Angle of attack in a climbing turn

[photofly]

It's a well known factoid in aviation that in a climbing turn the angle of attack of the outside wing is higher than that of the inside wing. And for a descending turn the inside wing has a slightly higher angle of attack.

A prize goes to he or she who can provide a convincing explanation of this phenomenon.

[rob-air]

vector analysis and trigonometry

[Colonel Sanders]

Riemannian geometry and Jessica Simpson's diet?

[Cat Driver]

If I can gain a stroke changing hands will I win a prize?

[photofly]

Its because of inertial fame dragging caused by the interaction of the rotating earth, the rotating propellor and the rotation of the aircraft simultaneously about the yaw and pitch axes. A proper analysis of the Lense–Thirring effect can only really be conducted with an understanding not only of differential geometry but of covariant and contravariant derivatives defined on the tangent bundle of the appropriate manifold.

I can't help but think you're making it a bit too complicated.

[photofly]

If I can gain a stroke changing hands will I win a prize?

I'm having difficulty interpreting that in way that's compatible with the family nature of this website...

[T-roper]

Walk up a spiral staircase with a 2x8 as your "wings" and look at the higher AOA. Now walk down.

[JungianJugular]

If I can gain a stroke changing hands will I win a prize?

If you get the intake and exhaust stroke timing right, I'm sure you'd be setting yourself up for success. But be careful, too high a compression can cause detonation. Aim for a smooth controlled burn for longer lasting effects and satisfaction.

[Colonel Sanders]

you're making it a bit too complicated

If I told you I was drunk at the time when I posted that,
would it make more sense?

PS I don't think Jessica needed to go on a diet. All you
guys that like skinny chicks. Sheesh.

[photofly]

Colour me naive, but I had to ask my wife who Jessica Simpson is. I thought she was a cartoon character. (Apparently that's Jessica Rabbit.)

[JungianJugular]

you're making it a bit too complicated

If I told you I was drunk at the time when I posted that,
would it make more sense?

PS I don't think Jessica needed to go on a diet. All you
guys that like skinny chicks. Sheesh.

"Moses held out his staff and the Red sea was separated into two halves by God and the Israelites walked on dry ground and crossed the sea."

[Masters Off]

Jesus there has to be laws against how large those are.
What CAR prohibits such big knockers eh? Safety precaution of some kind?

What were we talking about again?

[Cat Driver]

I'm having difficulty interpreting that in way that's compatible with the family nature of this website...

I was going to delete it so as to not offend some of the purists here....but alas someone has copied it.

ssooo......what exactly is the importance of your original question?

Is it aimed at getting new pilots in a frame of mind to answer some of the mindboggling stuff T.C. puts in their exams?

[photofly]

what exactly is the importance of your original question?

Is it aimed at getting new pilots in a frame of mind to answer some of the mindboggling stuff T.C. puts in their exams?

There isn't an "aerodynamics for pilots" part of this forum, so I put it in flight training. I just think it's an interesting question. So far the only helpful answer requires me to attend a lumber yard and to construct a spiral staircase. I confess I was hoping for something quicker.

[Colonel Sanders]

"Right rudder, right rudder, right rudder!"

[burhead1]

Relative air flow. Also is it the same when flying a extra 300??

[Beefitarian]

All the turns I have been imagining were to the left but,

"Right rudder, right rudder, right rudder!"

That made my right foot twitch.

[Colonel Sanders]

Remember, eye candy is what makes our nation great

-- edit for family content

[Cat Driver]

O.K.

.....I will get into this angle of attack question with a question of my own.

If knowing the difference in angle of attack on each wing in a climbing turn or descending turn is really important do the new generation of computerized airplanes warn pilots when there is a difference in angle of attack between the two wings?

[DanWEC]

Boobies.

Now, I'll take a stab at the climbing turn AoA. Correct me if I'm wrong... the greater AoA actually switches sides during A)Entry, and B) The turn.

The ailerons change the AoA of the wing. Easiest to picture the entire wing, all the way to the leading edge as an aileron, since that's what they do anyways.
Lets say you're climbing wings level. You are a bit slow, and have a high AoA, close to stall speed.
You shove your stick to the left, and the airplane starts to bank to the left. The reason is you just increased the AoA (by the ailerons) of the right wing, giving more lift, causing it to rise, and causing the plane to begin to bank (which causes the turn).
If you're close to the stall AoA to begin with, then Whump, the right wing exceeds the critical aoa and it stalls.
Now, lets say that it was close, but that didn't quite happen, you reached your bank angle, checked your aileron input, and your happily banking and turning in your slow climb. Now your outside wing (right side) is moving faster than the inside wing, and subsequently generating more lift, so you actually check your aileron input more (ever so slightly to the right) to keep from overbanking. Now you are killing the lift on the outside wing more than on the inside due to the speed difference, to keep a steady bank attitude while in the turn. So what does that do to the AoA? Now you've reduced it on the outside wing and increased on the inside. If you are close to the critical AoA already, the inside wing will now be the one to pass that threshold first, and Whump, the left (inside) wing stalls.

*This doesn't take into effect adverse yaw however.

[gustind]

viewtopic.php?f=3&t=50654

[photofly]

@DanWEC - thank you, all true, but that's for level flight. I'm interested in how things change from level flight when you consider a climbing or descending turn.

@Gustind - thanks also. Very helpful.

[Ref Plus 10]

@DanWEC - thank you, all true, but that's for level flight. I'm interested in how things change from level flight when you consider a climbing or descending turn.

@Gustind - thanks also. Very helpful.

Assuming you are in a constant climb or descent, with no acceleration other than that caused by the turn, you wouldn't see a change from a turn in level flight, as all forces are in balance, hence no change in your rate of climb/descent.

[photofly]

Assuming you are in a constant climb or descent, with no acceleration other than that caused by the turn, you wouldn't see a change from a turn in level flight, as all forces are in balance, hence no change in your rate of climb/descent.

that's true averaged over the entire wing, of course, after the pilot has adjusted the ailerons against the over banking tendency. But the fixed part of the wing does have an AoA that varies span-wise in climbing and descending turns. Hence the need for more aileron against the bank in climbs and less in descents, when compared with level flight.

[DanWEC]

Ok, so you're talking about washout. The wing is designed with a higher AoA at the root so that it stalls first there, and still leaving the outer wing and ailerons to maintain effectiveness as you're at critical AoA.
Climbing and decending is irrelevant too, it's all about AoA.
So in a steady left turn with a constant bank, we've already established that the inside wing has a higher AoA.
Now if we place the entire plane at a high AoA, near critical, the highest AoA over the entire wingspan of the plane will be at the root on the inside (left) wing. That small section could be at or near stall, losing lift, causing the net lift of the inside wing to decrease, causing that wing to drop and bank to increase, necessitating the need for more opposite aileron.

But in reality, adverse yaw due to power changes for climbs and decents will have much more affect on turning characteristics in a single engine plane than this stuff.