Originally Posted by
ryan1234
What is turning the airplane is the constant force of lift acting completely 'upwards' in relation to the aircraft's reference. The sum of the lift and thrust vectors are what make the 'turn'. Part of the lift force happens to be in a horizontal direction.
Incorrect or not, here is an analogy to help you see where I am coming from. If you were pushing a shopping cart forward, with wheels that caster, while I was pulling the middle side of the cart, 90 degrees to your force, the cart would not turn in a circle like an aircraft does -- the cart would only be moving in a steady new direction to the left or right of the original path. If its not obvious, I am comparing the redirection of the lift vector with "me pulling on the cart".
This is why I thought the weather vane effect was needed as the redirection of lift only explains the change in flight path to me --not actual rotation around any axis.
To confuse matters, the center of pressure is usually located aft of the center to gravity therefore lifting pressure wouldn't rotate you in the direction you want to go anyways.