Stall Recovery Technique
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Stall Recovery Technique
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Powering out of a stall is common on jets where on the Citation the technique is to hold the attitude while applying full thrust until the aircraft flies out.
I have never seen that technique taught in light piston aircraft?
Pace
I have never seen that technique taught in light piston aircraft?
Pace
In any case I still teach flying and I have always emphasized the importance of forward stick, followed by full power and rudder as required to prevent Yaw, as the correct response to a stall.
I am really happy that the large aircraft world has finally accepted that the only way out of a full stall is to reduce the angle of attack, and not to try and power out. Powering out may be possible in a high performance fighter, but is unlikely to be possible in the average airliner. It seems as if the non GA world is now experiencing a transformation in stall recovery techniques. Comments?
The citation has a stick shaker, and the recovery is full power and select flap on activation of the stick shaker , whilst maintaining attitude. So by definition is not a stall recovery but a low airspeed, high angle of attack recovery scenario
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I did a short course a few years ago on spinning and spin recovery from a fully developed one (in a Firefly)
One of the exercises we did prior to the spin recovery lesson was applying full power in a stall (in a C152) to see what happened. The result was somewhat alarming, as the moment I applied full power the starboard wing decided to fall out of the sky, followed by my stomach and the rest of the aircraft. Even then, all I had to do to kill the stall was to centralise the controls.
It showed me very graphically that the way to kill as stall was to reduce the angle of attack, and not to apply full power.
One of the exercises we did prior to the spin recovery lesson was applying full power in a stall (in a C152) to see what happened. The result was somewhat alarming, as the moment I applied full power the starboard wing decided to fall out of the sky, followed by my stomach and the rest of the aircraft. Even then, all I had to do to kill the stall was to centralise the controls.
It showed me very graphically that the way to kill as stall was to reduce the angle of attack, and not to apply full power.
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The ONLY way to unstall an aircraft is to reduce the angle of attack. I don't think anyone has said anything different to this, what has perhaps been debatable is how exactly we achieve this reduction in AoA. We should also be careful with terms, not to confuse AoA and pitch attitude. In a typical light aircraft training scenario, we reduce AoA by lowering the nose. However the AoA is that between the chord line of the aerofoil and the relative airflow, so you could also reduce AoA by changing the vector of the relative airflow, which is what is happening if you "power out of a stall".
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Accept that in the CAA doc
Note 1 Any manufacturers recommended stall recovery takes precedence over the advice by the CAA. So what i read into that is until the manufacturers change their recovery recommendations thats what we have to keep doing?
In the Citation thats not to pitch forward!
Pace
Note 1 Any manufacturers recommended stall recovery takes precedence over the advice by the CAA. So what i read into that is until the manufacturers change their recovery recommendations thats what we have to keep doing?
In the Citation thats not to pitch forward!
Pace
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Indeed, can't see the CAA overriding the manufacturer's recommendations/POH/flight manual, so I guess you'll just keep on doing what Cessna says for the Citation. Which is reduce AoA by moving the relative airflow vector (with lots of thrust) while holding a constant pitch attitude, is it not?
We seem to be talking about light aircraft a lot here, when really, if you read the safety notice carefully, the CAA concerns come from observations of SFI's and TRI's, which really excludes any relevance to SEP/MEP class aircraft. You would take it that they are really aiming at turbo-prop and jet aircraft operators, but for some reason have made it applicable to all GA pilots, all FE's & FI's and all FTO's & RF's.
We seem to be talking about light aircraft a lot here, when really, if you read the safety notice carefully, the CAA concerns come from observations of SFI's and TRI's, which really excludes any relevance to SEP/MEP class aircraft. You would take it that they are really aiming at turbo-prop and jet aircraft operators, but for some reason have made it applicable to all GA pilots, all FE's & FI's and all FTO's & RF's.
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Point taken and that whats puzzled me as I have never known an instructor teaching powering out of a stall in piston singles or twins.
In the Citation I have done stall recovery from clean to full flap/gear to flap app and in banked turns in the aircraft.
Once I reverted to a normal recovery pitching forward and the height loss was significantly higher with a scolding from the examiner.
Will have to e mail him for a response as to these recommendations.
Pace
Point taken and that whats puzzled me as I have never known an instructor teaching powering out of a stall in piston singles or twins.
In the Citation I have done stall recovery from clean to full flap/gear to flap app and in banked turns in the aircraft.
Once I reverted to a normal recovery pitching forward and the height loss was significantly higher with a scolding from the examiner.
Will have to e mail him for a response as to these recommendations.
Pace
Pace,what do you do if you are on one-engine ?
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In the Citation I have done stall recovery from clean to full flap/gear to flap app and in banked turns in the aircraft.
Have never actually tried it (I've always been taught to release the pressure on the control column while adding power) but I wouldn't have thought most light aircraft are even capable of recovering using power alone, I mean they might just pitch up more making it worse.
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I have never known an instructor teaching powering out of a stall in piston singles or twins
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Contact tower read this
I don't know much at Citations but I just assumed from this comment:
The citation has a stick shaker, and the recovery is full power and select flap on activation of the stick shaker , whilst maintaining attitude. So by definition is not a stall recovery but a low airspeed, high angle of attack recovery scenario
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The Citation 550 was certified without a stick shaker although I believe many had them fitted as optional extras and the 550 Bravo had them as standard.
Pace
The Citation 550 was certified without a stick shaker although I believe many had them fitted as optional extras and the 550 Bravo had them as standard.
Pace
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I understand that a stick shaker is a form of stall warning device. Therefore taking corrective action upon the shake (or horn/light in many other aircraft) is stall avoidance, not recovery. Avoidance is great, unless the purpose is to fully stall the aircraft (training).
A full stall is not caused by reducing power, so application of power is not the appropriate means of recovery - unless the manuafacturer says it is. If so, that procedure is a perversion of the correct technique, as it was not required to be demonstrated for certification.
Though not a design requirement, or the "normal" technique, a Lake Amphibian will generally power out of a stall, with no loss of altitude. Useful for a suddenly aborted water landing - perhaps an oddity.
Reduce AoA using pitch control, to prevent or recover a stall.
A full stall is not caused by reducing power, so application of power is not the appropriate means of recovery - unless the manuafacturer says it is. If so, that procedure is a perversion of the correct technique, as it was not required to be demonstrated for certification.
Though not a design requirement, or the "normal" technique, a Lake Amphibian will generally power out of a stall, with no loss of altitude. Useful for a suddenly aborted water landing - perhaps an oddity.
Reduce AoA using pitch control, to prevent or recover a stall.
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Standard Stall Recovery
Clearly, being a foreigner, I don't have the full picture. The Safety Note seems to be sending a mixed message. On the basis we are talking about relatively small aircraft, the confusion lies in where the recovery action is commenced. IE: Does the safety notice refer to a stall recovery from a fully developed stall, or to a "recovery during the approach to a stall?"
My interpretation is the latter.
Whilst the standard stall recovery will work in either case, what you do with your nose attitude is possibly different if you are only approaching the stall. Indeed, applying full power at the incipient stall stage should also reduce the angle of attack as a by-product of acceleration. With that in mind, the application of full power will also normally create a pitch up tendency (thus inducing a stall by increasing the AoA) unless the pitch up is prevented (at worst, maintaining the AoA at its pre-stalled state). I therefore interpret that this is what the SN is referring to?
Talking about approaching the stall as distinct to entering one, stick shakers are normally designed to precede the stall. Recovery on activation of the stick shaker would normally be an incipient stall recovery, or a recovery during the approach to a stall, rather than after the aircraft is stalled. One would have thought that whether the aircraft is big or little, it should be able to power out of an incipient stall recovery.
My interpretation is the latter.
Whilst the standard stall recovery will work in either case, what you do with your nose attitude is possibly different if you are only approaching the stall. Indeed, applying full power at the incipient stall stage should also reduce the angle of attack as a by-product of acceleration. With that in mind, the application of full power will also normally create a pitch up tendency (thus inducing a stall by increasing the AoA) unless the pitch up is prevented (at worst, maintaining the AoA at its pre-stalled state). I therefore interpret that this is what the SN is referring to?
Talking about approaching the stall as distinct to entering one, stick shakers are normally designed to precede the stall. Recovery on activation of the stick shaker would normally be an incipient stall recovery, or a recovery during the approach to a stall, rather than after the aircraft is stalled. One would have thought that whether the aircraft is big or little, it should be able to power out of an incipient stall recovery.
Nowhere in all this debate has anyone mentioned how far the control column should be moved - or when one should stop moving it.
As the AoA increases, an aircraft will exhibit various stall warnings - these mean 'stop what you're doing, or I'm going to stall'. Once the stall has been reached, the aircraft exhibits stall identification - this means 'see, told you I would!'.
To recover, the application of full power and control column centrally forward whilst maintaining balance is correct. But do not move the column further forward than the point at which the stall warning/ident ceases. Then level wings and recover from any descent - which, if prompt action has been taken at the incipient stage, should be almost zero.
At an early 'incipient' warning, the forward movement of the control column need be only so slight that it's barely noticeable. But maintaining the attitude and selecting full power to 'power out of the stall' (sic) is a fundamentally flawed technique.
The only time I didn't use full power for incipient stall recoveries was when conducting post-maintenance flight test on the VC10K. We had to check that the various warnings occurred at the computes speeds; once we reached the stick shaker 'climb power' alone was sufficient - and better than inducing engine surge by pushing all throttles fully forward. The pitch attitude change needed was very slight. The transport version of the VC10 was taken to the stick pusher, at which point the pilot had little ability to oppose the control column movement - as I once found out when an incorrectly rigged AoA probe triggered the stick pusher during a flapless approach....
As the AoA increases, an aircraft will exhibit various stall warnings - these mean 'stop what you're doing, or I'm going to stall'. Once the stall has been reached, the aircraft exhibits stall identification - this means 'see, told you I would!'.
To recover, the application of full power and control column centrally forward whilst maintaining balance is correct. But do not move the column further forward than the point at which the stall warning/ident ceases. Then level wings and recover from any descent - which, if prompt action has been taken at the incipient stage, should be almost zero.
At an early 'incipient' warning, the forward movement of the control column need be only so slight that it's barely noticeable. But maintaining the attitude and selecting full power to 'power out of the stall' (sic) is a fundamentally flawed technique.
The only time I didn't use full power for incipient stall recoveries was when conducting post-maintenance flight test on the VC10K. We had to check that the various warnings occurred at the computes speeds; once we reached the stick shaker 'climb power' alone was sufficient - and better than inducing engine surge by pushing all throttles fully forward. The pitch attitude change needed was very slight. The transport version of the VC10 was taken to the stick pusher, at which point the pilot had little ability to oppose the control column movement - as I once found out when an incorrectly rigged AoA probe triggered the stick pusher during a flapless approach....
