Which instrument is used to measure an aircraft's angle of attack?

The angle of attack indicator, or AOA meter, is the instrument specifically designed to measure the angle between the chord line of the wing and the relative wind. This measurement is crucial for understanding the aerodynamic performance of the aircraft, particularly in terms of stall characteristics and lift generation.

The angle of attack is a key factor in maintaining safe flight. By knowing the angle of attack, pilots can make informed decisions regarding lift and the potential onset of a stall. The AOA meter provides real-time feedback, allowing pilots to adjust their flying techniques as necessary, especially during critical phases of flight such as takeoff and landing.

In contrast, other instruments like the airspeed indicator, attitude indicator, and vertical speed indicator serve different purposes: the airspeed indicator shows the speed of the aircraft relative to the air; the attitude indicator provides information on the aircraft's orientation relative to the horizon; and the vertical speed indicator indicates the rate of climb or descent. None of these instruments measure the angle of attack directly, making the angle of attack indicator the essential tool for that specific function.