Response
Manipulation of the equations of motion yields a second order homogeneous linear differential equation in the angle of attack :
The qualitative behavior of this equation is considered in the article on directional stability. Since and are both negative, the damping is positive. The stiffness does not only depend on the static stability term, it also contains a term which effectively determines the angle of attack due to the body rotation. The distance of the center of lift, including this term, ahead of the centre of gravity is called the maneuver margin. It must be negative for stability.
This damped oscillation in angle of attack and yaw rate, following a disturbance, is called the 'weathercock' mode, after the tendency of a weathercock to point into wind.
Read more about this topic: Stability Derivatives
Famous quotes containing the word response:
“From time to time I listen to what you are saying, just in case a response is needed.”
—Mason Cooley (b. 1927)
“... the most extreme conditions require the most extreme response, and for some individuals, the call to that response is vitality itself.... The integrity and self-esteem gained from winning the battle against extremity are the richest treasures in my life.”
—Diana Nyad (b. 1949)
“Eyes seeking the response of eyes
Bring out the stars, bring out the flowers,
Thus concentrating earth and skies
So none need be afraid of size.
All revelation has been ours.”
—Robert Frost (1874–1963)