Forcing benign aircraft to stall to make a point.

[Tee Emm]

I apologise to the Moderator for posting this initially on Flight Test forum but it only generated one reply and afterwards I thought it would be more suitable on this forum

Forcing benign aircraft to stall to make a point.
The Australian Civil Aviation Safety Authority (CASA) Day VFR Syllabus flight test form requires a candidate for the General Flying Progress Test to be tested for competency at stall recoveries and also recovery from a stall with wing drop.

Many light training aircraft have benign stall characteristics and this includes no indication of a wing drop. Indeed to induce a wing drop at point of stall it takes gross control movements to the point where it would be doubtful if a student would ever be placed in such a situation. Some instructors therefore will artificially induce a wing drop by raising the nose sharply and applying firm rudder in the direction of the desired wing drop then hand over control for the student under test to recover.

My point is this: If the aircraft type on which the test is conducted does not stall in the classic manner (such as sudden nose drop?) because of modern design, is this sufficient to adequately assess the students ability to recover with minimum loss of height. Along the same argument, if the wing simply does not drop, then forcing a substantial wing drop artificially by aggressive rudder and asking the candidate to recover - is this a valid "solution" so a box is ticked that he is certified competent to recover from a wing drop at point of stall?

If at a later date the student is to convert to another aircraft type, should he be also tested by an instructor for stall recovery competency on that new type? This is because the stall characteristics may be different from the type he was originally tested on for his GFPT.

Some PPL syllabus require a student to demonstrate skill at stall recovery from a gliding descending turn. To get into that situation where a stall occurs requires significant or even gross mishandling which could overstress the airframe. Is it wise therefore to expect the candidate under test to try to obtain these gross atttitudes to force a stall?

In the "old" days some trainers such as the Chipmunk, Wirraway and even the Tiger Moth easily displayed the classic stall symptoms where the nose and one wing could drop sharply. Maybe the rigging was incorrect but it happened and it didn't take much to cause the aircraft to enter an incipient spin if stall recovery was botched. But some flying school syllabus of training today still assume all aircraft display the "old" stall characteristics. And if their aircraft are benign, instructors fix that minor problem by deliberately forcing these aircraft into impossibly unrealistic attitudes to tick the required boxes.

Your thoughts would be greatly appreciated because I for one, feel account should be taken of the much safer stalling characteristics of current flying school trainers and that forcing stalls is too artificial and simply wrong technique.

[Oktas8]

You're right about modern aircraft having very benign stall characteristics. I teach instructors not to say "if you apply aileron at the stall it will give you a wing drop", because in most modern aircraft, ailerons remain fully effective right into the stall. But the old techniques must still be taught IMO because it is assumed knowledge when converting from one type to another. It's not possible to assume that the stall recovery will be re-taught when converting onto a different (older?) type. Also, what we learn first we remember best...

Some instructors therefore will artificially induce a wing drop by raising the nose sharply and applying firm rudder in the direction of the desired wing drop then hand over control for the student under test to recover.

Sounds a bit scary, but that's what I did until a more senior instructor showed me the error of my ways. Just relaxing the rudder input at the stall will generally suffice to generate a wing drop, and if it doesn't then I will just move on to the next test item.

Regarding the stall in a gliding turn, I've seen students on a pre-briefed FLWOP exercise get firmly into the stall-warning regime during the turn onto final approach with some flap applied. There is no risk of overstress (too slow) but also no apparent awareness of attitude change required when turning in the glide with flap selected. It's all too easy, even in the more benign training aircraft like a late generation Piper Warrior.

I support using practical applications of the stall recovery, but I do not support removing it from the syllabus. Not until most light aircraft are genuinely un-stallable, not merely un-stallable by a competent pilot on an average day.

[RTN11]

I wish they would make a new batch of PA-38s as these are specifically designed to demonstrate the stall characteristics you are describing. Most schools operate PA-28s or C172s, where you barely even realise you are stalling, let alone see wing drop. Even with power on and flap selected, it is still hard to induce a wing drop, so the student never really learns to recover from this dangerous state.

[S-Works]

so the student never really learns to recover from this dangerous state.

One could argue that the frequency that people encounter aircraft that will demonstrate this state is increasingly rare and therefore when they actually convert onto a type capable of this 'dangerous state' that we teach appropriately at the time rather than trying to simulate it in something else?

[NazgulAir]

One could argue that the frequency that people encounter aircraft that will demonstrate this state is increasingly rare and therefore when they actually convert onto a type capable of this 'dangerous state' that we teach appropriately at the time rather than trying to simulate it in something else?
You can argue that, but something you learn during basic training is a skill you take with you for the rest of your flying life, and it is a usefull skill on any aircraft you may encounter later. It may stop you from developing certain bad habits that are difficult to unlearn.

[Tee Emm]

new batch of PA-38s as these are specifically designed to demonstrate the stall characteristics you are describing.

If you mean specifically designed to drop a wing at the stall; then is that really true? I would have thought that the airworthiness authorities have a set of safety standards when it comes to accepting aircraft for the civil register. A significant wing drop at point of stall would surely be reason for denying Certification. After all, this could cause wing damage if the aircraft is held off high and a wing drops as part of its deliberate design. Can't see the insurance industry being too happy about that feature

[mad_jock]

they wern't designed per say to drop a wing.

Its just when the pilot does something stupid and against what they are taught the wing will drop. If you stall them correctly as per the book they will do it wings level with no wing drop (but they are all old now and each has its own characteristics). But put a hint of incorrect control input and the wing will drop, but not in a dangerous manner. All the cessna pilots poo themselves because it just seems harsh compared to the mushing none event they are used to.

[S-Works]

You can argue that, but something you learn during basic training is a skill you take with you for the rest of your flying life, and it is a usefull skill on any aircraft you may encounter later. It may stop you from developing certain bad habits that are difficult to unlearn.

Sorry but I don't agree. The least used skills are the most quickly lost. Learning something once and then never using it again for years is not a skill you take with you for the rest of your life. Personally I think it better teach the skill when it is actually needed and can be practised to stay current.

[mad_jock]

Nah thats bollocks IO

Intial skill will be with you the rest of your life which is why 1-13 are so inportant in intial training.

You can stick someone on a bike 20 years after they have learned and they will still be able to ride it.

Its once dick head instructors go down the re training route that confusion rains.

Getting taught correctly the first time in a proper aircraft is the important factor.

[gunshy67]

Dear People,

Aviation has progressed over the years and there are sequences I have been taught in my youth that are no longer relevant.

That is not to say that wing drop or, heaven forbid, spinning, should not be taught............but in an appropriate aircraft only.

It used to be that training aircraft had wing "wash-out" to try and prevent wing drop. Also leading edges wedges were fitted - and in those aircraft you did not need to force entry for a wing drop.

That produced the "rudder technique" with a collateral requirement to keep the ailerons neutral otherwise the situation would be aggravated. (Auto Rotation)

But now with improved design in trainers the stall characteristics are such that the wing root will stall first and the ailerons retain some measure of control - i.e. not stalled.

So now here is my punch line...........you train for the aircraft and the characteristics it has. You don't force it to do anything else outside for what it was designed. Other aircraft display differing characteristics and that is what you train for ...........a specific aircraft.

So what is the standard stall recovery...first don't. Then if you do this is the recovery FOR THIS AIRCRAFT.

Happy Hi's to all.

[Oktas8]

C172 and PA28 types are not immune from unintentional wing drops, although full credit to the designers for making them as safe as a conventional aircraft can be, with or without leading edge wedges. There is such a thing as a Standard Stall Recovery because it need not vary for any (light) aircraft. Not to be confused with the non-existent "standard spin recovery"!

Other aircraft display differing characteristics [in the stall] and that is what you train for ...........a specific aircraft.

I thought the RAAF teaches a standard stall recovery in basic training? Now complex aircraft such as fast jets or transports, fair enough, I wouldn't know what is best.

Regardless of what we all think is the best way to train in light aircraft, the way training is actually done in GA is to minimum cost with plenty of shopping around for the easiest ride. Hence the very conservative approach to PPL licensing that ICAO suggests.

Cheers,
O8

[Machinbird]

One of the more common ways to give an aircraft benign stall characteristics is to limit how much up elevator is available. Aircraft are very sensitive to this setting, and a mis-rigged elevator is all it takes to make an old fashioned stall.
Improbable, you say? I remember many decades ago when I was a solo student shooting touch and goes in a C-150 that had just had maintenance. The elevator hit the up stop prematurely during the full flap flare. A burst of power got the nose up and landing was uneventful. Cause was an upside down elevator bellcrank! Admittedly the opposite polarity problem but indicative of what can still easily happen.

We are not driving aerial cars. They are airplanes, and the sooner students learn that they can bite when abused or in unusual situations, the better. Knowledge is power.

[S-Works]

Getting taught correctly the first time in a proper aircraft is the important factor.

And that is exactly the point of this discussion. There are not many aircraft around anymore that you can demonstrate it which goes back to my point. You cant artificially contrive something and expect people to learn from that. So as I said you have to make sure that they learn it when appropriate.

[sablatnic]

I was taught flying in a C172, which had a twisted wing, and had to fly with left tank full to cruise "almost straight", just before the right tank was empty. Stalled as if the left wing was chopped off with an axe. Great for teaching, that although the planes looked alike, they didn't all fly the same.

[Tee Emm]

I was taught flying in a C172, which had a twisted wing, and h

Ye Gods! And I thought it was only Australian GA that was crook. Did anyone realise that C172 was so un-airworthy as to be criminal.

[sablatnic]

I don't know about un airworthy. I personally didn't consider it unsafe, just entertaining, but then again, my background was modelflying, with all kinds of lopsided things. I was prepared for the wing drop by its manners when lifting off, and almost kept the wing from dropping, with a large dose of rudder, much to the amazement of my instructor, who had asked to have just this plane, since we were going stalling, and who before the first stall, had asked me to just make a nice, straight stall.

[Tee Emm]

So now here is my punch line...........you train for the aircraft and the characteristics it has. You don't force it to do anything else outside for what it was designed. Other aircraft display differing characteristics and that is what you train for ...........a specific aircraft.

Precisely. And that was the point of the thread.

[GunRack]

Tee Emm

Is a wing drop or nose drop displaying the worst situation regarding stalls that you would want to recover from? If the aircraft drops a wing and or nose with low airspeed we think to ourself its stalled, now I shall recover. Stick forward until the buffet stops whilst applying full power with rudder to stop the yaw and all should be well with the world.

The Scottish aviation Twin Pin being an old girl does not have the luxury of a stall warning system and has stall characteristic so benign you would think what’s the point in stalling it. Many times I've seen a student sat there with the nose high in the air and the speed below that at which she should have stalled still trying to induce a stall. After a while a gentle reminder to check the VSI which is now showing a stable 1500 fpm earthwards, now they recover. If they were to get in to this situation close to the ground, the first they would know about it would be when the aircraft hits in a wings level nose up attitude. Good night and thanks for playing.

Others I have taught on, the twin otter for example with 20 flap and a small amount of power would do the same. If it were not for the stall warning system (which can malfunction) the result would be the same.

The benign stall, no buffet, no wing or nose drop and possibly no stall warning is in my opinion more dangerous. I always teach to look for the signs of a stall outside of the aircraft telling you she's stalled. High nose attitude, marked rate of descent, low airspeed, perhaps a standard recovery might now be in order.

As for the type specifics, not all aircraft stall the same but they all go downwards and the airspeed will be low. A standard recovery should get you out of it (in most cases).

BRgds
GunRack

[NazgulAir]

After a while a gentle reminder to check the VSI which is now showing a stable 1500 fpm earthwards, now they recover. If they were to get in to this situation close to the ground, the first they would know about it would be when the aircraft hits in a wings level nose up attitude. Good night and thanks for playing.

The rapidly winding down altimeter should also provide a clue. :eek:

[GunRack]

Nazgul

Couldn't agree more. Tend to use the VSI to demonstrate as this quantifies the marked rate of descent.

Best Regards
GunRack

[biffo28]

Bose-X is correct, skills requiring hand/eye coordination are quickly lost if not practiced regularly. The "riding a bike" analogy is a very poor one as that is one of the few exceptions to the rule, hence the often used phrase - "its like riding a bike etc etc".

As for "Bollocks", just look at Mad Jocks post!

[Biggles78]

Most schools operate PA-28s or C172s, where you barely even realise you are stalling, let alone see wing drop
With the PA28-140 try, 1,500rpm, 2 notches flap, ease back gradually on the column to wash off speed and maintain height. At 60kts, a smooth and rapid back pressure movement on the control column has in my experience produced a left wing drop on most ocassions.

On the PA28-151 and above (tapered wing), if the fuel is fairly evenly balanced in the tanks, the nose drops with the wings remaining level unless you give it a helping hand with some (left) rudder.

C172, didn't fly them enough to develope the appropriate technique.

[mad_jock]

People get rusty they never loose it completely.

My extreme example of this was a NPPL student who had last flown while dropping supply's into Italy for the partisians in a Halifax bomber in WW2.

Turned up aged 82 and wanted to start flying again. To be honest if it wasn't for the duty of care thing with at least having something on paper about doing emergency training and not having a valid medical I would have been quite happy sending him solo after an hour and half.

In the last year I renewed my SEP after it had lapsed by 4 years. Did the test from the RHS no probs after an hour practise.

If the intial training planted firm foundations of knowledge and application its still there but never gone.

Another example is when I need some quick cash I go lorry driving in 40 tonne artics. Sometimes its 3-4 years between getting behined the wheel. Bending a 40 ft trailer into a tight loading bay is way more difficult than landing an aircraft. Yep you do miss judge it the first couple of times and have to reset which is not something we have available while flying (well we do we just go around)

I haven't driven a car for 8 months either but I won't be stalling and crunching my gears the next time I get in one.

[S-Works]

Indeed, people do get rusty but never truly forget memory skills. However for a skill to become a memory skill it has to be practiced over 500 times according to current learning theory. Demonstrating a contrived stall configuration a couple of times does not constitute a memory skill.

[mad_jock]

I hadn't stalled an aircraft in 5 years when I did that SEP test. BUt then again it seems bloody obvious what you need to do to cure a stall to me.

Again with students the engineering/physics types don't really need much pointing in the right direction, you just explain whats happening and its logical what the "fix" is.

Most commercial pilots will only do stalling once every 3 years depending on there LPC cycle.

[S-Works]

MJ, we are going off at a tangent here. We are not talking about the skill of stalling, we are talking about forcing an aircraft into a contrived position that it would not normally demonstrate.

I agree that the standard stall recovery is practiced frequently enough for most people to be able to remember and respond to it. What I don't agree with is using an aircraft type that has a had a particular characteristic designed out of it to try and demonstrate something irrelevant.

Better to teach it in an aircraft where you are actually likely to encounter the situation.

As for stalling at work, we demonstrate it every 6 months as part of the OPC/LPC cycle. I tend to have to demonstrate it rather more!

[mad_jock]

:D yep full agree with that statement.

Mind you that old halifax pilot never had a wing drop during stalling training. I never felt the need to induce one. I just sat in the RHS and watched and learned from the old master at work. It should have been me that was logging dual not him.

[Oktas8]

Hi again all,

Better to teach it in an aircraft where you are actually likely to encounter the situation.

That's something we can all agree with as an ideal to work towards.

But instructors usually don't get to choose which aircraft type to train on, and they don't get to modify the CAA/JAA/ICAO syllabus they're training from. So it's necessary that they learn to do the traditional thing - which is, to learn to demonstrate a wing drop stall without playing silly buggers with the rudder.

[Centaurus]

So it's necessary that they learn to do the traditional thing - which is, to learn to demonstrate a wing drop stall without playing silly buggers with the rudder.

Easy. Pull the aircraft into a very steep turn and close to the stall introduce a modicum of top rudder and watch how the steep turn reverses and goes over the top the other way. Relax backward pressure and rudder and it straightens up.

[frank booth]

You dont need to use rudder to induce a wing drop. Full power clean/flaps select a suitable pitch attitude to get the airspeed to steadily reduce and and get the student to do what most of um do anyway, thats just rest their feet on the rudder pedals! The prop wash does the rest, and away goes the wing. Two things achieved - how to recover, and the importance of keeping that little ball in the centre. Works in pa28, c152/172....

[FlyingStone]

Two things achieved - how to recover, and the importance of keeping that little ball in the centre.

How will you demonstrate adding of full throttle for stall recovery if you already throttle in full position when the aircraft reaches stall? And also - how would you ensure that the student adds a bit of right rudder (to compensate) for adding full power at low airspeed? It seems all you have to do for stall recovery according to your teaching techinque is to release the yoke/stick or push it slightly forward.

Besides, I don't really believe in demonstrating full power stalls in C172 - agreeably, stall during high-pitch atitude climb (Vx) would be in this configuration, but C172 seems to be too stable to demonstrate it corectly. In fact, the last time I did try to stall C172 with full power it was still climbing (not stalling) with pitch attitude far exceeding the one in Vx climb.

Someone should really open a factory of new Tomahawks :ok:

[frank booth]

Unusual attitude recovery, Power - Bank - Pitch. If the power needs to be full and its already there, consider leaving it as such. Why not demo full power stall in a 172? It's full power for the take off and climb out, which is where statistics say the most fatal accidents occur. Agreed it is a high nose pitch attitude, but more realistic than trying to induce a wing drop with an abrupt pitch up and boot of rudder. It does work nicely, try it....

[Oktas8]

The OP mentioned assessing wing drop stalls, which I believe is done pre-PPL in the Australian GFPT.

Therefore, there are some good reasons why it is inappropriate to stall at full power. One was mentioned above, another is that it is much more likely to scare the student, another is that it does require a really really high nose attitude (from a late model C172 with 2 pob - I've tried it.)

Much later in the syllabus, sure, why not? Expands the student's horizons and all that.