Exactly! But I think the question (or one of them) was about the yaw created by aileron drag. As you pointed out, the author of the article had yaw and drag so screwed up that it left the reader confused. I was trying to address the adverse yaw that occurs on roll entry. Your picture of what is happening lift wise is perfect. The outboard tip going faster contributes to overbanking tendency (roll), but does not increase overall lift.
Jim Bair
From: James Ferris
Sent: Monday, March 19, 2012 8:10 PM
Subject: Re: Light-Sport Aircraft Yahoo group Re: Why does it TURN (not just slide sidewards) when you bank w/ no
Let us make it real simple, draw a little circle that represents the airplans flying away from us. Now draw a verticle and horizontal axis, and say the wing is producing lift and draw a line 6 inches long straight up and put a small aerrow at the top. Now consider a left bank of 45 degrees and rotate the lift vector of the wing 45 degrees now this vector can be resolved into a vertical componet and a horizontal component the length of each will be 6 inches (.707) or 4.24 inches. Now the horizontal componet is what causes the airplane to turn and the vertical componet of 4.25 is now the lift so the airplane cannot maintain altitude unless the we give it some up elevator to increase the angle of attack of the wing. The wing causes the airplane to turn and the rest of that stuff about the outboard wing tip fonig faster in not going to have much effect.
Subject: Re: Light-Sport Aircraft Yahoo group Re: Why does it TURN (not just slide sidewards) when you bank w/ no
I agree with what James says below with one exception. I disagree with #2 as well. That means #3 is the only correct statement in the entire article. #1 doesn't count, as it is simply a statement of the maneuver. The left aileron doesn't go up to create drag, it goes up for exactly the same reason the right one goes down, but in an opposite way. The right one goes down to create more lift, the left one goes up to destroy lift. Not to increase drag. The right aileron producing lift definitely creates more drag, and this is why the nose initially moves to the right if you neglect to step on the left rudder while rolling into the turn. This article is filled with errors and is poorly written. I suspect English as a second language may be part of the problem the author has. Read what Richard wrote. It's much more clear than the article you referenced, and it is correct. Just out of curiosity, where did you find that author? There are some good sources of info out there, this just isn't one of them. Try "See How it Flies". I think it's a pretty good aerodynamics primer and you don't need to be an engineer like James to read it.
Jim Bair
From: James Ferris
Sent: Monday, March 19, 2012 4:40 PM
Subject: Re: Light-Sport Aircraft Yahoo group Re: Why does it TURN (not just slide sidewards) when you bank w/ no
I am an Aeronautical Engineer and worked in Aircraft Performamce Stability and control for tne National Aeronautics and Space Association for Thirty years and worked on the F-111, F-15 ,F-16 , F-17, F-18, B-1. ,B70,Saturn V,Space Shuttle and many others and am also a Pilot. You have listed Seven Items 1,2 and 3 are correct, in item 4 replace left wing with right wing wing and it will be correct, and this is why you use rudder to compensate in the turn. Items 5 ,6 and 7are complete nonsense and the reason the aircraft turns is the Lift Vector that we had in level flight is divided into lift and a force to the left causing the aircraft to turn.
Subject: Light-Sport Aircraft Yahoo group Re: Why does it TURN (not just slide sidewards) when you bank w/ no
Hi Jim,
--- In mailto:Sport_Aircraft%40yahoogroups.com, you, "James Bair" <jimbair@...> wrote, In part:
> Your final paragraph about the lowered and raised ailerons is either totally incorrect or is simply worded in a way you didn't mean, because the drag you talk about is actually backwards.<
You were referring to my earlier saying this:
"I stand by my theory for now:
Somehow the bank must be creating more drag on the lower wing (or less on the raised wing) creating the turning force.
My guess is the raised aileron on the lower wing -- being in the
different airflow of the upper wing surface -- creates MORE drag on
the lower wing than the lowered aileron on the raised wing does. "
---
Well I may be wrong about the raised aileron on the lowered wing creating more drag on that wing, but if so I'm in some pretty good and credible company in believing that.
See the file "Yaw when banking aircraft.doc " that I just uploaded to our files area.
Or just go to --
http://www.decodedscience.com/side-effect-of-rolling-an-airplane-aircraft-yaw/7209 .
In part what it says there is --
"1. An aircraft initiates a roll to its left.
2. The left aileron (attached to the wing) goes up to produce drag.
3. The right aileron moves downward to produce more lift.
4. As a consequence of increased drag on the left wing, and increased lift on the right wing, the left wing rolls downward while the right wing rolls upward.
5. During this phase (with the left wing down and the right wing up), the right wing travels faster through the air and contributes more to the production of lift.
6. This increased lift acts diagonally and is divided into two components. The horizontal component of lift enables an airplane to roll in the desired direction.
7. The increased production of lift due to the right wing's relatively higher airspeed and its aileron in down position induces an aircraft yaw towards the left. "
Sounds like basically what I said.
The aeronautical credentials of the author (see the site) are good, and it makes sense to me.
So, I'm sticking with the "more drag on the lowered wing is applying the yaw (turning) force" for now.
Alex
--- In mailto:Sport_Aircraft%40yahoogroups.com, you, "James Bair" <jimbair@...> wrote, In part:
> Your final paragraph about the lowered and raised ailerons is either totally incorrect or is simply worded in a way you didn't mean, because the drag you talk about is actually backwards.<
You were referring to my earlier saying this:
"I stand by my theory for now:
Somehow the bank must be creating more drag on the lower wing (or less on the raised wing) creating the turning force.
My guess is the raised aileron on the lower wing -- being in the
different airflow of the upper wing surface -- creates MORE drag on
the lower wing than the lowered aileron on the raised wing does. "
---
Well I may be wrong about the raised aileron on the lowered wing creating more drag on that wing, but if so I'm in some pretty good and credible company in believing that.
See the file "Yaw when banking aircraft.doc " that I just uploaded to our files area.
Or just go to --
http://www.decodedscience.com/side-effect-of-rolling-an-airplane-aircraft-yaw/7209 .
In part what it says there is --
"1. An aircraft initiates a roll to its left.
2. The left aileron (attached to the wing) goes up to produce drag.
3. The right aileron moves downward to produce more lift.
4. As a consequence of increased drag on the left wing, and increased lift on the right wing, the left wing rolls downward while the right wing rolls upward.
5. During this phase (with the left wing down and the right wing up), the right wing travels faster through the air and contributes more to the production of lift.
6. This increased lift acts diagonally and is divided into two components. The horizontal component of lift enables an airplane to roll in the desired direction.
7. The increased production of lift due to the right wing's relatively higher airspeed and its aileron in down position induces an aircraft yaw towards the left. "
Sounds like basically what I said.
The aeronautical credentials of the author (see the site) are good, and it makes sense to me.
So, I'm sticking with the "more drag on the lowered wing is applying the yaw (turning) force" for now.
Alex
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