Instrument Flying Handbook Menu>Aerodynamic Factors>Lift > Pitch/Power Relationship

An examination of figure 2-4 provides insight into the relationship between pitch and power when it comes to controlling flightpath and airspeed. In order to maintain a constant lift, when the airspeed is reduced, the pitch must be increased. The pilot controls pitch through the elevators, which in effect controls the angle of attack. When back pressure is applied on the elevator control, the tail lowers and the nose rises, thus increasing the wing’s angle of attack and lift.

Figure 2-4. Relationship of lift to angle of attack.

Thrust is controlled by using the throttle to establish or maintain desired airspeeds. The most precise method of controlling flightpath is to use pitch control while simultaneously using power (thrust) to control airspeed. In order to maintain a constant lift, a change in pitch will require a change in power, and vice versa.

If you want the aircraft to accelerate while maintaining altitude, thrust must be increased to overcome drag. As the aircraft speeds up, lift is increased. To keep from gaining altitude, you must lower the pitch to reduce the angle of attack. If you want the aircraft to decelerate while maintaining altitude, thrust must be decreased. As the aircraft slows down, lift is reduced. Then you must increase the pitch in order to increase the angle of attack and maintain altitude.