Power On Stalls, what's the point?
 

I am currently in the US and took a C152 out for a check out. Everything went well until the instructor asked me to do a full power on stall. This is meant to simulate a stall on full take off power and is not tested for in JAA ppl.

Anyway, if anyone was ever to get themselves in this situation, they should not be allowed to fly, it is a totally unrealistic situation to be in.

In the 152 the right wing drops at the stall, and I kept over compensating with left rudder and spinning it the other way. Consequently the US instructor would not check me out, yet a UK instructor at the FTO said as it is not a JAA requirement I should be signed off. But as it is US airspace the instructor wouldn't sign me off. I think its out to the airfieldto practicepower on stalls again today.

Hi Smith,

A bit weak I grant you, but two situations that I can imagine it happening are going around and overbanking in a climb.

HWD.

First of all:What airspace it is in, or whether it is a JAA or an FAA requirement, is not relevant. What is relevant is that the school you are getting checked out on own the aircraft. As the owners, they are entirely free to determine what checkout they need. If I were the owner of an aircraft which you wanted to rent, and I wanted you to be able to juggle 3 apples whilst using the CRP-1 to wipe your backside, you'd have to either learn to do that (I suspect you could probably already do one, or even both, of these, but maybe not together!), or else go somewhere else.

As for power on stalls, if you are deliberately trying to get into one the attitude is so high that it is hard to see a situation where you can actually get into such an attitude. But that is when you are looking out the front. The times when you are more likely to stall will be when you are not looking out the front, e.g. during a turn when your attention might be focused on what you are turning towards, out the side window. Or, as HWD says, during a go-around when you may be distracted by the flaps (which, incidentally, will lower the stalling attitude back to something more sensible, and make it more vicious), or the radio. In that situation, you may well find yourself with the nose much higher (or even much lower) than you intended it to be......

As for the specific problem you're having:I would hope your instructor has told you this already, but pick something ahead (a cloud is probably the best thing if you're going to be raising the nose a fair way - much easier to do these stalls on a slightly cloudy day!), and use the rudder to keep it straight ahead. Don't worry about wings dropping - you can sort that out after recovering from the stall. But if you keep that cloud straight in front of you the whole time the stall warner is going off, through into the stall, and then into the recovery, it should work out fine.

Personally, I don't ask people to do power-on stalls as part of a check-out. Power-on incipient stalls, yes - but the only fully-developed stall I ask people to demonstrate is a clean stall. That's because I was taught to place the emphasis on recognition and avoidance rather than recovery. But don't dismiss this as a pointless exercise - if you can nail these power-on stalls, you will understand, and be able to recover from, clean stalls much much better! :ok:

FFF
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"I kept over compensating with left rudder and spinning it the other way"

-which is why we NEVER teach people to try to 'pick up a wing with rudder'! Just keep the a/c in balance at the stall; recovery technique is to maintain full power and move the control column centrally forward until the stall identification ceases. Then - and only then - level the wings and recover to normal flight.

A lot of pilots have been killed by power-on stalls. Perhaps the most common situation is circling an object on the ground (the girlfriend's house?) and simply exceeding critical angle of attack.

Don't think speed with stalls - think A of A. And the stick is your A of A controller. Unstall the wing with forward stick (assuming an erect, not inverted, stall) as BEagle says. then all will be well.

SSD

A lot of the exercises that crop up during checkouts are intended to allow you to demonstrate to the Instructor your ability to control the aircraft. Whether the exercise is steep turns, slow flight, power-on stalls or even PFLs.

If you mishandle the aircraft whilst demonstrating any one of these manoeuvres then you should congratulate yourself on having identified a weakness in your flying that you were evidently unaware of. Attempting to question the applicability of the exercise is not the right response.

In passing, it is interesting to note how many JAA PPLs struggle with the ground reference manoeuvres required as part of the FAA PPL syllabus. They are not in themselves difficult, but they often reveal flaws in pilot technique that are not demonstrated by going through the standard Uk/JAR instructing menu.

It sounds as though you have a thoroughly useful checkout!

2D

The "departure stall" is a favourite of some American instructors, in my experience.

One asked me to do one in an Archer with a rather rearward C of G.

No thanks said I, landed and found another FBO.

And if you are uncomfortable with what your instructor is asking you to do, I suggest that you consider the same course of action.

So F3G, you are suggesting that if during the course of a checkout, you demonstrate a basic handling flaw, the best course of action is to blame the instructor and find a new one....?

:hmm:

So you stuffed up a manouever and that's the instructors fault how???

Power on stalls may not be a "JAA" requirement, but any instructor worth a fig should make you do it AND you should be able to handle it. There's alot of stuff not in the tests etc. that can still kill you, does that mean you shouldn't understand what they are or how to deal with them?

As for the statement that a power on stall is unrealistic.... Oh really. I'm sure Bookworm could dig up a few reports of people who've killed themselves that way.

As for not checking you out, absolutely correct. You didn't fulfill their requirements, therefore why should you be allowed to take their a/c up unsupervised?

F3G, If the instructor is asking you to do something unsafe such as spinning with a very aft C of G, then you are correct to query it, but why would you go up in a machine knowing that this was the case. Surely you would know what tasks you needed to perform and the a/c was unsuitable in your eyes, so why fly it??

Changing instructors as you think they are too harsh...... Have a look at yourself please....

It may not be a JAA requirement in order to pass one's Skills Test but surely you must have covered these in your training? If not then it would be a good idea to go and do some as they are potential life-savers - I hated doing them, they scared the hell out of me, but that may well keep my mind a little more focussed, e.g. as in the case above, when circling someone's house.

Can't remember a single club/type checkout that didn't include a power-on stall, and in fact the first time I did one in a C172 I went into a beautiful incipient spin (the instructor was only slightly reassured that I recovered from that instinctively!). Certainly my last one (T67) included one.

Tim

Cloud69,

I don't think it is in the JAA syllabus. I do see Smith's point. I think it is a little artificial, but I can see that it is important to understand how the relative control sensitivities cannge with a tip stalled wing and prop wash over the tail.

I seem to recall my instructor demonstrating one in a 152 to show how to get it to spin.

What sort of thing would you be asked to do as a ground reference manoeuvre?

tKF

Smith, I wasn’t there so I don’t know for sure but I would imagine that although the instructor was concerned in particular about your power on stalls, he would have also been concerned about your general handling abilities. You may have seen some argument on these pages about US students requiring extra hours with an instructor when returning to the UK – well the reverse is true insomuch that either way you have to convince an instructor who doesn’t know you that you are safe to be set loose with his/her clubs aircraft.

The fact is that the instructor doesn’t want you to bend the aircraft or heaven forbid kill yourself. Be patient, extra instructor hours will benefit you and for sure the instructor and aircraft is cheaper in the USA than in the UK.

The advice given by BEagle is the best you are going to get

quote:
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-which is why we NEVER teach people to try to 'pick up a wing with rudder'! Just keep the a/c in balance at the stall; recovery technique is to maintain full power and move the control column centrally forward until the stall identification ceases. Then - and only then - level the wings and recover to normal flight.
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The only thing that I would add is that you should move the yoke gently forward. I did fly with somebody who was having the same problems as yourself and I did identify that he was not keeping the ball in the middle at the approach to the stall. Certainly it should be easy with practice to keep the aircraft level in the stall using only the rudder if you are not struggling to keep the aircraft level with the ailerons when the stall occurs(but don't try this without an experienced instructor on board). It is essential that you fly the aircraft with the ball in the middle all the time since an uncoordinated stall or turn at low speeds can have some odd if not predictable and potentially dangerous consequences!

The original comment referred to a 'full power on stall'. If that means recovering from a fully-developed stall entered with full power, then it is perhaps unsurprising that he had difficulty as he was probably totally out of his depth!

Anyone should find demonstrating recovery from a stall in the approach configuration reasonably straightforward - but normally the recovery is required at the incipient stage only. We demonstrate the fully-developed stall in the approach configuration during Stalling 2, but it is not a requirement for any JAR-FCL LST/LPC or Skill Test.

A full power stall might be demonstrated during training to the fully-developed stage, but I wouldn't expect a PPL student to practise it. Also, due to the high likelihood of an incipient spin, I would require the a/c to be in the utility category for such an aggressive manoeuvre.

There is a balance between safe handling skills and risk avoidance. I don't see the relevance of anyone being required to demonstrate recovery from a fully-developed full power stall unless they are hiring an a/c for aerobatics.

What was the ground brief like - and was the requirement discussed properly?

People unfamiliar with the FAA and its interest in "Power On Stalls", may be interested to read this document:

http://av-info.faa.gov/data/practica...s-8081-14a.pdf

Partly for clarity, and partly to avoid disputes when and if people are failed for their various FAA licences, these booklets are published, one per licence or rating. The describe in detail the manoeuvres that an examiner can ask an applicant to perform, along with acceptable performance criteria.

The Power On Stall is covered on page 55 of the PDF file (document page 1-28). In lower performance aircraft, these will normally be performed at climbout power setting (25" and 2500), the applicant having previously slowed the aircraft down with a marked power reduction, before simultaneously applying the requird power and pitching up to the stall. In aircraft such as the 152, it is not unusual for the exercise to be accomplished at full throttle.

You'll note, with reference to BEagles comments, both the power settings that the FAA requires, and the desired recovery technique (point 6). As "smith" reports his performance, he would have failed an FAA PPL checkride.

In reply to the Kentish Fledgling, the Ground Reference Manoeuvres can also be found in the PDF, page 49.

2D

"....simultaneously applying the requird power and pitching up to the stall. In aircraft such as the 152, it is not unusual for the exercise to be accomplished at full throttle."

Such deliberate mishandling seems totally inappropriate and positively invites an incipient spin.

Hence my comment about ensuring that the a/c is in the utility category; it should also be cleared for intentional spinning!

The CAA/JAA preference for stall 'awareness' seems considerably safer and more realistic to me.

Thanks, 2Ds - interesting document to have. Do you know if there's an equivalent CAA / JAA version online?

tKF

That risk certainly exists, although the FAA normally requires recovery to be performed at the higher airspeed of either Buffet, or Stall Warner. The aircraft is not normally flown to the actual stall at PPL level.

The thing being checked is the candidate's ability to enter the manoeuvre in a controlled manner (with particular reference to the configuration and the ball), and to exit it with the appropriate control inputs in the correct sequence. Not for nothing do we find spin awareness as the next section on the same page of the Practical Test Standards document.


2D

My instrutor had me do TOGA stalls for my JAR PPL. I will have to ask him to confirm if they are on the syllabus.

Nothing to them so long as you are not doing them in real situ.

Half a dozen years ago I was asked on behalf of AAIB to do a bit of flight testing for them. They had had an experienced pilot (although not on that particular type) go from a full power climb fatally into the ground with high speed and bank angle. Nobody could (initially) work out why. The certification standard against which that aircraft was approved hadn't required full power stalls to be evaluated.

We had a suspicion that the pilot had probably not judged the pitch attitude correctly (this type had a very low cockpit coaming compared to what he was used to), and might have entered a full power stall. This was an unknown area of flight in that type, so I went to take a look at it.

Unlike an idle stall which gave plenty of warning and no wing drop, at full power this gave no warning, and the aircraft went straight into incipient spin - disconcerting when I found it the first time.

We theorised (you can never be sure, but I'm convinced) that the aircraft went from a full power stall into a spin, which self-recovered into a spiral dive (a common characteristic of small aeroplanes). Given this was at about 500ft, he had little time or height to play with - so he died and the aircraft was destroyed.

Had that pilot been more familiar with the aircraft (he had about 3000 hrs I see from my notes, but nothing on type and only a few hours on similar types) and/or power-on stalls, he would have probably recognised the impending power-on stall and recovered, or have recognised it when it occurred and responded in a manner that did not cause a spin/spiral dive/ground impact.

We quietly changed the rules at that time to include assessment of full power stalls during certification of similar aircraft.

So, my vote is that practicing power-on stalling is necessary and appropriate (then again, I always have anyhow, and have never had a problem with FAA checkouts).

Anyhow, stalling is fun - where's the problem :} . I had a very happy morning this morning practicing various stalls with an instructor to get me back into currency, and have no problems with it at-all. (Although comparing notes over a coffee afterwards, the FI had about 1/3 my hours - I'm getting old :{ )



I recall a checkout instructor once who made me fly a very precise figure-of-eight around a couple of convenient landmarks. Very very good discipline, I've practiced it occasionally since and it's a useful handling practice, particularly if there's significant wind.

G

Interesting though your experience is Genghis, we shouldn't lose sight of the original observation at the top of this post.

The aircraft concerned was a Cessna 152. Like the vast majority of aircraft in the GA fleet, the 152 is certificated under FAA Part 23, and most foreign certification (including our own) is substantially on the basis of that testing.

Part 23.201 defines the stall tests which the aircraft must be put through for type approval, and it will be of no surprise that power-on stalls at full power are specified as part of the test program for aircraft such as the 152. A requirement for a satisfactory pass of 23.201 is an early and pronounced stall warning prior to a stall.

There should be no suggestion that a C152 requires the extreme skills of a test pilot in order to perform a power on stall without the risk of a spin. Indeed, tens of thousands of FAA pilots got their wings in 152 and all will have had to demonstrate proficiency at the manoeuvre.

2D

OK - full power stalls recovering at the first stall warning (i.e. at the incipient stall) I can accept. Deliberately continuing to the fully-developed stage might be reasonable for certification purposes, but the average pilot should certainly not be expected to take a full power stall to the fully-developed stage.

Later edited to add: The only time I have deliberately induced a full power stall in recent years was when checking the rigging of an a/c after it had been susbtantially rebuilt. Even then it was only to the incipient stage at a 1 kt per second deceleration rate - certainly not a deliberate pitch to the full stall.

I agree with Beagle here, while it is important for a pilot to be familier with all aspects of handling the aircraft they fly there is is little reason for psuhing the envelope to the limit. Power on stalls to the warner or buffet make sense but not really full developed?

On frequent occassions I have full power stalled my 152's and excercise has a number of times ended up in a spin. Fun but I think for the unwary it could be a problem especially with spinning not being taught as part of the PPL anymore.

Personally I love spinning my aircraft for the entertainment value but prefer to do it intentionally so I can tie things down first!!

2 Donkeys and Say Again Slowly

The Archer is not cleared for spinning and to attempt a full power stall, with the CoG near the rear limit is, in my opinion, extremely foolish.

The aircraft could easily enter an spin and be unrecoverable due to the CoG. Remember, it is not cleared for intentional spinning, so spin recovery is test pilot work and I prefer to leave that kind of stuff to John Farley and Ghengis ;)

SaS, you are assuming that the instructor briefed the manouvre requested, which was not the case.

He also asked me to change fuel tanks at the hold, following a landing and before the next departure, without a run up check and got annoyed when I insisted on doing a power check before departure, saying it was a waste of time.

He was accident waiting to happen, in my opinion, and I must say not in line with my experience of most US instructors, who I've found to be professional in approach.

And as a PPL with a few hundred hours stick time (and over 200 on the PA28), I know enough to recognise instructors who do not act professionally.;)

Also, 2 Donks, fine to quote the FARs, but bear in mind that there are not a panacea for all evils; Have you ever read Dick Collins feelings about the past requirement for flying a light twin, on one, low level, around the minimum control speed?

He claims a lot of people died because of this requirement.

Actually my contribution was going to be to relate the following: the only time I recall triggering a stall warning horn in a situation when I really didn't intend to was in an unexpected go around in the Mooney with full-power on and full flap deployed.

I also remember doing some training in a 152 (I think it was a club checkride) with the then Chief Pilot of Marshalls. He suggested that we try a full power stall. As I was setting up for it, I asked "So what am I expecting to happen then?". He turned to me and said, in his inimitable deadpan tone, "I have no idea, I've never tried one before."

I also agree with BEagle that there seems to be no reason to take such an exercise further than the incipient stage.

F3G

May I say that I think you are too tied up in your own story and not in that of the original poster.

He was in a 152 with, so far as we know, a C of G that was perfectly acceptable. By his own admission, he mishandled the recovery from a stall, and was failed by the instructor.

Your advice was to swap instructors, and I disagree with you.

It is as simple as that.

Meanwhile, I'll keep on with the FARs and the PTS. Bombproof they are not, but they are far clearer than the corresponding lack of documentation published in JAR-land.

In passing, I reckon it could be a mistake to talk about your experience as a way of fortifying your position.


2D

:) :) :) That sounds like the people I trained with!

Seriously though ... knowing that the only stupid question is the one I don't ask ...

I sure I recall being in a little aeroplane with power on (don't recall whether it was full or not, don't recall the flap setting either, er, not very good at this am I) and the stick back as far as it would go and the nose pointing at the sky and the thing simply refusing to stall. In that the warner was blaring away, but the nose didn't drop and a wing didn't drop and whilst we weren't making a lot of forward progress we weren't making much downward progress either. Sure the wings must have been at least partly stalled, but the thing was still flying after a fashion and we decided it wasn't a "stall". So, as the thing wouldn't "stall" in this configuration with this power setting the instructor decided that it was reasonable that I'd failed to demonstrate a recovery from the non-existent stall!!

So, the stupid question is:

Are there ranges of configuration and power setting for particular aircraft where this behaviour is expected - it stays upright, mushes along vaguely forwards, nose doesn't drop, wing doesn't drop, no more elevator to bring into play?

What makes you think that? I don't think there's a certification requirement that there must be enough elevator authority to stall in any configuration, is there (Genghis?)?

No such requirement in FAR 23.

2 Donkeys

I don't want to get into an argument, but you said...

Now that wording is ambiguous and I took it as personal criticism, but apparently it was not.

With all respect, it was not as simple as smith being failed, since we also know that another instructor contradicted his instructor.

I would not expect that kind of contradiction in a professional FBO or school. Why should one instructor disagree with another to a student? Who knows, but I can understand why Smith is feeling confused and disconcerted.

He (or she) is also paying for professional service and does not deserves mixed messages.

If this situation makes smith feel uncomfortable enough, then let him consider finding another school or instructor.

If the same mishandling occurs again, then the result will be the same.

Several times in the past, when I have asked a PPL on a check ride to go around from landing config without previous briefing, he has pitched up before adding power. This is a fact, also if an a/c on the runway is a bit slow on taking off, the tendancy for a pilot on finals is to slightly level off while looking at the a/c on the ground, setting up for a power on stall. After a sneaky assesment of a pilot on a checkride, I would at a safe hieght talk him/her into a power on climbing stall with 20flap on a C150, and I have always been thanked for the excercise. Pilot who say "Iwould never get in that situation" frighten me.

That is a neat summary of my concern Croqueteer.

2D

2 issues here?

(a) Differences between UK and USA training syllabi.

(b) Differences between individual instructors performing training and checkouts.

As far as (a) is concerned , perhaps a CAA authority could explain why ground reference manouevres and departure stalls are unnecessary in UK/JAA PPL training. Likewise, perhaps an FAA authority could explain why they are considered essential in the US. Then we can each make a more informed judgement.

As far as (b) is concerned, that debate could last quite some time as there are so many aspects of flying technique which lend themselves to personal interpretation/preferences - see the instructor forum.

F3G, I've taken Archers into full power on stalls, never ever noticed any Cof G issues! Sure you mean Mr Pipers Archers?

Punch ups aside, How did you get on with the stalls smith?

A fine can of worms you opened here:p

Sensible

Were you in the utility or normal category?

What was the c of g?

Would you still do it with a 90kg observer in the rear seat and three heavy flight bags in the luggage compartment?

The Archer is a very docile aeroplane, but it will bite if provoked enough.

FAR-23 defines the stall as the point at which the aircraft departs controlled flight or the pitch control is on the stop. Therefore by definition, the aircraft can stall at any weight and CG condition - it's just that the characteristics of the stall may change.

2D - you missed my argument a bit. I was not arguing that all pilots should be taking an aircraft to a fully developed power-on stall (although I'm as-yet unconvinced it actually does any harm in a sorted aircraft). No, my argument was that a power-on stall can be achieved inadvertently by a very experienced pilot (and thus probably an inexperienced pilot too), and that it's clues and warnings are not identical to those of of an idle stall. Therefore a pilot should be made fully aware of what it looks like and how to recover safely from it. I wouldn't have a problem with that involving just taking the aircraft to incipient if the stall characteristics are particularly nasty.

In that context, I think that the FAA instructor was quite right to refuse to sign off our original poster if he couldn't deal with the power-on stall - although it might have been more polite to turn the sortie into a bit of instruction in the subject and then do a second checkride a little later. I'd particularly bear in mind that this was a 152, which takes some pretty gross mishandling to spin - even from a power-on stall.

G

Windy, I've yet to meet an aeroplane that knows the difference between UK and US training.

F£G the answer is I would never fly an aircraft which was loaded outside of the Cof G limits whether it was to practice stalls or otherwise! Providing that the aircraft was within the manufacturers CoG limits, I cannot envisage a problem (and we are talking training spam cans here)

Sensible

Fair enough about flying out of limits, but that wasn't the case, the aircraft was just in w&b. I know that, because I was doing a BFR and had calculated the numbers and shown them to the instructor before departure.

So, say the aft limit was 93" and the aircraft was at 92 and a bit and 10lbs under gross, how would you feel then?

IF you inadvertently got into a spin (IF) from a full power stall (and the pitch up angle to stall an Archer at full power is pretty steep), how comfortable would you feel about recovering in an aircraft that was not certified for spinning?

So it's a matter of risk judgement isn't it? The Archer certainly isn't a hot ship, so you might well get away with no spin or recover from the spin.

But with a very rear c of g, previous experience in PA28-140s, which were cleared to spin within a very narrow forward c of g envelope, would not persuade me to take the risk of encountering a flat spin.