Originally Posted by
ryan1234
I'm not sure I understand what it is you're asking, but I'll try to start from scratch and explain as best as I can...
We know that... during a steady, coordinated turn that lift is inclined to produce a horizontal component of lift equal to the centrifugal force in the turn. ... a steady turn is achieved by producing a vertical component of lift equal to the weight of the airplane. If either one of these values do not equal the respective value (i.e. horizontal lift does not equal centifugal force, etc) the airplane will be out of symmetry and some type of acceleration (either positive or negative) will occur (i.e. uncoordination, etc).
I think what you're trying to get at is static stability and dynamic stability. If it is please let us know... that's a whole 'nother topic.
I am responding to UAL who said:
"The horizontal force from the horizontal component moves the airplane at the same rate as the change in direction of flight (and therefore, relative wind), such that there is never any yaw."
What I am confirming is that horizontal lift changes the direction of motion (flightpath), but without a sideforce, the aircraft will not turn, it will only fly sideways. There needs to be something to turn the aircraft around the vertical axis and horizontal lift by itself will not move the aircraft in a circle. The change in the relative wind due to horizontal lift causes a side force to act on the side of the aircraft (behind the c.g.) which causes the plane to turn into the relative wind around the vertical axis.
The turn around the vertical axis has to occur after the change in relative wind, since it is the cause of the other.