Stall in a turn

[raytoews]

I have been having a spirited conversation with a couple of friends about stalls during a turn.
I have seen it in other articles that say the upper wing stalls first.
It is not logical to me.
I am assuming a stabilised turn, no aileron input and co-ordinated rudder.
There should be no reason for the upper wing to stall ahead of the lower.
Apparently common wisdom is the upper wing will stall in a climbing turn and the lower wing in a descending turn, although how you would stall in a descending turn I don't understand. Most general aviation aircraft are not capable of a pitch up.
I read an article about the staircase effect and it didn't seem conclusive.
Is this another one of those arguments,,,,like the up wind down wind turn nobody seems able to prove or disprove.
I don't have an aircraft I care to spin so am reluctant to go out and try it.


Is this splitting hairs?

Someone set me straight on this one.

Please.

[FlyingRon]

I agree with you. All that matters is ANGLE OF ATTACK not whether the aircraft is turning or climbing or which wing is "higher."
Now the wing on the outside of the turn is going to produce slightly more LIFT because it's going a little faster, but in coordinated flight (even in a turn) the AOA should be the same. Even that lift change is going to be negligible.

[Bill Berson]

The upper wing should stall first if you are holding the wing up with aileron. Because that barn door aileron changes the stall angle of attack to less than normal. So a wing normally stalls at say 15° neutral and say 12° with the aileron deployed down.
Many modern airplanes have this tamed by design. But old designs are still sold under old rules.

[DRGT]

When is a stabilized coordinated turn, lift is the same on both wings. Assuming the horizontal lift component is exactly equal to CF (virtually impossible assumption, but that is the definition of coordinated flight), both wings will stall at the same time.

[Bill Berson]

Lift is the same, but each wing can have a different aileron configuration to make that equal lift. Different configurations stall at different angles. Then torque, prop effects and everything else, it's a stretch to make broad one size fits all statements.
Thats why the topic is so involved and pilots keep killing themselves.

Post one said assuming no aileron input. But usually there is aileron input because the outer wing is moving faster. Aileron input can trigger the stall or prevent stall, just depends.

[DRGT]

Lift is the same, but each wing can have a different aileron configuration to make that equal lift. Different configurations stall at different angles. Then torque, prop effects and everything else, it's a stretch to make broad one size fits all statements.
Thats why the topic is so involved and pilots keep killing themselves.

Post one said assuming no aileron input. But usually there is aileron input because the outer wing is moving faster. Aileron input can trigger the stall or prevent stall, just depends.

Believe it or not, I agree in general with what you are saying, but the variables you rightly mention are negated by the OP's original assumptions. I also agree in those assumptions can only hold true in an academic discussion. Torque, prop effects, and control configurations, etc all have an effect in the real world.

I also agree that many pilots have insufficient knowledge in this area. Note my thread on LOC - spins. The FAA and AOPA and many other "experts" publish so a lot of false/misleading information. Primary flight instructors rarely teach anything beyond what they have read in a book or have been told. That is, they lack the experience to sense what is happening with the airplane (slip, skid, high angle of attack, etc.) and therefore lack the capability to pass on needed skills to students. I submit the lack of these fundamental knowledge areas and skills is the reason why pilots continue to kill themselves.

[raytoews]

Aileron should not be a factor in a stabilized turn. When banking the airplane I teach ,look, kick and turn, then neutralize, the airplane should continue at this bank angle (turbulence not withstanding) until you reverse the bank angle.

[Bob Dingley]

Somewhat off topic. A late friend instructed in B-24 and B-29's in the early 40's (until he was shipped to Tinian). He told me that part of the B-29 check out included stalls in a 60 degree bank. Of course, the complete crew was aboard.

[Floatsflyer]

Somewhat off topic. A late friend instructed in B-24 and B-29's in the early 40's (until he was shipped to Tinian). He told me that part of the B-29 check out included stalls in a 60 degree bank. Of course, the complete crew was aboard.

Practicing for steep turn to the left after simulating atomic bomb drop???

[Ron Blum]

Aileron should not be a factor in a stabilized turn. When banking the airplane I teach ,look, kick and turn, then neutralize, the airplane should continue at this bank angle (turbulence not withstanding) until you reverse the bank angle.

Unless one is flying an airplane with neutral or negative lateral stability, there will be a little down aileron on the up wing (and up aileron on the down wing). This may be masked by aileron system friction. We're not talking large amounts like 2-3 degrees, but there will be some. All certificated airplanes must have positive lateral stability.