Other Maneuvers

Longitudinal maneuvering implies changing the altitude of the aircraft and changing the direction (flight path angle) and magnitude (airspeed) of the velocity vector. Pitch altitude variation is achieved by deflecting the (aerodynamic) control surface on the horizontal tail of the aircraft. The magnitude change in the velocity is affected by operating the thrust level of the engines and a small change in the pitching motion. The direction of the velocity vector is changed by a variation in the lift vector through altitude variation. Lateral maneuvering is affected by rolling the aircraft about its longitudinal axis by deflecting ailerons or elevons as the case may be (e. g., for a delta wing aircraft the elevators and ailerons are on the rare ends of the wing and are called elevons). The differential movements of end-elevons give rise to a rolling moment about the pitch axis of the aircraft.

Aircraft’s maneuverability is defined as the ability of an aircraft to change the speed and flight (-path) direction. A highly maneuverable aircraft can accelerate or slow down (SD) very quickly. However, a quick maneuver with a short radius would induce high loads on the wings, referred to as ‘‘g-force.’’

In equilibrium condition, the thrust is equal to the drag force, so that the aircraft is stabilized in level flight with a constant speed. As per Newton’s laws, the aircraft continues to fly with constant speed, unless there is some additional force of disturbance. Now, if the throttle is advanced to obtain full power from the engine, the thrust exceeds the drag force, and this excess force accelerates the aircraft because force = mass x acceleration. The aircraft will speed up due to accelerating force and stabilize; when the excess thrust becomes zero, the aircraft reaches its maximum speed. The importance of excess thrust is that it can be used either to accelerate the aircraft to a higher speed or to enter a climb at a constant speed or a combination of both (Exercises 7.9 and 7.10). However, with an increase in speed, if the pilot does not want the aircraft to climb, then he or she has to lower the elevator (so the inclined/upward force acting on the elevator generates a nose down moment of the aircraft) by pushing the stick forward.