Sensible

Indeed, Chuck's input, as always, would be valued.

So many techniques, so little time
 

I've been instructed on several subtely different stall recovery techniques during my travels, spanning powered aircraft and gliders.

Ultimately the recovery technique to be used depends, I suspect, on the nature of the stall and the point at which it is recovered (incipient or fully developed). Would I be right in saying that a stall recovery is, in the purest terms, to ensure that the angle of attack is reduced to within the critical angle and that laminar flow is restored over the wing?

In which case, if recovering from a power-on stall, wouldn't pitching to the horizon be sufficient, provided the angle of attack had been reduced? My logic being that the chemical energy of the fuel is then being converted into the kinetic energy (airspeed) required to promote laminar flow. This holds true if in a power-off (or unpowered) stall, as then you would be relying more on gravity to provide the airspeed required to restore the airflow.

Curiously, when I was converting onto gliders (which happened after I learned on power), I pitched forward during stall training with the CFI.

"What are you doing?" he asked.

"Breaking the stall," I said to Sir in the back. He then explained that I had been a little more heavy than I'd needed to be in the process. I was subsequently taught to progressively, smoothly and more slowly move the stick forward, until the wing was flying again. The reason being that this minimised height loss - always the aim when soaring.

It occurred to me that gliders pitch down by just enough to acheive the aim, because they have no other way of turning potential energy into kinetic (hence airspeed). So, with a powered aircraft, providing that the AoA was sufficiently reduced, wouldn't a pitch to the horizon be sufficient? Certainly that's what I was most recently instructed to do as part of my pre-commercial 'polishing'.

It'd be good to get some feedback from those with more experience under their belts...

The exaggerated pitch attitudes taught by some for stall recovery are perhaps germane to this discussion.

We teach:

STANDARD STALL RECOVERY

1. FULL POWER AND CONTROL COLUMN CENTRALLY FORWARD...

(But not until the windscreen is full of ground, ONLY until an attitude is reached at which whatever it was that told you you had stalled no longer does so! That is probably only very slightly below the horizon; the shove-then-add-a-bit-of-power taught by some is TOTALLY INCORRECT!!)

2. LEVEL WINGS

3. RECOVER FROM ANY DESCENT

4. AND AT ALL TIMES MAINTAIN BALANCED FLIGHT!!

This works for any stall, the only difference with stalling in configurations other than clean is that flap should be deselected as for any normal go-around - once initial recovery has been completed.

BEagle

Using your techique, what approximate height loss would you expect in a PA28-140 (say at 1900lbs), from a power off stall with land flap?

I am curious to compare your view with my handling notes/instructions from my PPL training in the last century, to see if I've been using the "shove and add a bit of power" technique!

If so, I shall repent immediately.

Reading the US AOPA accident report again they quote the PA28-181 POH as having a maximum hehgt loss during stalls of 350 ft - this sounds quite a lot to me :rolleyes:

When I posted this question never did I imagine it would stimulate a 6 page debate. Debate is good for the soul.

I have read with much interest all of the replies submitted and would like to thank all posters who provided both advice AND criticism of my flying skills. I have learned a lot from this post and am determined to iron out this flaw that has been exposed in my flying technique with an instructor before I fly solo again.

Thanks again all posters for taking the time to enter this debate.

Regards

Smith

Beagle

Maybe the clean departure stall is more applicable in the USA, I don\'t think there are any airfields in the UK above 7,000msl (or Florida, 17ft is highest point amsl in FL) which could attain an OAT of 25-30oC.

Sorry it was just an added comment I noted after reading all the posts again but I do appreciate what you are saying.

O.K. Troops here are my comments.

First lets get this out of the way.

Quote:

.........................................

" it would be good to understand the FAA and CAA views and evaluate the differences in logic. "

..................................................

Before we can intelligently reply to the issues that Smith outlined in the first post here we must understand that connecting FAA / CAA and logic can be probmematic if we try and connect the dots using that avenue to search for an answer. :E

I see nothing wrong with the instructor expecting Smith to demonstrate correct control inputs into the recovery from the situation that the airplane had progerssed to.

He stated clearly that he was over controlling with rudder in a critical attitude at full power.

Further training in the handling of the airplane in question was not an unreasonable expectation on the part of the instructor that was evaluating his skills level to safely fly the Cessna 152.

I do not really think that something as acedemic as this issue required six pages of hand wringing and navel gazing to give him an answer to his question.

There that is about as simple as I can put it troops. :ok:

Your friend .....

Chuck E.

Not wishing to appear dim but what is a 'whip stall' ?

Chuck

Thanks for your thoughts. I can see where you are coming from.

Maybe the difference of opinion between the two instructors at the FTO that smith reported was a result of trying to connect these dots and it then makes me wonder about the wisdom of mixing FAA and CAA training regimes (since there seem to be some differences in approach, but both systems produce good outcomes - a bit like different airlines SOPs), but that's probably way too far off subject ;)

LNS

I believe that "whip" stall is another name for a stall turn, but no doubt someone will correct me if I'm wrong.

It appears to consist of an aggressive pitch to the vertical, followed by a short tailslide and 'hammerhead'. Anyone who has been taught aerobatics will probably have experienced such an unpleasant manoeuvre during 'recoveries from the vertical'.....

After Docklands Doris' exit from the Royal Marines this very day in 1987, in the spirit of the 'Prince of Wales' left, right, pushover fleur-de-Lys vertical manoeuve, this vertical manoeuvre was nicknamed the 'Prince Edward' - pull up into the vertical, then give up!

have not read the full thread, but I have to say this.

power on stalls are very useful if you get the chance to experience them, often with surprising results that most of us would not realise happened until we performed them.

I did power on stalls in my PPL, and I now know why they are taught.

you **will** find them useful .........honest, especially if you do aeros, and what the hell, it does give you a better feel for the aircraft.

cheers

7gcbc

Simply another name for a stall turn / hammerhead.

tKF

Normally where the aircraft is stalled, then forced hard nose-down with the pitch control simultaneously with the pitch break, giving a very high nose-down pitch rate which can potentially damage the aircraft.

G

Yep, I'd buy into that.

BEagle seems to have it right in my opinion though the use of the term "hammerhead" might confuse those from across the ocean where it describes what we in the UK know as a stall turn.
My own definition of a "whip stall" is one where the aircraft is placed in an extreme climbing attitude, say over 70 degrees nose up, and at the stall the aircraft very smartly swops ends in pitch into a vertical dive. If the climb attitude is just below 90 degrees then any tailslide will pitch canopy up and if just over 90 degrees then any tailslide will pitch canopy down. Such a manouever certainly falls into the aerobatic category and if carelessly executed in terms of a very firm grip on all controls can certainly result in structural damage.
Cheers,
Trapper 69

Yes indeed, Barry. Something we taught our RAF university air squadron students during early aeros lessons. But you couldn't do very many of these 'recoveries from the vertical' in one lesson before it would all go quiet as young Bloggs turned a delicate shade of pale green!

NOT a manouevre I would wish to practise in a traditional spamcan!

Hi Beagle,

You said:

This is what I used to do instinctively until the CFI who was checking me out for my Flight Test told me to pitch forward until the speed had increased significantly over the stall (say to Vx) before recovering from the descent.

In trying to figure out why his approach was better I guessed that just making the stall warning go away might result in wallowing along on the back of the drag curve.

Do you think I was right after all?

Not having been there, it's difficult to say. But if it's as you describe and the brief was to recognise and recover from the stall with minimum height loss, then yes, the CFI's exaggerated descent was wrong. Accelerating in a descent to Vx seems a self-defeating thing to do!

Wow, go away for a week and come back to ten pages of arguing around the point.

I still don't think that there is any real CAA Vs. FAA argument to have here. At the end of the day, you have to prove your competance to the person checking you out, it doesn't matter whether they're American or Martian.

My personal opinion is that everybody should experience spinning at some point in their training. An out of balance full power stall, should see to that nicely!

Stall recovery....... Keep the Bl**dy ball in the middle please!

Is there not a requirement under JAR to teach stall in the take-off configuration which, the last time I did it in a trainer was with no flap and the power at full throttle. I suppose it depends on how one describes take-off configuration but I will wait for the next Cessna to take off with the power at idle or even 1700rpm on a calm day.

As for the stall turn- a vertical climb to the maximum vertical extent at whic point the aircraft is rotated about the normal axis using rudder to enter a vertical descent and

whip stall - a stall entered from a deceleration that is well above the normal 1kt per second deceleration resulting in a positive often abrupt lowering of the nose at the point of stall.

Where we come from the standard stall recovery is always into the climb.

To judge how soon the pull out of the descent during the recovery the answer is as follows;

1. Aircraft reaches climb attitude but speed is above climb speed - pull out to late/ at too high a speed.

2. Aircraft reaches climb attitude but speed is still below climb speed - pull out too soon / at too low a speed

3. Aircraft reaches climb attitude at the moment speed reaches climb speed - correct.

Regards,

DFC

Hammerheads
 

Hammerheads are fun and relatively straightforward (timing) , but occasionally have the ability to scare the be-jazus out of you. The mechanics (physics) are fascinating.

and the buffet depending on the a/c is often a very clear and obvious cue to step on the rudder and use as much neutral pitch opposite stick (left hammer, right stick - counter the downgoing wing loss of lift (outside wing faster = more lift), right rudder, power off as she passes the horizon, approaches the near vertical downline)

if you get it wrong (and I have) you'll end up on your back due to both the torque (pronounced effect at low speeds) and the difference in lift on the down going wing and "top" wing (i.e the one on the outside) will put you embarassingly on your back :D DOOH!

its fun tho!

there is also a possibility of her sending you a very clear message by literally spitting you into a spin, usually in the direction of your hammerhead if you don't cut the power - now that wakes you up!!

The pitts is a case in point, very skittish so you need to be spot on with the rudder and stick - often going from a left hand spin into a right hand sans petit temps if you go to hard on the opposite rudder

SAS

So we come full circle! Thus my opinion is that it is not sensible to undertake a manouevre that mightcause a spin, in an aircraft that is not certified for spinning and that is loaded at the back limit of it's cofg and only a few pounds under gross.

Why take the risk, when you can walk down the flight line and choose a Cessna (or even a PA38) that is cleared for spinning and has a recovery technique in its POH.

But there you go. Its obviously sensible to practice stalls regularly (apart from whip stalls, having heard the description) in a suitable spamcan and also slow flying as Slim Slag described.

Ah, but in reality you are (probably) more likely to stall when when close to MAUW.

I agree that practising this when close to the limits is not the best idea I've ever heard, but if you were uncomfortable about doing these manoeuvers in that machine why not just change a/c?

Being certified for spinning is one thing, but just because the FAA or CAA don't let you spin it on purpose, doesn't mean that the a/c won't spin on its own accord if handled poorly. So if you are to fly that type, then you should learn ALL its foibles and peculiarites such as what it's like in the incipient stage.

If flown correctly, then a full power stall shouldn't lead to a spin, therefore no problem.........

SaS

I'm happy to let you have the final word on this.

Hey,

Having just read through all seven pages I'm still a bit confused about the terminology and the fuss about these power-on stalls. Where I trained for my CPL we often did power-on stalls from a climbing turn. You would have to pitch up rather sharply and be sure to keep the ball centered. The stall was eventually entered at a fairly steep attitude and here you could either start a normal recovery or, if the yoke was held back and a slight bank angle kept on, the outside wing would eventually drop in a somewhat unsettling manner. This was something we practiced from a very early stage and we were also encouraged to do it on our own.

Are we talking about the same thing here? I did my first one after about seven hours of total time and never thought twice about doing it solo after I got used to the scary wing drop. Sure there was a risk of spinning but I just kept the ball centered and never thought about that either. In fact I've never looked at this as more special than steep turns or something - until now. Is this not normally trained and would it be regarded as an extreme or abnormal manuever?

And I now offer a report of a strikingly similar incident, which fortunately involved only the loss of the Mooney rather than the occupant's lives.

I don't think this settles the case debated in this thread either way, but it does demonstrate the need for proficiency at least in managing the incipient stall with power on, particularly in more powerful light aircraft than your average trainer.

I'm a bit late to this thread, but the only fatal accident at my home airport (Palo Alto, CA) was a low-time pilot who got into a power-on stall/spin on climbout. So yes, it can happen.

I frightened the bejasus out of myself in a power-on stall while I was training, solo - my first ever rapid wing drop. I can't honestly say I like them, but they can happen. It's quite likely that the Cirrus that chute-landed near Fresno a few months back spun out of a power-on stall, although the Final Report isn't out yet. (He was very close to the ceiling for the type).

To open another can of worms... really every pilot should do spin and advanced stall training once they've got a few hours under their belt. (I agree with not having it be part of primary training but should be done once you feel completely comfortable with normal flying). That way nothing really frightens you. Of course it IS dangerous... to the wallet. Next thing you're flying acro for fun and having a heck of a time, but it isn't cheap :-(

While I'm at it, what exactly is an "incipient stall"? The warning horn? Buffet (doesn't happen much in Cessnas anyway)? First sign of the nose pitching down? "Recovering" from the warning horn isn't recovering at all. Really you should be able to fly the plane in a continuous stall, with the stick/yoke held back, keeping the wings level with rudder. (Some people call this a falling leaf, but there again others use it to mean something else).

n5296s (just back from trying, and almost succeeding, to land the Pitts!!)

BEagle,

That shade of green would be the same as I went when conducting my first stalling sessions in the UAS. My instructor, the Boss, became rather pi**ed off at my inept attempts in firstly actually recognising the stall and secondly doing something about it!! He then proceeded to demonstrate that it is possible to stall at any AoA - inverted, 90degress AoB etc!!

Quite an interesting and thoroughly useful lesson!!

Incipient is the light buffet.

You can't tell incipient from the attitude, as you can stall in a high nose attitude, a turn or relatively flat.
You can't tell from the airspeed. Low airspeed isn't always the sign of a stall as you can fly slowly and not stall, and you can stall at high speeds.
And you most certainly can't rely on the stall warner!

Other people may have different outlooks on what the incipient is!

In gliders where stalls and full spins are still taught as routine. An incipient spin is where one wing drops and you recover before the aircraft falls into a fully developed one (ie starting to rotate). I've always assumed it was the same in powered a/c. A pre-stall buffet is just that ... a pre-stall buffet, surely?

SS

Incicpient spin = undemanded roll

Incipient stall = light buffet

Oh yes ... Oops, I didn't read the question properly. I see now the question wasn't even about incipient spins :\

SS

I just love all the comments about people experiencing stalls when flying solo.

We teach slow flight, stalling and spin awareness so that primarily one can avoid the stall at all times and so that in the unlikely event that while avoiding stalls at all costs, one should accidently stall, one can recover with minimum height loss.

We do not teach spins and spin recovery because if one never stalls one will never spin.

Sounds very logical to me until the instructor then sends a student off solo with the actual intention of entering a full stall (does not matter if it is with or without power applied).

That act throws the whole rationalle out the window.

Why is there any need for a low hours inexperienced nervous student to practice something that is to be avoided at all costs?

All the stall training I do with students is done dual.........if they can do it dual or with an examminer then they do not have to "prove" anything by doing it solo..............and thus when they get a severe wing drop during a stall with full power applied, I am there to provide support and guidance if it is required!


Regards,

DFC

In the Camel........................no let us not get into that. I just wonder where some of the 'reasoned' arguments come from - as well as some definitions.

I can't get my mind round the apparent need NOT to teach spinning. It is true that some spam cans won't spin. The Jodel range are generally expected not to spin. But I have done it. Some aeroplanes drop a wing, when, of course, some recovery techniques shown here are dangerous. I mean you wouldn't lift the wing with aileron - would you? I have known many who have done so until I helped them understand why you should not do it and how easily it leads to a spin. But why didn't they know?

Straightforward stalling should be simple, and it usually is. But what about the one that catches the unwary out?

Recovery is the MOST important aspect of all stalls. If it goes wrong and you spin? What then? Who taught him/her to recover from it? What about the Chipmunk and its demand that the stick MUST be fully forward before initiating recovery from the subsequent dive, always assuming you performed the correct procedure in the first place, if not it will follow the many that have crashed through incorrect spin recovery technique. I also note that the topic is mainly about power on stalling, but that doesn't mean a new student won't experiment with stalling with it off.

I do of course recognise that an instructor will point to all the problems 'associated' with a possible spin, but my point is that it leaves the ACTUAL recovery to the solo unwary who have NOT been shown how. I would not take a bet on result that's for sure.

As you will note I am a strong advocate of teaching students to spin. I agree that you cannot do it in all aircraft so perhaps a bit of voluntary training on one that does would be more than helpful.

Camel - as one for whom a Pre-PPL exposure to full spin recovery has helped out of the cack once, I endorse your views (without getting too involved in the age old 'you shouldn't have got into that situation' route). I was also fairly fortunate in having had about 40 hrs of flying as a cadet on AEF, much of which was upside down in Chippies! This at least helped me to remain calm and think logically through recovery actions, rather than just a random thrashing of the controls.

Personally I think every pilot must experience spinning at some point and that the basic spin recovery for the type you are flying should be burnt into your memory.
My first CFI used to say" you only know the recovery well enough if I wake you at 2 in the morning shining a torch into your eyes shouting 'spin recovery' and you can trot it out exactly."

Spinning should never be taken lightly as an excercise which is why I wouldn't want it to be a mandatory part of the syllabus, but doing it voluntarily in a type that is capable and with an experienced Instructor is something I try to promote.

Hi guys,I haven't read the whole thread, but I must say I have always wondered about this: my theory is that it is typically not clearly explained to students WHY the stalls are being practised other than "here's what you have to do to pass your test"...

From some conversations overheard at the bar about "practicing stalls" when solo, post-PPL, I have the impression that many people see it as some sort of skill; whereas my interpretation is that you need to get used to recognising what it looks, feels and sounds like so you can take immediate action to recover, ergo it should normally be avoided!

On the other hand, I understand why spin-training would be a good idea and regret I haven't had any!!!

Just my two-penneth worth!

Andy :ok:

You could argue that there is more benefit in teaching students slow flight.....i.e. 50 kts, turns, climbs, descents etc.....than teaching spins.

It is important for a pilot to be able to recover from any stall and stall recovery is nearly always the same, but as for spin recovery, many aircraft are different, so what's the point in teaching spin recovery techniques? (They don't teach you to recover from a spin in a Citation, or Boeing).

Spin recovery in a Cirrus is to pull the chute. Even I could manage that without ever spinning a cirrus ;) Read the POH or the placard in front of you before you fly a different type.

EA

You make an interesting point.

I've certainly been through a couple of very interesting biennials in the states, where we investigated the low flight end of the envelope, in different configurations and attitudes and it was fascinating learning.

On the practical side one might reflect that many pilots pootling around SE UK at 2000 ft or so would have plenty of altitude to execute a stall recovery, but precious little to recovery from a spin. In the circuit, a stall recovery is certainly possible, a spin recovery unlikely (although I believe not unknown.)

So whilst I am certainly not anti spin training, I do believe that be familiar with slow flight on type and pre stall symptoms is very important.