Which instrument provides information about the aircraft's vertical speed?

• A. The attitude indicator
• B. The altimeter
• C. The vertical speed indicator
• D. The airspeed indicator

Answer: (C)

The vertical speed indicator (VSI) is specifically designed to provide information about the aircraft's rate of climb or descent, measured in feet per minute. This instrument utilizes a capsule that changes pressure as the aircraft ascends or descends, translating that change into a visual reading on the dial. Pilots rely on the VSI to gauge how quickly they are gaining or losing altitude, which is crucial for maintaining controlled flight during climbs and descents.

Other instruments listed provide different types of information. The attitude indicator shows the aircraft's orientation relative to the horizon, the altimeter measures the aircraft's altitude above sea level, and the airspeed indicator indicates the aircraft's speed through the air. Each of these instruments serves an essential function but does not measure vertical speed directly, making the vertical speed indicator the correct choice for this question.