Turning an airplane question

ktsai91

Well-Known Member
When turning an airplane in flight, I heard that I need to use both alierons AND rudder. Why is it that way? Can't I only use alierons instead? Usually, when playing in my FS2004, I use the alierons only. I think alieron and rudder makes turning harder.
 
#1 rule of aviation: Flight simulator is *nothing* like real-world flying. :)

You must use both rudder and aileron for coordinated flight. FS has a function called "auto-rudder" which eliminates the need for a rudder, but that is far from reality. Flight simulator is a good tool for instrument flying, but as far as actual flight dynamics, FS does more harm than good.
 
How do the ailerons work?

Well, when you roll right, the left aileron goes down and the right one goes up. The left aileron going down increases lift on the left wing, causing it to rise. Any time you increase lift, you increase drag. Therefore, using aileron to lift the left wing causes an increase in drag on the left wing. If you have more drag on the left wing than on the right, what happens? Well, the nose of the aircraft wants to swing left. You have to use right rudder to keep it from doing that.

You won't notice this much in FS though. The best way to see this is to be in a real airplane and slow it way down (in the 172, 55-60 knots). Then, crank in full aileron and no rudder. The nose will swing WAYYY over to the opposite direction. Then go full aileron the other way, no rudder. Keep alternating back and forth. It's pretty uncomfortable, but you'll know what adverse yaw is all about after that.

*edit* this should probably be in the CFI Corner or Technical Talk.
 
How do the ailerons work?

Well, when you roll right, the left aileron goes down and the right one goes up. The left aileron going down increases lift on the left wing, causing it to rise. Any time you increase lift, you increase drag. Therefore, using aileron to lift the left wing causes an increase in drag on the left wing. If you have more drag on the left wing than on the right, what happens? Well, the nose of the aircraft wants to swing left. You have to use right rudder to keep it from doing that.

You won't notice this much in FS though. The best way to see this is to be in a real airplane and slow it way down (in the 172, 55-60 knots). Then, crank in full aileron and no rudder. The nose will swing WAYYY over to the opposite direction. Then go full aileron the other way, no rudder. Keep alternating back and forth. It's pretty uncomfortable, but you'll know what adverse yaw is all about after that.

*edit* this should probably be in the CFI Corner or Technical Talk.

Thanks for the info! And sorry if I didn't put the thread in the CFI Corner or Technical Talk. I didn't know that.
 
Hey no problem. This phenomenom is called "Adverse Yaw" and it's amazing how few pilots truly understand it. If you watch the nose for yaw when rolling in and out, it's amazing how easy it is to see proper and improper use of the rudder.

As a newbie, be aware that proper use of the rudder is one of the things that is most commonly missed things for any level of pilot.
 
How do the ailerons work?

Well, when you roll right, the left aileron goes down and the right one goes up. The left aileron going down increases lift on the left wing, causing it to rise. Any time you increase lift, you increase drag. Therefore, using aileron to lift the left wing causes an increase in drag on the left wing. If you have more drag on the left wing than on the right, what happens? Well, the nose of the aircraft wants to swing left. You have to use right rudder to keep it from doing that.

You won't notice this much in FS though. The best way to see this is to be in a real airplane and slow it way down (in the 172, 55-60 knots). Then, crank in full aileron and no rudder. The nose will swing WAYYY over to the opposite direction. Then go full aileron the other way, no rudder. Keep alternating back and forth. It's pretty uncomfortable, but you'll know what adverse yaw is all about after that.

*edit* this should probably be in the CFI Corner or Technical Talk.

Oh yeah that's a great demo... just whatever you do, don't sleep in the back of a 172 with the seat reclined when the PIC decides to "demo" adverse yaw for fun... :(
 
Therefore, using aileron to lift the left wing causes an increase in drag on the left wing. If you have more drag on the left wing than on the right, what happens? Well, the nose of the aircraft wants to swing left. You have to use right rudder to keep it from doing that.

This is the FAA's watered down version of adverse yaw.

In a right turn, the descending wing experiences a relative wind that approaches from ahead and below the wing since the wing is simultaneously moving down and forward. Lift, which always acts perpendicular to the relative wind, causes the lift vector to lean forward to an extent which in essence 'pulls' the descending wind forward.

In essence, when a pilot banks into a turn, it is the force of lift (as you described) that 'pulls' forward on the wing and conversely, 'pulls' back on the ascending wing. The one thing pilots tend to over-look or accept is the FAA's elementary definition rather than really understanding the dynamics or mechanism behind such phenomenon as adverse yaw.
 
One thing I've noticed about the aerodynamics of flight, is that there are often multiple reasons for one behavior of an aircraft. Often, it seems that these multiple reasons all add to each other, such as this with the combination of increased drag on the left wing and the change in relative wind on the right wing.
 
This is the FAA's watered down version of adverse yaw.

In a right turn, the descending wing experiences a relative wind that approaches from ahead and below the wing since the wing is simultaneously moving down and forward. Lift, which always acts perpendicular to the relative wind, causes the lift vector to lean forward to an extent which in essence 'pulls' the descending wind forward.

In essence, when a pilot banks into a turn, it is the force of lift (as you described) that 'pulls' forward on the wing and conversely, 'pulls' back on the ascending wing. The one thing pilots tend to over-look or accept is the FAA's elementary definition rather than really understanding the dynamics or mechanism behind such phenomenon as adverse yaw.
I've not heard that before. It makes sense, but I would argue that in teaching a private student, the more intuitive (while STILL CORRECT) explanation that I gave may be more practical.
 
In a right turn, the descending wing experiences a relative wind that approaches from ahead and below the wing since the wing is simultaneously moving down and forward. Lift, which always acts perpendicular to the relative wind, causes the lift vector to lean forward to an extent which in essence 'pulls' the descending wind forward.

This isn't a watered down version, but is a real phenomenon, and probably of more significance than differential drag of the ailerons, at least in modern airplanes. Note this is a *separate* phenomenon from the aileron drag, but both are generally considered part of "adverse yaw".
 
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