In this Demonstration the static longitudinal stability of an F-16 aircraft is explored. The model (Morelli 1998) is valid in the range: , , and . Again is the angle of attack, is the side-slip angle, and is the elevator deflection. All the angles are in radians and denotes the center of gravity (c.g.) location.

The F-16 is an inherently unstable aircraft. With the c.g. at the reference location of 0.35 and in straight flight (), the aircraft has an unstable equilibrium at . It is not possible to stabilize it with any elevator deflection. With feedback of the angle of attack a feedback law can be implemented. For example, at straight and level flight for , gives a stable trim condition at . The green point signifies that there is sufficient elevator control with this condition. A red point denotes equilibrium points that are saturated. With this feedback law there are two other equilibrium points and , at which the elevator is saturated and the aircraft is unstable as well. This gives a sense of the flight envelope in which the proportional feedback law is feasible. Similarly, various other configurations can be explored.