Aileron or rudder during stall?
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Aileron or rudder during stall?
So I came up with this question while posting in another post and I wondered what everyone else's answers were to this. Only thing I ask is don't jump straight into the answer, give it a moments thought and weigh up the two sides.
So you hit a stall and a wing starts to drop, do you use option 1 or option 2 to correct the wing drop?
Option1 - Aileron
From what I remeber from my training back in 2010 you use rudder to correct and never aileron because you will cause the wing to hit a full stall and have a huge wing drop.
Option 2 - Rudder
You use the rudder's secondary effect to roll the aircraft back to level so you don't cause a bigger angle of attack on the recovering wing causing it to go into a deeper stall.
My issue with this is how do you get into a spin? Fully back on the control colum and full rudder at the stall no? So surly if you use rudder to correct a wing drop are you not jumping out of the pan and into the fire and putting yourself at risk of developing a rather dangerous situation of a fully developed spin?
So my thoughts are use a small amount of aileron as to not cause the wing to stall and if a wing drops then it's a damn easier to recover from than a spin?
You answers on a postcard please
So you hit a stall and a wing starts to drop, do you use option 1 or option 2 to correct the wing drop?
Option1 - Aileron
From what I remeber from my training back in 2010 you use rudder to correct and never aileron because you will cause the wing to hit a full stall and have a huge wing drop.
Option 2 - Rudder
You use the rudder's secondary effect to roll the aircraft back to level so you don't cause a bigger angle of attack on the recovering wing causing it to go into a deeper stall.
My issue with this is how do you get into a spin? Fully back on the control colum and full rudder at the stall no? So surly if you use rudder to correct a wing drop are you not jumping out of the pan and into the fire and putting yourself at risk of developing a rather dangerous situation of a fully developed spin?
So my thoughts are use a small amount of aileron as to not cause the wing to stall and if a wing drops then it's a damn easier to recover from than a spin?
You answers on a postcard please
Option 3 - Don't lift the wing up with anything. Use rudder to prevent it from dropping further, elevator to break the stall (still in a bank), and then normal coordinated controls to restore straight and level flight.
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No idea what to put as a title
Sorry yes I meant stop further wing drop rather than correct it back to level. My bad use of the Queens language!
But it's the use of the rudder all together than I have an issue with. Approach the stall, stop further wing drop, then go into Standard Stall Recovery
But it's the use of the rudder all together than I have an issue with. Approach the stall, stop further wing drop, then go into Standard Stall Recovery
First, you don't "hit" a stall; you and the plane's wing stalls when the AOA reaches the stall AOA. The plane enters a spin when at the stall AOA in uncoordinated flight. The elevators applied correctly and upon the first indication of a stall will reduce the AOA ; use rudder to maintain coordinated flight, perhaps a touch to stop or pick up the wing drop. BUT, reduce the the AOA promptly! And, remember flight controls are applied with pressures.
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The answer depends entirely upon the aircraft type, and the manufacturers guidance.
A straight wing behaves differently to a swept wing.
As an example, if you use rudder on an airbus, the fin will fall off and you will crash.
A straight wing behaves differently to a swept wing.
As an example, if you use rudder on an airbus, the fin will fall off and you will crash.
No. If you make rapid alternating full travel deflections of the rudder the fin might fall off. It also might fall off on a Boeing or any other type. Va does not give you any protection against rapid alternating full travel deflections in any transport category jet, it is not designed to, and never was.
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I am aware of that, i am being facetious.
Control input will vary with type and configuration.
That said, nose towards the earth will always help.
.
Control input will vary with type and configuration.
That said, nose towards the earth will always help.
.
Last edited by PURPLE PITOT; 19th Jul 2015 at 13:36.
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At the point of stall most aircraft are likely to drop one wing or the other, either due to the presence of yaw during the approach to the stall, or otherwise because no aircraft is built with perfect symmetry.
If yaw is not present and the angle of attack is allowed to increase, the wing drop is likely to be short lived with the other wing stalling very soon thereafter. At this point the aircraft becomes fully stalled, and the angle of bank will stabilize in the direction of the wing that stalled first (still assuming no yaw is present). In other words, and unless the angle of attack is increased, rotation (one wing stalled while the other generates lift) is not present or a primary concern.
Accordingly, as has been pointed out by others here, reducing the angle of attack of both wings simultaneously with elevator should be one's first concern, and then when the aircraft is un-stalled should one address leveling the wings. In this scenario using opposite aileron at the point of stall to level the wings, depending on the type, may make matters worse. Doing so generally increases the angle of attack on the wing that stalled first and reduces it on the wing that is still flying, and could lead to the development of a rotation. Unloading both wings with a pitch down is therefore a priority, but as those who are familiar with outside flick rolls will tell you the unloading with forward pitch should be done at a relatively gentle pace, and certainly not aggressively.
Off topic, but in jet types and when flying at high subsonic mach numbers, the angle of attack at which the wing stalls is substantially less than the angle at which the wing would stall at lower speeds/levels. Accordingly those flying older types without air data logic that correct for this anomaly, should be careful when operating close to ceiling limitations. Old style AoA indicators can mislead by as much as 30% when passing M0.75, and fool one into believing that they have a bigger stall margin than really exists.
If yaw is not present and the angle of attack is allowed to increase, the wing drop is likely to be short lived with the other wing stalling very soon thereafter. At this point the aircraft becomes fully stalled, and the angle of bank will stabilize in the direction of the wing that stalled first (still assuming no yaw is present). In other words, and unless the angle of attack is increased, rotation (one wing stalled while the other generates lift) is not present or a primary concern.
Accordingly, as has been pointed out by others here, reducing the angle of attack of both wings simultaneously with elevator should be one's first concern, and then when the aircraft is un-stalled should one address leveling the wings. In this scenario using opposite aileron at the point of stall to level the wings, depending on the type, may make matters worse. Doing so generally increases the angle of attack on the wing that stalled first and reduces it on the wing that is still flying, and could lead to the development of a rotation. Unloading both wings with a pitch down is therefore a priority, but as those who are familiar with outside flick rolls will tell you the unloading with forward pitch should be done at a relatively gentle pace, and certainly not aggressively.
Off topic, but in jet types and when flying at high subsonic mach numbers, the angle of attack at which the wing stalls is substantially less than the angle at which the wing would stall at lower speeds/levels. Accordingly those flying older types without air data logic that correct for this anomaly, should be careful when operating close to ceiling limitations. Old style AoA indicators can mislead by as much as 30% when passing M0.75, and fool one into believing that they have a bigger stall margin than really exists.
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Reduce AoA, and accept any "wing drop" prior to recovery, followed by CO-ORDINATED use of aileron/rudder to level the wings.
Most aircraft are designed with washout so that the wing stalls at the root first, and you should still be able to use aileron (and co-ordinated rudder) up to the stall with no ill effects, provided you aren't cack-handed and you have some idea what you're doing...
Most aircraft are designed with washout so that the wing stalls at the root first, and you should still be able to use aileron (and co-ordinated rudder) up to the stall with no ill effects, provided you aren't cack-handed and you have some idea what you're doing...
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Standard stall recovery as far as I am aware for all types has been standardised by a huge number of people far more intelligent than me as follows:
Disconnect Ap/AT as needed
Smoothly apply nose down pitch control to reduce angle of attack until the signs of the stall have ceased.
Roll in the shortest direction to wings level. Etc.
The first two actions hold true in every fixed wing aeroplane under normal flight conditions (ie not aerobatics). How you roll wings level will depend on type, don't use rudder in a 737 but on biz jets perhaps it is appropriate.
The sooner the industry wakes up to the fact that, a wing drop is a sing of the stall and that applying nose down pitch control is the first and most important action, the better.
Disconnect Ap/AT as needed
Smoothly apply nose down pitch control to reduce angle of attack until the signs of the stall have ceased.
Roll in the shortest direction to wings level. Etc.
The first two actions hold true in every fixed wing aeroplane under normal flight conditions (ie not aerobatics). How you roll wings level will depend on type, don't use rudder in a 737 but on biz jets perhaps it is appropriate.
The sooner the industry wakes up to the fact that, a wing drop is a sing of the stall and that applying nose down pitch control is the first and most important action, the better.
