Stalling
Why do it if it's not fun?
Joined: Jul 2001
Posts: 4,782
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From: Bournemouth
I know that at my school, the 2 hours stall-spin awareness is often severely curtailed
To the best of my knowledge, there is no requirement for any minimum amount of stall-spin awareness, and there hasn't been since the introduction of JAR. There are a number of different stalling scenarios to be covered, the aim being for the student to understand the symptoms of the approaching stall and the fully developed stall, and to be able to recover with minimum height loss. Once a student can perform these excercises satisfactorilly (and by that I mean that the student has demonstrated sufficient knowledge of the stall and the recovery of the stall to be able to carry out the exercises), move on to circuits. For some students, this will take less than an hour. For others it will take several hours.
FFF
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Joined: Jul 2003
Posts: 1,092
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From: uk
Question is why do we teach stall recognition and recovery.
When is an aircraft going to stall.
Probably not at 4000 feet on a bright sunny day.
When an aircraft stalls and the wing drops eg C152/PA38 the first thing a pilot does is apply opposite aileron, worsening the situation. And is unlikely to be power off.
It is an instinctive reaction to aircraft roll.
We all know it probably takes an hour of stall practise to teach the student not to use aileron, which quickly gets forgotten.
And i would imagine that any instructor on a windy day climb out experiencing severe wing drop would probably also use aileron to recover combined with rudder.
When is an aircraft going to stall.
Probably not at 4000 feet on a bright sunny day.
When an aircraft stalls and the wing drops eg C152/PA38 the first thing a pilot does is apply opposite aileron, worsening the situation. And is unlikely to be power off.
It is an instinctive reaction to aircraft roll.
We all know it probably takes an hour of stall practise to teach the student not to use aileron, which quickly gets forgotten.
And i would imagine that any instructor on a windy day climb out experiencing severe wing drop would probably also use aileron to recover combined with rudder.
Registered User **
Joined: Jan 2004
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From: Sydney
exactly right, you should stall the aircraft in as many possible legal flight configurations as you can manage, climbing full power, climbing turning full power , descending flaps, tighten up turns and so forth.
This malarky about straight ahead summers day stalling is leading students up the primrose path.
by the way Beagle, I have rolled a Cessna 152 years ago in a high AOA, slow speed , with flap and fullpower , and I can tell rudder had absolutely no effect round she went and we were along for the ride.......
and I pickup the downgoing wing all the time when I do aeros, and I do it with tap tap rudder, and whatever stick is rwq'd
This malarky about straight ahead summers day stalling is leading students up the primrose path.
by the way Beagle, I have rolled a Cessna 152 years ago in a high AOA, slow speed , with flap and fullpower , and I can tell rudder had absolutely no effect round she went and we were along for the ride.......
and I pickup the downgoing wing all the time when I do aeros, and I do it with tap tap rudder, and whatever stick is rwq'd
Fleet Manager
Joined: Apr 2001
Aviation Qualifications: ATPL
Posts: 7,447
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From: various places .....
Another consideration which I don't think anyone has highlighted relates to the certification requirements .. ie what is demonstrated and investigated during the OEM development and regulatory certification process.
This has varied over the years. One should have an idea of what the particular aircraft was subject to ... if one goes outside this .. then one might get an unpleasant surprise at some stage.
For instance, one popular light twin was certificated on the basis of only approaching to the indications of stall .. a very experienced test pilot instructor related the tale of one of his students who persevered with holding an example of the Type/Model into the stall ... and promptly ended up in an inverted spin.
What the OEM writes up in the handling notes, POH, etc., is worth giving due weight .....
This has varied over the years. One should have an idea of what the particular aircraft was subject to ... if one goes outside this .. then one might get an unpleasant surprise at some stage.
For instance, one popular light twin was certificated on the basis of only approaching to the indications of stall .. a very experienced test pilot instructor related the tale of one of his students who persevered with holding an example of the Type/Model into the stall ... and promptly ended up in an inverted spin.
What the OEM writes up in the handling notes, POH, etc., is worth giving due weight .....
Joined: Jan 2005
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From: LILE
Originally Posted by BEagle
TurboJ, I respectfully contend that the FIC instructor was an utter ar$e! If you do not control the a/c attitude and balance when applying full power, then stall recovery may well be delayed. Delaying application of full power will certainly increase the height loss during recovery.
For this reason I want that my students learn to:
1) reduce AOA and only after that
2) apply full power
Usually in the first recovery the student will lose a lot of altitude. But after 3 or 4 recoveries he/she take confidence with the sequence, full power is really close to nose down, and the altitude loss will decrease.
Ciao!!!
Rosanna
Joined: Jun 2001
Posts: 4,777
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From: Blighty
I find this thread very illuminating. People are talking about picking up wings with rudder and 112hp engines causing the aircraft to rotate around it's longitudinal axis with the controls having no effect and/or causing 'flat spins'. This all makes me believe that they have been taught incorrectly and are teaching incorrectly.
I'm talking about the CAA /JAR syllabus here and not the FAA or CASA one, which I have little experience of but I believe they are similar. I always thought that stalling exercise was a prevention exercise and to get the best out of it, recognition has to be taught first. Then recovery with minimum height loss in various configurations and attitudes. The key to this is with 'minimum height loss' and you can only achieve this with the application of power. This is how I was taught to teach the exercise and how I always did it myself.
1: Recognition - take some time on this, if the student can't recognize the warnings of the approaching stall or the stall itself there is no point in continuing.
2: Recovery - this can be achieved with reducing the angle of attack. You should elicit from the student the height loss, then point out the loss with use of power. (The last aircraft I was teaching on, the PA 28 typically lost 300' in a recovery without power, 100' with.)
This should take a minimum of a whole hour long lesson if it's going to be done properly with the average student. Then:
3: Recognition and recovery in other configurations/ attitudes (with flap, power, gear, air brakes, asymmetric, any attitude - even upside down if you like!) The key to this is the recovery with min height loss with the emphasis of saving you skin on the approach to landing stall. To achieve this effectively, you have to build up a scenario with a high workload and distractions. this should take more than one lesson.
The stall recovery is simplicity itself in it's execution (although you wouldn't believe it reading this thread!). You move the control column centrally forward until the buffet stops, simultaneously applying full power. You use the rudder TO PREVENT FURTHER YAW - and this only! When the wings are unstalled (i.e there is no buffet - and this is another reason you have to have to have the recognition squared away), you select a level attitude with aileron and elevator.
Some points on what has been said here.
Use of rudder: tramping the rudder around other than to prevent yaw is asking for trouble. The primary recognition points of an incipient spin are buffet with undemand yaw. If you demand some yaw intentionally by using more rudder than is required to prevent any yaw from the action of the stall or applying power, you are inviting the aircraft to spin.
Use of aileron: By increasing the angle of attack by lowering an aileron, you are inducing the wing to stall deeper. In my experience the only aircraft where aileron use with buffet was appropriate was a swept wing jet where the aerodynamics are very different.
Use of power: To reduce the height loss, you need power. The last aircraft I instructed on professionally stalled at about 80 knots and has a 1200hp engine. There was no problem controlling it at the point of stall with full power. The only aircraft to my knowledge which had a problem with this was the Bolton Paul Baliol with a 1600hp merlin engine. It was taken out of RAF service partly for this reason. If an aircraft cannot be controlled in this fashion it would not be certified. (This may not apply to some multi-engine types asymmetric if they are at or below their Vmca).
The only slightly dodgy stall characteristic I have ever experienced was the Tucano which rolls to about 120 degrees angle of bank at the stall in a final approach configuration stall in a left turn. Still, by following the recognized recovery technique, it is still possible to recover in about 400' safely. To get to this stage though, you have to ignore the warnings of the high nose attitude, the less effective controls, the low and decreasing airspeed, the audio warner, the stick shaker, the angle of attack gauge, the approach angle of attack indicator - and the buffet! This re-enforces the emphasis on recognition.
Roll on instructor standardization!
I'm talking about the CAA /JAR syllabus here and not the FAA or CASA one, which I have little experience of but I believe they are similar. I always thought that stalling exercise was a prevention exercise and to get the best out of it, recognition has to be taught first. Then recovery with minimum height loss in various configurations and attitudes. The key to this is with 'minimum height loss' and you can only achieve this with the application of power. This is how I was taught to teach the exercise and how I always did it myself.
1: Recognition - take some time on this, if the student can't recognize the warnings of the approaching stall or the stall itself there is no point in continuing.
2: Recovery - this can be achieved with reducing the angle of attack. You should elicit from the student the height loss, then point out the loss with use of power. (The last aircraft I was teaching on, the PA 28 typically lost 300' in a recovery without power, 100' with.)
This should take a minimum of a whole hour long lesson if it's going to be done properly with the average student. Then:
3: Recognition and recovery in other configurations/ attitudes (with flap, power, gear, air brakes, asymmetric, any attitude - even upside down if you like!) The key to this is the recovery with min height loss with the emphasis of saving you skin on the approach to landing stall. To achieve this effectively, you have to build up a scenario with a high workload and distractions. this should take more than one lesson.
The stall recovery is simplicity itself in it's execution (although you wouldn't believe it reading this thread!). You move the control column centrally forward until the buffet stops, simultaneously applying full power. You use the rudder TO PREVENT FURTHER YAW - and this only! When the wings are unstalled (i.e there is no buffet - and this is another reason you have to have to have the recognition squared away), you select a level attitude with aileron and elevator.
Some points on what has been said here.
Use of rudder: tramping the rudder around other than to prevent yaw is asking for trouble. The primary recognition points of an incipient spin are buffet with undemand yaw. If you demand some yaw intentionally by using more rudder than is required to prevent any yaw from the action of the stall or applying power, you are inviting the aircraft to spin.
Use of aileron: By increasing the angle of attack by lowering an aileron, you are inducing the wing to stall deeper. In my experience the only aircraft where aileron use with buffet was appropriate was a swept wing jet where the aerodynamics are very different.
Use of power: To reduce the height loss, you need power. The last aircraft I instructed on professionally stalled at about 80 knots and has a 1200hp engine. There was no problem controlling it at the point of stall with full power. The only aircraft to my knowledge which had a problem with this was the Bolton Paul Baliol with a 1600hp merlin engine. It was taken out of RAF service partly for this reason. If an aircraft cannot be controlled in this fashion it would not be certified. (This may not apply to some multi-engine types asymmetric if they are at or below their Vmca).
The only slightly dodgy stall characteristic I have ever experienced was the Tucano which rolls to about 120 degrees angle of bank at the stall in a final approach configuration stall in a left turn. Still, by following the recognized recovery technique, it is still possible to recover in about 400' safely. To get to this stage though, you have to ignore the warnings of the high nose attitude, the less effective controls, the low and decreasing airspeed, the audio warner, the stick shaker, the angle of attack gauge, the approach angle of attack indicator - and the buffet! This re-enforces the emphasis on recognition.
Roll on instructor standardization!
Last edited by Dan Winterland; 2nd April 2006 at 04:15.
Joined: Mar 2006
Posts: 26
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From: NZCH
I can't add anything to this post, except to offer thanks to Dan.
Dan's post has put my mind at rest that my training in recognising the 'incipient stall' in various configs and the recovery procedures wasn't at all incorrect afterall.
I was a bit concerned to read posts that suggested the rudder be applied for anything other than to prevent further yaw on applying power.
Dan's post has put my mind at rest that my training in recognising the 'incipient stall' in various configs and the recovery procedures wasn't at all incorrect afterall.
I was a bit concerned to read posts that suggested the rudder be applied for anything other than to prevent further yaw on applying power.
Thread Starter
Joined: Dec 2002
Posts: 285
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From: UK
Dan
Thanks for your post. I am very pleased to be 'singing from the same hymn sheet.'
However, I come back to my original point.
In a PA28,the stall itself includes an oscillatory pitching effect which the AAIB says is not included in ab initio flight training and should not be practised by UK flying instructors. However, students are required to be able to recover from a fully developed stall which includes this pitching effect.
Would it be right to say that as soon as this 'nodding effect' is reached, the student recovers or the fully developed stall should not be developed to include this oscillatory effect.
Regards......TJ
Thanks for your post. I am very pleased to be 'singing from the same hymn sheet.'
However, I come back to my original point.
Recognition - take some time on this, if the student can't recognize the warnings of the approaching stall or the stall itself there is no point in continuing.
Would it be right to say that as soon as this 'nodding effect' is reached, the student recovers or the fully developed stall should not be developed to include this oscillatory effect.
Regards......TJ
Joined: Nov 2005
Posts: 58
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From: Near Shobbers
Coming from a gliding instructing background, I can only concur the stall/spin recognition/avoidance/recovery is at least inconstantly, if not badly, taught.
BGA instructors are rigorously coached in stall spin recovery in all kinds of configurations and loadings at heights down to below 1000ft (some demo only).
There is a particularly nice one which involves stalling/spin entry in under and over ruddered turns and works really nicely in a C152. All my PPL students get to see it and have a go.
From my perspective the ‘spin avoidance only’ teaching is a bit of a cop out –possibly engendered by a lack of suitable available aircraft.
PF
BGA instructors are rigorously coached in stall spin recovery in all kinds of configurations and loadings at heights down to below 1000ft (some demo only).
There is a particularly nice one which involves stalling/spin entry in under and over ruddered turns and works really nicely in a C152. All my PPL students get to see it and have a go.
From my perspective the ‘spin avoidance only’ teaching is a bit of a cop out –possibly engendered by a lack of suitable available aircraft.
PF
Joined: Jun 2001
Posts: 4,777
Likes: 9
From: Blighty
From my experience, the oscillatory pitching effect of the PA28 at the stall is a result of the control column being held and maintained fully back and is a product of the high level of pitch stability enjoyed by that aircraft. If you get to that stage with a student, he/she is flying the aircraft to the limit of its angle of attack capabilities and is in a full deep stall. Remember that the aim of stall training is to recognise the stall at it's onset and recover with the minimum height loss. If you ever take the student to this stage, it should be once and for demonstration purposes only. The aim of this exercise is to recognise the warnings of an approaching stall and avoid them in the future. there should few reasons for the student to take a PA28 to the 'nodding' stage.
I'm glad that someone has bought up the subject of glider stall training. I first trained as a glider instructor and IMHO, glider stall training is superior to powered. Glider pilots are more likely to fly a wider range of types than power pilots and at speeds much closer to the stall. My experience comes from the Bocian (stall below 500' and it's goodbye) through the tailess Fauvel 28 (hoik the stick back and you can flick loop) to the Dart 17 with no washout (stall and you're guarenteed an incipient spin). Some gliders have truly horrible stall characteristics, but most are benign.
I'm glad that someone has bought up the subject of glider stall training. I first trained as a glider instructor and IMHO, glider stall training is superior to powered. Glider pilots are more likely to fly a wider range of types than power pilots and at speeds much closer to the stall. My experience comes from the Bocian (stall below 500' and it's goodbye) through the tailess Fauvel 28 (hoik the stick back and you can flick loop) to the Dart 17 with no washout (stall and you're guarenteed an incipient spin). Some gliders have truly horrible stall characteristics, but most are benign.
Joined: Dec 2005
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From: LKBU
Originally Posted by Dan Winterland
People are talking about ... 112hp engines causing the aircraft to rotate around it's longitudinal axis with the controls having no effect and/or causing 'flat spins'.
Joined: Jun 2001
Posts: 4,777
Likes: 9
From: Blighty
The Yak has a large heavy prop which will acts as a gryroscope. You don't want gyroscopice forces affecting the recovery. I think it has more to do with this rather than the airframe being spun around by the prop. In the Tucano, the incipient spin recovery was centralize the control column and close the throttle - for this reason. In the less powerful Chipmunk and Bulldog, it was just centralise the contol column.
Joined: Apr 2002
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From: In an office job
While we are on the subject of stall recovery. Just the other day during an
IR(ME) 170A, I carried out the standard stall recovery, ie Stick neutral/forward, Power Wings level etc. I was then corrected by the FI, to recover the Twin engine aircraft from the stall by basically powering out of the stall, no lowering of the nose to reduce AoA. As an FI myself this strongly goes against all of my principles and what I teach my PPL's. Thinking about this further after my 170A (which was signed off incidently), the implications of loss of power in one engine during a stall recovery carried out by power alone could be quite... well dangerous. Any views on ME stall recovery would be appriciated.
thanks
mint
IR(ME) 170A, I carried out the standard stall recovery, ie Stick neutral/forward, Power Wings level etc. I was then corrected by the FI, to recover the Twin engine aircraft from the stall by basically powering out of the stall, no lowering of the nose to reduce AoA. As an FI myself this strongly goes against all of my principles and what I teach my PPL's. Thinking about this further after my 170A (which was signed off incidently), the implications of loss of power in one engine during a stall recovery carried out by power alone could be quite... well dangerous. Any views on ME stall recovery would be appriciated.
thanks
mint
Joined: Feb 2005
Posts: 412
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From: essex
When a stall catches a student unawares we have hopefully instilled in the student an automatic reaction .....stick forwards and apply full power (simultaneously)
It is difficult to instill an instinctive reaction which has got many variables depending on circumstances hence why we have to boil it down to "pitch and power"
.
It is difficult to instill an instinctive reaction which has got many variables depending on circumstances hence why we have to boil it down to "pitch and power"
.
