Stability Derivatives - Response

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:

    Perhaps nothing in all my business has helped me more than faith in my fellow man. From the very first I felt confident that I could trust the great, friendly public. So I told it quite simply what I thought, what I felt, what I was trying to do. And the response was quick, sure, and immediate.
    Alice Foote MacDougall (1867–1945)

    ... 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)

    The reason can give nothing at all Like the response to desire.
    Wallace Stevens (1879–1955)