Which instrument provides information on the aircraft's relative velocity through the air?

• A. Airspeed indicator
• B. Attitude indicator
• C. Heading indicator
• D. Vertical speed indicator

Answer: (A)

The airspeed indicator is specifically designed to provide information about the aircraft's relative velocity through the air. This instrument measures the dynamic pressure of the air passing over the aircraft, which corresponds to the speed at which the aircraft is moving through that air.

By indicating the airspeed, the instrument allows pilots to more effectively manage flight performance, ensuring they maintain safe and efficient operating speeds. This is crucial for takeoff, landing, and throughout various phases of flight, as it affects control, stability, and fuel efficiency.

In contrast, the other instruments don't provide this information. The attitude indicator displays the aircraft's orientation relative to the horizon, the heading indicator shows the direction the aircraft is facing relative to North, and the vertical speed indicator indicates the rate of climb or descent, but none of these convey the speed at which the aircraft is moving through the air.