Unusual attitudes
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A swept wing tends to stall outboard first unless it has clever design features to prevent it
(Aerodynamics for Naval Aviators, 1965, p.78)
A straight rectangular wing with no washout stalls inboard first
https://www.youtube.com/watch?v=ECTCVgiBHjA
(Aerodynamics for Naval Aviators, 1965, p.78)
A straight rectangular wing with no washout stalls inboard first
https://www.youtube.com/watch?v=ECTCVgiBHjA
Obviously this will vary dependant on wing design, but I have found it still to apply on some Civil Bis Jets. e.g Hawkers and Falcons.
I'd have to disagree with you here. Flying military swept wing jets (Gnat, Hunter, Lightning F4) the best turning performance was achieved by flying in the 'Light Buffet'. This is where the inboard wing is lightly stalled, but the outboard wing is still flying. Dogfighting manoeuvres and evasion were based on this principle.
Obviously this will vary dependant on wing design, but I have found it still to apply on some Civil Bis Jets. e.g Hawkers and Falcons.
Obviously this will vary dependant on wing design, but I have found it still to apply on some Civil Bis Jets. e.g Hawkers and Falcons.
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A basic swept wing tends to stall at the tip, but that's obviously undesirable so there's all sorts of tailoring tricks to avoid that, like washout, higher thickness outboard, stall fences, etc. (And some that didn't catch on, see Republic XF-91)
Where these mitigations are successful and a swept wing stalls root-first, is despite that it's swept, not because of it.
This was originally brought up as a difference between straight and swept wings (which makes it even more wrong with the implication that straight wings stall tip first) as a basis to defend the teaching of the absurd stall recovery technique of not reducing AOA, and using the ailerons while doing so.
Where these mitigations are successful and a swept wing stalls root-first, is despite that it's swept, not because of it.
This was originally brought up as a difference between straight and swept wings (which makes it even more wrong with the implication that straight wings stall tip first) as a basis to defend the teaching of the absurd stall recovery technique of not reducing AOA, and using the ailerons while doing so.
Last edited by Vessbot; 7th Dec 2020 at 15:29.
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[=-]]]The amount of misinformation on the Internet is staggering, and it is worrying that people actually come on here for actual flying advice.
Please don't quote out of context and without thoroughly reading the material. D P Davies' book doesn't say "STAY OFF THE RUDDER" as some sort of general rule for swept wing transport-category aircraft. The context is specifically recovering from "large bank angles in isolation" (aka not at a high enough angle of attack to have a wing drop on you or stall both wings, also not a combination of large bank angle + pitch upset) and for very high speed excursions where "in a type on which you are not sure of the rudder effectiveness in the way in which it rolls the aeroplane" (he is reffering to rudder reversal at high Mach).
Sure, you guys roll level on ailerons at the stall and let me know how it goes for you. Just please make sure there's no one on the plane with you.
While there is no intentional spin testing for these types, from flight test data and accident and incident data, we can gather that:
The Airbus A310 and B757 will happily spin.
The B717 will do at least one turn.
They can all recover, given enough altitude, but do you really want to put other people and yourself in that situation?
The Dash-8 also has a nasty wing drop, so does the PC-12 - and I'm sure that there are many other popular aircraft that have some pretty ugly power-on stall characteristics, although I don't currently have the data to back that up.
Long story short, if you're going to use ailerons at least have the decency to push forward and break the stall first. No you are not going into the ground because you've pushed forward on the stick. Pilots do it all the time on gusty approaches. Also, pushing the stick forward doesn't mean going 40 degrees nose down. You don't need that steep an angle at low altitude. It is simply a question of unloading the wings and cleaning up the airflow around them.
There has been an hysteria about use of the rudder ever since the horrible American Airlines A300 accident. By all means, use it judiciously - there is obviously the possibility of causing an even greater upset and/or breaking something, but if it needs to be used, it should be used! It's a main flight control and it's there for a reason, and not only for engine failures or tracking down the runway!
Please don't quote out of context and without thoroughly reading the material. D P Davies' book doesn't say "STAY OFF THE RUDDER" as some sort of general rule for swept wing transport-category aircraft. The context is specifically recovering from "large bank angles in isolation" (aka not at a high enough angle of attack to have a wing drop on you or stall both wings, also not a combination of large bank angle + pitch upset) and for very high speed excursions where "in a type on which you are not sure of the rudder effectiveness in the way in which it rolls the aeroplane" (he is reffering to rudder reversal at high Mach).
Sure, you guys roll level on ailerons at the stall and let me know how it goes for you. Just please make sure there's no one on the plane with you.
While there is no intentional spin testing for these types, from flight test data and accident and incident data, we can gather that:
The Airbus A310 and B757 will happily spin.
The B717 will do at least one turn.
They can all recover, given enough altitude, but do you really want to put other people and yourself in that situation?
The Dash-8 also has a nasty wing drop, so does the PC-12 - and I'm sure that there are many other popular aircraft that have some pretty ugly power-on stall characteristics, although I don't currently have the data to back that up.
Long story short, if you're going to use ailerons at least have the decency to push forward and break the stall first. No you are not going into the ground because you've pushed forward on the stick. Pilots do it all the time on gusty approaches. Also, pushing the stick forward doesn't mean going 40 degrees nose down. You don't need that steep an angle at low altitude. It is simply a question of unloading the wings and cleaning up the airflow around them.
There has been an hysteria about use of the rudder ever since the horrible American Airlines A300 accident. By all means, use it judiciously - there is obviously the possibility of causing an even greater upset and/or breaking something, but if it needs to be used, it should be used! It's a main flight control and it's there for a reason, and not only for engine failures or tracking down the runway!
Then you need to reread page 245 on Handling the Big Jets Where Davies discusses the recovery from gross upsets. Paragraph e.
If a gross upset is not an unusual position then I dont know what is.
On a lifetime of flying big jets the only time I have seen more than 30 degrees of bank was on VC 10 dutch rolling training when things got quite aerobatic ! Its a long time ago but MANUAL recovery to S &L was by use of AILERONS ONLY. No rudder input.
No hysteria about the A 300 fin loss, just sensible learning, reinforcing what was already known to most us, from a grossly mishandled jet.
Never spun the 757, a most delightful and benign aeroplane , ( except its “heavy” wing vortices.! )
If a gross upset is not an unusual position then I dont know what is.
On a lifetime of flying big jets the only time I have seen more than 30 degrees of bank was on VC 10 dutch rolling training when things got quite aerobatic ! Its a long time ago but MANUAL recovery to S &L was by use of AILERONS ONLY. No rudder input.
No hysteria about the A 300 fin loss, just sensible learning, reinforcing what was already known to most us, from a grossly mishandled jet.
Never spun the 757, a most delightful and benign aeroplane , ( except its “heavy” wing vortices.! )
Last edited by RetiredBA/BY; 8th Dec 2020 at 09:08.
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SPEED, high and increasing close the throttle, low and decreasing apply power.
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Then you need to reread page 245 on Handling the Big Jets Where Davies discusses the recovery from gross upsets. Paragraph e.
If a gross upset is not an unusual position then I dont know what is.
On a lifetime of flying big jets the only time I have seen more than 30 degrees of bank was on VC 10 dutch rolling training when things got quite aerobatic !
No hysteria about the A 300 fin loss, just sensible learning, reinforcing what was already known to most us, from a grossly mishandled jet.
Never spun the 757, a most delightful and benign aeroplane , ( except its “heavy” wing vortices.! )
If a gross upset is not an unusual position then I dont know what is.
On a lifetime of flying big jets the only time I have seen more than 30 degrees of bank was on VC 10 dutch rolling training when things got quite aerobatic !
No hysteria about the A 300 fin loss, just sensible learning, reinforcing what was already known to most us, from a grossly mishandled jet.
Never spun the 757, a most delightful and benign aeroplane , ( except its “heavy” wing vortices.! )
I have no quarrel with the rest of what you're saying.
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Comming from a glider, I nearly threw the instructor through the ceiling the first time I was trying the stall recovery.... Or I would if he wasn't wearing a seat belt.
Back to topic:
If you are flying with your hands off the throttle, the easiest is to push your nose until you can push the throttle.... If you have your hands on the throttle, do both simultaniously..... I really don't see a need to do one BEFORE the other.
I've never heard of a spin from vortices though, but it could be a problem in more powerfull aircraft than I'm used to.... Not sure if you'll spin though.... flip maybe?
There is one thing though, by increasing the throtthe, irrespective of pitch, you will automatically reduce the pitch from the increase in speed (unless you're pointing the nose very high), though the trimming will push you back again if trimmed to a low speed, so even the power first will present some result.
But generally, I've never found a stall something I have to "work on", just add power while pushing slightly brings you out of it pretty easily.
Back to topic:
I've never heard of a spin from vortices though, but it could be a problem in more powerfull aircraft than I'm used to.... Not sure if you'll spin though.... flip maybe?
There is one thing though, by increasing the throtthe, irrespective of pitch, you will automatically reduce the pitch from the increase in speed (unless you're pointing the nose very high), though the trimming will push you back again if trimmed to a low speed, so even the power first will present some result.
But generally, I've never found a stall something I have to "work on", just add power while pushing slightly brings you out of it pretty easily.
Last edited by jmmoric; 8th Dec 2020 at 12:27. Reason: Spin corrected to stall (see next post)
[QUOTE
Back to topic:
But generally, I've never found a spin something I have to "work on", just add power while pushing slightly brings you out of it pretty easily.[/QUOTE]
What utter nonsense, dangerous nonsense.
Back to topic:
But generally, I've never found a spin something I have to "work on", just add power while pushing slightly brings you out of it pretty easily.[/QUOTE]
What utter nonsense, dangerous nonsense.
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If you have your hands on the throttle, do both simultaniously..... I really don't see a need to do one BEFORE the other.
See my previous post. An aircraft with a large pitch-power couple at low speed (which you will be) can find itself in a world of hurt if you do as you suggest. What would be your first action if you run out of pitch authority with the nose way up in the air?
Last edited by Tay Cough; 8th Dec 2020 at 15:34.
There is one thing though, by increasing the throtthe, irrespective of pitch, you will automatically reduce the pitch from the increase in speed (unless you're pointing the nose very high), though the trimming will push you back again if trimmed to a low speed, so even the power first will present some result.
So if power is used to fly out of the stall then any pitch up will deepen the stall and therefore must be opposed by pitch down elevator. If you do not have any elevator pitch down force remaining then it will not be possible to stop an increase in the angle of attack. Thus the advice to reduce power (thrust) is to reduce the pitch up forces "if necessary".
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Very muddled language creeping in here, back to basics. Thrust and drag = pitch up, Lift and weight = pitch down. The lift weight couple dominates the thrust/ drag couple. The Horizontal stabiliser provides a down force providing a pitch up moment. The Trim tab is used to vary the down force of the horizontal stabiliser. Increase the thrust and the aircraft pitches up (thrust can also be gained from the speed by diving which will cause a pitch up also). So, increase the thrust and the nose pitches up aided by the increase in drag, then lift/weight opposes the pitch up but not completely. Any increase in speed will be a pitch up moment aided by drag. A initial large increase in pitch may be observed if thrust is added rapidly. As the forces stabilise the pitch up will settle downwards but not to the original attitude.
So if power is used to fly out of the stall then any pitch up will deepen the stall and therefore must be opposed by pitch down elevator. If you do not have any elevator pitch down force remaining then it will not be possible to stop an increase in the angle of attack. Thus the advice to reduce power (thrust) is to reduce the pitch up forces "if necessary".
So if power is used to fly out of the stall then any pitch up will deepen the stall and therefore must be opposed by pitch down elevator. If you do not have any elevator pitch down force remaining then it will not be possible to stop an increase in the angle of attack. Thus the advice to reduce power (thrust) is to reduce the pitch up forces "if necessary".
There have been many accidents and incidents where applying TOGA power with lots of nose-up trim caused a loss of control. Classic case: very slow on approach for x reasons, go-around on TOGA power, uncontrollable pitch-up. Well, uncontrollable without reducing power and/or getting on the trim fast.
The conversation seems to have significantly departed from the original intent. UPRT when taught in accordance with the EASA guidance materials, does not IMO conflict with what was traditionally taught in the “unusual attitudes recovery” exercise.
There will always be aircraft specific considerations which should be covered in the type training. This applies even in light aircraft. For example the Lake Amphibians have a high pylon mounted engine and a sudden application of high power can cause a strong pitch down instead of the pitch up pilots would expect with nose mounted engine
There will always be aircraft specific considerations which should be covered in the type training. This applies even in light aircraft. For example the Lake Amphibians have a high pylon mounted engine and a sudden application of high power can cause a strong pitch down instead of the pitch up pilots would expect with nose mounted engine
There will always be aircraft specific considerations which should be covered in the type training. This applies even in light aircraft. For example the Lake Amphibians have a high pylon mounted engine and a sudden application of high power can cause a strong pitch down instead of the pitch up pilots would expect with nose mounted engine.
The conversation seems to have significantly departed from the original intent. UPRT when taught in accordance with the EASA guidance materials, does not IMO conflict with what was traditionally taught in the “unusual attitudes recovery” exercise.
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The error has often been the pilot pushing the wrong button.
The training managers of airlines that I have spoken to did not see the value of throwing their pilots about in a Extra 300 as being useful.
You make an interesting point.
There can be little doubt that the basic principles of the stall may be demonstrated well using a light aircraft. It is not the case that UPRT training can be achieved in a light aircraft in my view. Stall recovery is mentioned only as an aside in the various UPRT manuals. The FAA documents and others so far quoted concern themselves very much with the interoperability of the complex automated systems and the pilot. That for me is where the work should be concentrated, and is, because the avoiding and the recovery from the stall by the pilot is not possible when the automation is preventing it or, indeed, is the cause. The error has often been the pilot pushing the wrong button. The training managers of airlines that I have spoken to did not see the value of throwing their pilots about in a Extra 300 as being useful.
There can be little doubt that the basic principles of the stall may be demonstrated well using a light aircraft. It is not the case that UPRT training can be achieved in a light aircraft in my view. Stall recovery is mentioned only as an aside in the various UPRT manuals. The FAA documents and others so far quoted concern themselves very much with the interoperability of the complex automated systems and the pilot. That for me is where the work should be concentrated, and is, because the avoiding and the recovery from the stall by the pilot is not possible when the automation is preventing it or, indeed, is the cause. The error has often been the pilot pushing the wrong button. The training managers of airlines that I have spoken to did not see the value of throwing their pilots about in a Extra 300 as being useful.
For example, GM1 FCL.745.A (g), nose low recovery, includes the enabling objectives:
(C) unloading to increase roll rate; (D) avoid ‘rolling-pull’; and (E) accept the priority of rolling to wings level first, before reducing power and before pulling.
If these are applicable to nose low or spiral dive recovery in a King Air, why would they not also be applicable in a DA 42?
(C) unloading to increase roll rate; (D) avoid ‘rolling-pull’; and (E) accept the priority of rolling to wings level first, before reducing power and before pulling.
If these are applicable to nose low or spiral dive recovery in a King Air, why would they not also be applicable in a DA 42?
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I'm assuming "Extra 300" was just meant as a stand-in for the concept of doing this in an actual light plane in general. If actually examining which is the best plane, I agree the Extra is not ideal, for its ability to get you out of anything with the instant flick of a wrist. Better would be something with a slow roll rate, so as to force the person to wait out some time, while the roll is still happening, still upside down and being forced to resist the temptation to pull during that whole time. Something with a yoke instead of stick, better yet for simulating the plane to be flown commercially. A 150 Aerobat would be ideal, except for having to climb for half an hour between every maneuver. A Decathlon (sans spades) is a fair compromise I think.