Which term refers to the capability of an aircraft to respond to the pilot's control, especially with regard to flight path and altitude?

• A. Stability
• B. Maneuverability
• C. Trim
• D. Controllability

Answer: (D)

Controllability is the ability of an aircraft to respond to the pilot's control inputs with changes in flight path and altitude. When controllability is good, small deflections of the controls produce timely, predictable changes in pitch, roll, and yaw, letting you steer toward the desired path and altitude.

Stability describes how the airplane behaves without pilot input, including its tendency to return to straight-and-level after a disturbance. Maneuverability refers to the overall ability to change flight path and attitude, which depends on controllability but emphasizes performing maneuvers rather than just the responsiveness to controls. Trim is about setting aerodynamic forces so the aircraft can maintain a steady flight path with minimal control input, reducing required control effort but not defining how the aircraft responds to control inputs.

So, the term that best fits the capability to respond to the pilot's control, especially regarding flight path and altitude changes, is controllability.