Heavy Aircraft Stall Training

[Oldman731]

Where do you get that statistic?  

Oh sit down and be quiet, Puma, you can't even begin to understand these things.

- oldman

[Puma44]

Yeah, you're right, Oldman......pretty technical stuff.   

[hitech]

Restated for colmbo

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

HiTech

was a typo also.

To stall inverted , you are pulling negative AOA decreasing AOA would mean having less aoa, less aoa then -10 is - 11. So is the key to stall recover always decreasing AOA?

HiTech

[FLS]

Restated for colmbo
was a typo also.

To stall inverted , you are pulling negative AOA decreasing AOA would mean having less aoa, less aoa then -10 is - 11. So is the key to stall recover always decreasing AOA?

HiTech

Depends on your reference point.  -11 degrees is a greater angle than -10 degrees.

[pembquist]

I still don't understand. If the aoa is the angle between the mean chord line and the relative wind it's the absolute value of the angle not the sign that is significant.

[Valkyrie]

It's relative.

Inverted you would need to increase the aoa. B/c the separation in due to the large negative aoa getting your lift vector in the right direction. To correct that separation increasing aoa will correct the separation and inverted flight can continue with an air foil with the flow attached.

I have neve Rome aerobatics before, but that would be interesting as the Cm might not be in your favor, almost like an out of balance f-16 at test pilot school where they turned off the light computer and stalled it 600 lbs tail heavy.

Yes the absolute value is only importent if dealing with a symmetrical airfoil. Sign is important if the is as symmetrical.

[pembquist]

I don't understand, inverted or not, symmetrical or not you are reducing the angle between the direction of relative wind to get the flow reattached. Isn't it correct to say that -10 is a larger angle than +5?

[Valkyrie]

Correct.

[pembquist]

OK so I think my confusion is semantic and about nomenclature. If I was flying inverted pushing on the stick to climb and began to stall I would not say or conceptualize recovery to be "increase angle of attack" by letting the stick come back. I would say and conceptualize that I was lowering the angle of attack by letting the stick come back. So now I think I understand Hitech's question.

[hitech]

OK so I think my confusion is semantic and about nomenclature. If I was flying inverted pushing on the stick to climb and began to stall I would not say or conceptualize recovery to be "increase angle of attack" by letting the stick come back. I would say and conceptualize that I was lowering the angle of attack by letting the stick come back. So now I think I understand Hitech's question.

Yep you understand the question.

Also from experience, the RV has a nasty snap when you stall inverted. It's stall speed is about 30 knots higher flying inverted then right side up.

I also found that the first time you use your climb rate indicator while inverted, for some reason it messes with your head which way is which.

Also, no matter how hard you try to clean the plane before planned sustained inverted flight, there will always be a special piece of dirt in the correct position to drop into your nose.

HiTech

[earl1937]

Yep you understand the question.

Also from experience, the RV has a nasty snap when you stall inverted. It's stall speed is about 30 knots higher flying inverted then right side up.

I also found that the first time you use your climb rate indicator while inverted, for some reason it messes with your head which way is which.

Also, no matter how hard you try to clean the plane before planned sustained inverted flight, there will always be a special piece of dirt in the correct position to drop into your nose.

HiTech

Good point! Ever watch it while a student is doing an outside loop in a S2 Pitts? That will blow your mind!

[Citabria]

...Also, no matter how hard you try to clean the plane before planned sustained inverted flight, there will always be a special piece of dirt in the correct position to drop into your nose.

HiTech

I try to keep the dirt suspended in mid air or pinned to the floor if I am upside down at all after seeing how much dirt can get airborne in an SNJ texan.

[Citabria]

I will play devils advocate to the origional discussion in this thread that deals with basic stick and rudder skills or lack thereof.

how do these things keep happening?

Colgan captain does a stall pancakes kills everyone.

Airfrance copilots crash while captain takes a nap. Berlon had the stick held full back the entire time the aircraft was stalled and decending and the entire time kept saying "whats happening? I dont understand" and never mentioned to the rest of the crew his fatal actions with the controls.

situational awareness was completely lost by a fatigued and undertrained and/or underskilled crew with the usual result of death to all onboard. both planes could have recovered easily with max power and pushing the yoke forward but the controls were held full back until the crash was unavoidable.

the general conclusion of these accidents is the crews were inexperienced and deficient in their abilities to safely command an airliner under the worst conditions when at their weakest most fatigued and debilitated cognitive state. had they been fresh well rested they might have reacted more correctly but they did not and everybody died as usual.

humans will always find a way to screw up and because humans make and service the computers and components of aircraft they will screw up sooner or later as well so there really is no ironclad humanproof airplane because even if computers fly the aircraft from gate to gate those computers were made and maintained by humans and also have the chance to break down.

[Karnak]

China Airlines Flight 006 is another example, though the pilot did manage to recover the aircraft once he dropped below the clouds.  He didn't believe his ADIs because what they were telling him was so unbelievable compared to what he thought was happening that his first assumption was that they were broken.