! Turning onto final at low Alt is not the time to test your abilities to recover from a stall no matter how you reckon its done, most wont survive, avoidance is your best insurance!

People continue to stall and to spin. Particularly following engine failures or partial failures low to the ground, or when operating low to the ground skud running, particularly in strong winds. Many times you hear eye witness reports of accidents where they describe the aircraft dropping nose low and/or turning steeply and hitting the ground.

I believe teaching people stalling is not so much that they can recover if they accidentally stall but so they are familiar with the situations it can happen in and will recognise when they are putting in inputs that are leading to a stall/spin and will avoid continuing with those inputs.

I also think it should be taught so they are comfortable with the aircraft and don't fear it. Every now and then I come across pilots who fly unnecessary high speed approaches with corresponding long floats, clumsy landings and wasted runway and and when I query them they say they are scared of stalling so keep the speed up. Recently I had a pilot who pretty much dived the aircraft onto final, increasing speed for the base-final turn, fearful that he might stall in a turn low to the ground.

I think we should be teaching people good hand skills and proper flying techniques, rather than dumbing things down and teaching people to drive the aeroplane, to never have the opportunity to learn and experience from outside 'normal' situations and to be fearful of what might happen if things move outside their comfortable cocoon of 'normal' flight.

Stalling and low speed flight is part of that. I really believe that taught properly stalling should not be a scary or uncomfortable process - it should not be a big deal and should result in the pilot feeling more in control, more confident and understanding more about the aircraft and should give them an intuitive feel for when they are pushing the limits and what will happen if they continue. I think that stalling is often taught poorly because the instructor was taught poorly and so is not comfortable with stalling (I think that is far more common than instructors who want to show off to the student).

[rich34glider]

Application of rudder is to prevent yaw, most aeroplanes will only yaw if you forcefully boot the rudder, yank on the ailerons or apply power. Most aircraft will recover without any input from the pilot at all.

Unless the aircraft is in a fully developed spin use of rudder will probably just make things a lot worse. Ref the Avweb video with the Cirrus going into a snap roll at about 200 feet AGL because someone did exactly this, it is a vid I show students before the stalling lesson.

https://www.youtube.com/watch?v=7nm_hoHhbFo&t=25s

Plus a proper analysis rather than old wives tales here https://www.richstowell.com/documents/Transport_Canada_TP13748E.pdf

"One feature that stands out in all except one of the 39 stall/spin accidents examined is that knowing how to recover from the stall or spin was of no benefit to the pilots in these circumstances. They stalled at altitudes so low that once the stall developed, a serious accident was in progress"

This is what students need to study, not have instructors yank and shove little aeroplanes around at 3500 feet.
If you continue teaching people to ignore appropriate rudder use in the incipient spin scenario then they will nearly always revert to picking up a dropped wing with aileron (law of primacy) which will actually work in many modern aircraft, but will produce the below result in others - note aileron & rudder deflections. Is it a good idea to teach for the best-case scenario or the worst? https://www.atsb.gov.au/media/5772435/fig2_prelim.jpg

[Centaurus]

I think that stalling is often taught poorly because the instructor was taught poorly and so is not comfortable with stalling (I think that is far more common than instructors who want to show off to the student).
Never a truer word.

[Arctaurus]

Agree

Generational "dumb down" training inevitably results in a reduction in skill levels across all disciplines (Pilots, Instructors, Trainers, etc etc)

The argument that because we don't permit, and therefore don't need to train for a spin event will be of little comfort to anyone who inadvertently finds themselves in such a scenario without the tools and training to recover.

[Propjet88]

There are aspects of this discussion that disturb me, including dangerously incorrect statements by some posters, so a few bullet points to ponder:

A wing stalls when the critical angle of attack (stalling angle) has been exceeded on that wing. In the training situation, the classical focus is on the situation where both wings stall at the same time. A wing drop at the stall is invariably caused by one wing stalling before the other. This “uncommanded roll” may have been caused by:

Yaw being present as the stall was approached. This could be perhaps be due to change of engine torque. In a training situation, students (and instructors) often fail to correctly balance with rudder when reducing power to enter a clean stall or when applying power during recovery. I also see lots of pilots controlling direction on finals by over-use of rudder, rather than using it correctly to balance the aircraft.
Differential condition of the wing(s) e.g. ripples in the surface; dents in the leading edge; rigging differences in the wing or the flaps / slats; on a laminar flow wing (such as a glider) even bug squash on a leading edge that results in airflow breaking away (stall) at a lower angle of attack that on the other wing.


Teaching recovery from a stall with a wing drop has classically involved what came to be known as the “standard stall recovery”:

· Ailerons neutral

· Reduce the angle of attack with elevator (stick forward)

· Simultaneously apply full power (if available)

· Sufficient rudder “to prevent further yaw”

Over the years, in some quarters, this last point has been translated into “pick up the dropped wing with rudder”. To “pick up the wing” requires yaw in the other direction and as the aircraft is still close to the stall, it may well result in the opposite wing stalling. The technique is used in certain aerobatic manoeuvres such as the “falling leaf” where the aircraft angle of attack is held just off the stall and the pilot applies rudder one way and then the other to stall one wing then the other. As a basic stall recovery technique, it is potentially dangerous.

Significantly, the military moved away from using rudder “to prevent further yaw” years ago as it was “negative training” for future aircraft types. Extensive trials were conducted on light piston training aircraft as well as on turboprop and pure jet trainers to look at height loss during stall recovery. Interestingly it was discovered that use of rudder to prevent further yaw had absolutely no effect on height loss – and even could distract the pilot from simply using elevator to un-stall the wing or wings and then using aileron to level the wings when the aircraft was no longer stalled.

A number of modern aircraft – some of which are used for training (e.g. Cirrus) have design features that allow ailerons to be used at the stall (such as marked washout or chord twist that causes the inboard section of the wing to stall well ahead of the outboard section containing the ailerons). However, the licencing system allows a pilot to fly any type of light aircraft and I'd suggest that the concept of “primacy” will prevail in a startle / surprise situation that would almost certainly be present in an inadvertent stall. This would result in a pilot reverting to whatever had been drummed into them during training. If this involved use of aileron, it is likely to lead to very bad outcomes in an aircraft that does not have the design feature.

Bottom line is that elevator is the primary control to un-stall the wing(s). Use of aileron or rudder can be problematic near the stall – more so in some types than others. Teaching use of rudder to “pick up a wing” at or close to the stall is dangerous.

Fly Safe
PJ88

[Horatio Leafblower]

Bottom line is that elevator is the primary control to un-stall the wing(s). Use of aileron or rudder can be problematic near the stall – more so in some types than others. Teaching use of rudder to “pick up a wing” at or close to the stall is dangerous.

Thank you!

If AoA is the problem.... AoA is the solution.

[Rashid Bacon]

Good advice:

Ailerons neutral and unstall the wing (reduce the AoA by pushing the stick forward). Stalling is ONLY an angle of attack phenomena and can occur at any airspeed or attitude.
Add power as required - maximum may be needed
Then apply sufficient rudder only to stop further turning (AFTER the wing is unstalled)

Applying rudder too early (when at least one wing is stalled) creates a yaw moment that can make the situation far worse.

Unfortunately, I suspect the outcome of the Swan river event may not have been different even if this technique was followed, due to the low entry altitude.

[djpil]

When I’m exercising the privileges of my USA CPL I do what the enlightened FAA says on the subject per their updated Airplane Flying Handbook https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/airplane_handbook/media/06_afh_ch4.pdf “Maintaining Aircraft Control: Upset Prevention and Recovery Training”

https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/1011x351/stalltemplate_ee14e3a31f0f891722ee6853b4911a8fac0f3983.png
Their stall recovery template is quite straightforward. If progressing to a spin then use the spin recovery template.

It seems that they have realised that for FAR 23 airplanes, when tested for stall behaviour, the power is not changed until after recovery from the stall.

I was at a flying school recently when CASA asked about this subject and my answer was that we do it per their Flight Instructor Manual – why would I do it any differently. In Chapter 13, for recovery from an incipient spin:

· “recovering by ensuring the throttle is closed and the controls are centralised followed by recovery from the ensuing unusual attitude” but on the following page

· “As soon as the aeroplane has stalled and commenced to yaw take the appropriate recovery action. Increase power, apply sufficient rudder to prevent further yaw and ease the control column forward sufficiently to un-stall the aeroplane.”

CASA does not define an incipient spin however it is required per the Part 61 MOS “execute an incipient spin manoeuvre from the following flight conditions and, using correct recovery technique, regain straight and level flight”.

This correct recovery method must be per the CASA Flight Instructor Manual – "increase power" …… “sufficient rudder” becomes full rudder …. easing the control column forward …… but which of the two CASA techniques?

[Arctaurus]

djpil,

Notice that they focus (2) on unstalling the wing by reducing the AoA - the rest follows once the aircraft wing is below the stalling angle of attack.

The Australian CASA documents are way too confusing and given there is no incipient spin training in a standard syllabus, this really needs to change.

But the Australian regulator of course knows best and knows much more than the FAA (not) :mad:

[Icarus2001]

given there is no incipient spin training in a standard syllabus, this really needs to change.

There is. It is in the Day VFR syllabus.

https://www.casa.gov.au/sites/g/files/net351/f/_assets/main/fcl/download/vfras02.pdf

Have a read.

Then apply sufficient rudder only to stop further turning (AFTER the wing is unstalled)

No. It does not need to be "after" the wing is unstalled. The actions are co-ordinated together.

How about we actually READ what the manufacturer says rather than regurgitating opinions...

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/800x592/img_4691_4bd5c5663ac0573a65c37d28d782db88386a3d73.jpg

[Icarus2001]

At least one incipient spin is also shown here in the CASA flight examiner guide, under PPL test...

https://www.casa.gov.au/sites/g/files/net351/f/_assets/main/manuals/regulate/fcl/flight_examiner_handbook.pdf?v=1532654477

[Clare Prop]

The Day VFR syllabus is long gone. It is now the Part 61 MOS

2.2 A5.2 – Recover from incipient spin This element only applies to single engine aeroplanes.
(a) perform pre-manoeuvre checks for an incipient spin;
(b) recognise an incipient spin;
(c) use the aeroplane’s attitude and power controls to execute an incipient spin manoeuvre from the following flight conditions and, using correct recovery technique, regain straight and level flight with height loss commensurate with the available altitude (simulated ground-base height may be set):
(i) straight and level flight;
(ii) climbing;
(iii) turning.

The POH extract above is for the fully developed spin recovery. Applying full opposite rudder at the incipient stage has already been discussed.

[jonkster]

Problem is the definition of an incipient spin is not clearly stated as far as I can see in the Australian documentation.
Some interpret it has a stall with some yaw present, others as the initial stages of a spin until the spin becomes stable (in the aircraft I use this is around 2 complete turns).

[Icarus2001]

I included the Day VFR syllabus as some people were suggesting that incipient spins have not been taught for some time, which is completely wrong.

[Clare Prop]

I included the Day VFR syllabus as some people were suggesting that incipient spins have not been taught for some time, which is completely wrong.

Yep that came in around 2001, then the MOS in 2014, I've been instructing for 30 years and it's always been in the syllabus and the
flight test.

[megan]

Given the talk about picking up a wing I thought this B-52 bit interesting.Maintain wings level attitude with lateral control as the stall is approached. Fairly large lateral corrections may be necessary. Caution should be used because lateral control capability decreases rapidly as the stalling speed is approached. Rudder may be used to maintain heading; however, during low speed flight, a delay in aircraft response after control input of up to 3 seconds may exist before roll correction develops.

The stall characteristics of the aircraft will vary with wing flap extension and drop tank installation. The following stall characteristics can be expected: With flaps extended and no drop tanks installed, there is little or no stall warning speed margin. Buffet of the flaps when the stall is approached will mask aircraft buffet. At stall, the aircraft will tend to fall off on one wing. This fall-off can be stopped by applying forward pressure on the control column and by using whatever lateral control and rudder is required. As lateral control degrades rapidly at speeds below initial buffet. the use of rudder may be necessary to correct for bank angle.

[David J Pilkington]

Problem is the definition of an incipient spin is not clearly stated as far as I can see in the Australian documentation.Getting there with CASA’s AC 61-16, Spin avoidance and stall recovery training, earlier this year.

The POH extract above is for the fully developed spin recovery. Applying full opposite rudder at the incipient stage has already been discussed.Nope, nowhere does it say in the POH that the extract is for a fully developed spin. The particular example is for a type approved for spinning when loaded in Utility Category. That spin recovery procedure in the Emergency Procedures section of the POH is also applicable to Normal Category where we’re expected to recover (from an unintentional spin) by about one turn. When loaded in Normal Category it was flight tested only up to one turn (so still in the incipient phase).

The flight test crew who do that testing are the same people who write the words for the POH. They follow what it says in the FAR 23 Flight Test Guide which defines a spin as “A sustained autorotation at angles-of-attack above the stall.” So, if in a spin per that definition then use the spin recovery procedure in the POH.

Incidentally, the term “incipient spin” is not used in the FAR 23 Flight Test Guide however it does state that "Most airplanes will not attain a fully developed spin in one turn."

It goes on to state: “Normal category airplanes must recover from a spin in no more than one turn after the initiation of the first control action for recovery. For example, if you are spinning left with ailerons neutral, recover by reducing power to idle, if not already at idle, apply full right rudder followed by forward elevator.” That would be from an incipient spin.

How about we actually READ what the manufacturer says rather than regurgitating opinions...Good advice. That example was for a Cessna A152 so let’s read on from Cessna’s document D5014-2-13, Spin Characteristics of Cessna Models … A152 ….

“For the purpose of this discussion, we will divide the spin into three distinct phases. These are the entry, incipient, and steady phases. ……. in the entry phase, recovery from or prevention of the spin is as simple as normal stall recovery since, in fact, at this point that's all we are really faced with. Coordinated use of rudder and aileron to oppose any tendency to roll should be applied with emphasis on the rudder due to its generally more powerful influence at this point. This should be accompanied by relaxation of elevator back pressure to reduce the angle of attack below that of the stall. Coordinated use of all controls should then be applied to return to normal level flight.

……..

During this incipient phase, spin recoveries in those airplanes approved for intentional spins are usually rapid, and, in some airplanes, may occur merely by relaxing the pro-spin rudder and elevator deflections. However, positive spin recovery control inputs should be used regardless of the phase of the spin during which recovery is initiated.

Briefly, these control inputs should be 1) neutral ailerons and power off, 2) full rudder opposite to the direction of rotation, 3) just after the rudder reaches the stop, elevator briskly forward to break the stall, and 4) as rotation stops, neutralize the controls and recover from the resulting dive.

……..

The final phase is the fully developed ''steady" phase. Here a more-or-less steady state spin results where the autorotational aerodynamic forces (yaw due to rudder deflection, lift and drag differences across stalled wing) are balanced by the centrifugal and gyroscopic forces on the airframe produced by the rotating motion.

……

Finally, it is important, particularly in this steady spin phase, in addition to using the correct control application and proper sequence of control application, to HOLD THIS APPLICATION UNTIL THE RECOVERIES OCCUR. In extreme cases, this may require a full turn or more with full down elevator deflection.”

Pretty clear to me.

[Centaurus]

What's the bet that if you ask any current flying instructor in Australian flying schools the recovery technique they teach if a wing drops at the point of stall, invariably they will say "Don't use aileron but pick up the wing with rudder" and proceed to yaw (skid with excessive rudder) the aircraft to level the wings. I find it incredible that this myth persists of "pick up a dropped wing with rudder" rather than prevent further yaw with rudder.

[Flying Bear]

What's the bet that if you ask any current flying instructor in Australian flying schools the recovery technique they teach if a wing drops at the point of stall, invariably they will say "Don't use aileron but pick up the wing with rudder".

I get what you’re saying, but you’d lose that bet...

I am a current flying instructor, running my own school, and we teach the concept of “stalled stick position” and recovery through AoA reduction as the primary control input. Judicious aileron / rudder input accompanying it. Or... let go the stick - Beggs-Mueller has a dog in this fight!

In order to minimise height loss, set the elevator control just forward of the SSP to be unstalled (but with close to maximum lift) and apply power - thrust reduces height loss as well as AoA.

We have little hope when CASA promote stall awareness by monitoring airspeed as the primary indicator... just check out their newly released poster on the topic. How about learning where SSP is and understanding that forward of that is your “manoeuvre zone”, aft of it is stalled, and that flap for low speed / high AoA manoeuvre is not your friend (SSP moves forward as flap extends, thereby reducing manoeuvre margins).

Working in this space will keep me (and my team) busy for the rest of our careers - unf*#king what the sausage factories, aided somewhat by CASA, have produced!

Funnily enough the best solution is, in fact, the simplest!

[Propjet88]

I respect the stated view that the Stalled Stick Position (SSP) concept is valid for a typical ab-initio training aircraft. However, the stick position at the stall actually varies with weight and configuration (flap setting). It is also not applicable to aircraft that have a moveable stabiliser (such as larger air transport types) where the rate of pitch is controlled by either or both the elevator and or the trimmed position of the stab. The SSP technique may be of value to simplify initial attempts at stall recovery for a student in a light trainer, but under the concept of “primacy” I’d suggest that it is not a technique that should be embedded in early learning.
Fly Safe
PJ88

[Climb150]

What's the bet that if you ask any current flying instructor in Australian flying schools the recovery technique they teach if a wing drops at the point of stall, invariably they will say "Don't use aileron but pick up the wing with rudder" and proceed to yaw (skid with excessive rudder) the aircraft to level the wings. I find it incredible that this myth persists of "pick up a dropped wing with rudder" rather than prevent further yaw with rudder.
"Pick up" the dropped wing, "prevent further yaw". Does it really matter what it's called as long as the person performing the stall recovery does it to a standard that an ATO finds acceptable?

[jonkster]

Pick up the wing is not the same as prevent further yaw. In practice picking the wing up leads to problems (in my experience) bringing people closer to nastier regimes of flight. It is not what should be taught. IMO

[Flying Bear]

I respect the stated view that the Stalled Stick Position (SSP) concept is valid for a typical ab-initio training aircraft. However, the stick position at the stall actually varies with weight and configuration (flap setting). It is also not applicable to aircraft that have a moveable stabiliser (such as larger air transport types) where the rate of pitch is controlled by either or both the elevator and or the trimmed position of the stab. The SSP technique may be of value to simplify initial attempts at stall recovery for a student in a light trainer, but under the concept of “primacy” I’d suggest that it is not a technique that should be embedded in early learning.
Fly Safe
PJ88

Good points. PJ88, but the idea of SSP is to teach Bloggs that fundamentally, stall avoidance / recovery is a function of AoA reduction - which is true in all aircraft. The fact that SSP will move about (for a range of reasons) does not diminish its applicability in training ... But you are correct - in a light aircraft it is basically fixed save for variation due flap extension per my earlier.

Given that the role of flight training is to prepare Bloggs for his first job in aviation, not necessarily the airline (I’m a traditionalist!), I’d offer that techniques applicable to light aircraft are more relevant in early training than those developed for transport category machines...

Certainly, the common nexus is that the instinct must be AoA reduction - SSP as “primacy” teaches that better than the thinking that stalling is more closely aligned with speed - which is what sausage factories and CASA (sadly) seem to espouse...