[simpits-tech] Sorry, Gene...

[Andreas Fransson]

This went to the wrong address last time so I'll try again:


Close ... But I'll throw in my 2 cents as well, I think.

It is the downgoing aileron that causes the extra drag, which results in a
yawing motion in the opposite direction from where you're banking the 
aircraft.

For example, if you are banking the aircraft to the left (stick/wheel to the
left), the right aileron goes down (pushing the wing up, and generating the
extra drag as a side-effect). Now the aircraft is banking left, but turning
(yawing) right. A very strange motion I might add.

To counter-act this, you have to apply left rudder as well, to keep the right
wing forward (or the nose turning left). When you coordinate this correctly,
the aircraft will turn left, "centered" on the wings (not slipping sideways).

This is from my glider classes. I don't have any hands-on experience with
motorised aircraft, but from what I've heard, the adverse aileron yaw 
effect is
a lot more pronounced (sp?) in a glider. I suspect this is because of the
proportions of the plane itself, with gliders commonly having wingspans 
between
15 and 20 meters (larger wingspan -> larger torque). Coordinating rudder and
ailerons is a full time job for us glider pilots, as we always strive 
to fly as
clean as possible with minimum amount of drag. We don't have the luxury of
having a fan in front of us, taking us where we want to go ... ;)

This effect is also present with the rudder. When you push hard left or right
rudder, the "outside" wing (the right one in a left hand turn) travels faster
than the other one, creating greater lift, causing it to go up.

I think the "swapping jobs" thing could have been referring to the combination
of these effects.

/Andreas


Citerar Ben Jones <bjones at pipecomp.com.au>:
> I thinks the technical term for this is "adverse aileron yaw" 
> encounted at slow speeds and high angles of attack  its caused by the 
> upgoing aileron creating more drag thus yawing the aircraft , because 
> of the slow speed the down going aileron at high angles of attack 
> doesn't have enough airflow over the wing to creat lift and roll the 
> wing over ......