Heavy Aircraft Stall Training

[Karnak]

No it was Korean airlines 747. Capt attitude indicator failed and no one corrected him. He was a capt but low time on 747s. Prior to that he was an air force Col commanding f-16 squadrons. It was out of stanstead uk 50km north of london.

Ah.  Thanks for the correction.  The Koreans need to do something about that.

I recall looking at the crash of JAL 123 and the flight crew did a good job with what they had to work with, but there just wasn't enough for them given the terrain.

[hitech]

If you stall while flying inverted is it technique increasing or deceasing AOA what you go from -10 to -9 degrees of AOA?

One thing I am always amazed by is the fairly hi % of pilots who have never even done a roll in an aircraft. I was teaching a friend of my who has about 3000 hours of flight time including unusual attitude training.

I was teaching him hammer heads. I had talked him threw it before we left the ground, the up was no problem, I assisted a little on the kick and corner of the stick. But as soon as we were on the down line he was already pulling back on the stick, I was letting him make the mistake assuming he would feel what was happening, but he kept pulling to the point of the tail starting to slide out at which time i pushed forward and did the recovery. But what surprised me is that he never sensed the onset of the spin , nore did he sense the stall at very slow speeds even though we where headed straight down.

Another time when I was getting my check out in the RV from base to final I was a little nose hi, I simply increased the bank with a slight unload to let the nose settle. My instructor practically freaked thinking we would stall with a high bank angle not understanding what a "Knife in" Pitch down maneuver is.


HiTech

[colmbo]

If you stall while flying inverted is it technique increasing or deceasing AOA what you go from -10 to -9 degrees of AOA?

Say again, over.

[pembquist]

If you stall while flying inverted is it technique increasing or deceasing AOA what you go from -10 to -9 degrees of AOA

Hey Chief, what?

[earl1937]

If you stall while flying inverted is it technique increasing or deceasing AOA what you go from -10 to -9 degrees of AOA?

One thing I am always amazed by is the fairly hi % of pilots who have never even done a roll in an aircraft. I was teaching a friend of my who has about 3000 hours of flight time including unusual attitude training.

I was teaching him hammer heads. I had talked him threw it before we left the ground, the up was no problem, I assisted a little on the kick and corner of the stick. But as soon as we were on the down line he was already pulling back on the stick, I was letting him make the mistake assuming he would feel what was happening, but he kept pulling to the point of the tail starting to slide out at which time i pushed forward and did the recovery. But what surprised me is that he never sensed the onset of the spin , nore did he sense the stall at very slow speeds even though we where headed straight down.

Another time when I was getting my check out in the RV from base to final I was a little nose hi, I simply increased the bank with a slight unload to let the nose settle. My instructor practically freaked thinking we would stall with a high bank angle not understanding what a "Knife in" Pitch down maneuver is.


HiTech

If you stall while flying inverted:  It no longer matters, your wing is through flying and you really don't have any control until the wing recovers flying speed!

[Puma44]

   Say what?

[Valkyrie]

The problem with pilots is the understanding of critical angle of attack. To people everything is a relation to what they know, people relate everything back to the horizon. What pilots need to talk about is relative wind, angle of attack, and flight path. All are very different animals. And in talking stall recovery it should be in terms of decreasing angle of attack.

Angle of attack as related to relative wind as related to flight path.

Many pilots see it as angle of attack as related flight path, without the understanding of relative wind. My jeppeson book didn't talk about relative wind, only angle of attack and the critical angle of attack. Took my aerodynamics one book to get the relative wing concept.

Inveted or upright you have to understand  relative wind and the angle of attack as a function of relative wind. Having the aopa at a negative angle could work inverted providing the lift in the aero foil, much like and extra 300 with a near symetirical aero foil.

HiTech I think that is where your friend is missing a concept.

If you stall while flying inverted:  It no longer matters, your wing is through flying and you really don't have any control until the wing recovers flying speed!

Earl you too are missing the point it's about how the critical angle of attack is defined, it's got nothing to do with speed. But the angle between relative wind, and angle of attack. Speed just works on the relative wind. You need to work all those variables to get the desired flight path.

[Oldman731]

The problem with pilots is the understanding of critical angle of attack. To people everything is a relation to what they know, people relate everything back to the horizon. What pilots need to talk about is relative wind, angle of attack, and flight path. All are very different animals. And in talking stall recovery it should be in terms of decreasing angle of attack.

Angle of attack as related to relative wind as related to flight path.

Many pilots see it as angle of attack as related flight path, without the understanding of relative wind. My jeppeson book didn't talk about relative wind, only angle of attack and the critical angle of attack. Took my aerodynamics one book to get the relative wing concept.

Inveted or upright you have to understand  relative wind and the angle of attack as a function of relative wind. Having the aopa at a negative angle could work inverted providing the lift in the aero foil, much like and extra 300 with a near symetirical aero foil.

HiTech I think that is where your friend is missing a concept.
Earl you too are missing the point it's about how the critical angle of attack is defined, it's got nothing to do with speed. But the angle between relative wind, and angle of attack.

Well thank goodness that all of this has been made clear to me now.

- oldman

[Puma44]

Well thank goodness that all of this has been made clear to me now.

- oldman

Been wondering how long it would take you to figure it out, Oldman.  

[Puma44]

The problem with pilots is the understanding of critical angle of attack. To people everything is a relation to what they know, people relate everything back to the horizon. What pilots need to talk about is relative wind, angle of attack, and flight path. All are very different animals. And in talking stall recovery it should be in terms of decreasing angle of attack.

Angle of attack as related to relative wind as related to flight path.

Many pilots see it as angle of attack as related flight path, without the understanding of relative wind.

I'm guessing most "pilots" that are formally trained and licensed/rated understand the relationship between AOA and relative wind. 

Earl you too are missing the point it's about how the critical angle of attack is defined, it's got nothing to do with speed. But the angle between relative wind, and angle of attack. Speed just works on the relative wind. You need to work all those variables to get the desired flight path.

Just a guess, but, I think Earl probably has the concept down pretty well, considering his vast aviation experience....to include those as an instructor. 

How would you analyze the AOA, relative wind, airspeed, and stall potential here (just for the sake of discussion)?

[earl1937]

I'm guessing most "pilots" that are formally trained and licensed/rated understand the relationship between AOA and relative wind. 

Just a guess, but, I think Earl probably has the concept down pretty well, considering his vast aviation experience....to include those as an instructor. 

How would you analyze the AOA, relative wind, airspeed, and stall potential here (just for the sake of discussion)?

Well put sir! Sometimes there is a lot of difference in the "text book" and what really happens in the real thing! I understand exactly what Hi Tech is asking and I was just making the point that the "hip bone" is connected to the "thigh bone", so what difference does it make if you are right side up or not, if that darn wing quits flying, you are going to have to make a recovery post haste. In an inverted "flat" spin, you better know what you are doing, but most times, instinct takes over, backed up by a lot of piratical experience. If you are on the "gauges" is one thing, but VFR, you are going to have visual clues as to your reaction during recovery.

[Puma44]

Exactly, Earl!  The training and survival instinct take over and in the vast majority of cases, all is well and more valuable experience is gained.  Then, there are those times when buffoonery takes over and things don't work out quite so well.  

[Valkyrie]

9.5 out of 10 pilots today couldn't even begin to understand what is being discused here. If we could go back in time and ask the Cologan Air capt he couldn't explain it.

All pilots understand that a stall is the point at which the aero foil exceeds its given critical angle of attack and fails to produce lift.

All pilots will understand that to stop a stall you must break the stall first, where confusion sets in is how this relates to the flight path and speed.

Cl = L/qs

L is lift
Q is the dynamic pressure
S is the wing surface area
Cl is the lift coeficinet

So what I am getting at here is the speed does effect the stall but only as it relates to the relative wind, and needed lift produced.
A wing at a certain speed must produce a Cl to maintian the desired flight path.

[Valkyrie]

If the needed Cl exceeds the maximum Cl the wing can produce, the flight path will descend until enough energy Q is attained to come back into equilibrium. Assuming standard configuration. In effect the stall.

The Stall itself is the phenomenon of the the AOA exceeding the critical angle of attack and the flow becoming turbulent and not producing the needed Cl to lift the airplane.

Cl for a wing is a function of its angle of attack.

Cl * Q * S = L which works to produce the disired flight path along with Drag, Thrust, and weight.

Hence the accelerated stall, where its the flow over the wing that is turbulent and no longer producing lift.

So the stall is independent of the speed, but directly related to angle of attack, and the flow over the wing.

[Puma44]

9.5 out of 10 pilots today couldn't even begin to understand what is being discused here.

Where do you get that statistic?