Which instrument primarily indicates vertical movement relative to the earth?

• A. The attitude indicator.
• B. The vertical speed indicator (VSI).
• C. The heading indicator.
• D. The airspeed indicator.

Answer: (B)

How fast the aircraft is moving up or down is what this instrument shows. The vertical speed indicator measures the rate of climb or descent, expressed in feet per minute, so you’re aware of how quickly you’re gaining or losing altitude. It doesn’t tell you your altitude itself, just how fast that altitude is changing.

This is different from the attitude indicator, which shows the aircraft’s orientation relative to the horizon (pitch and bank); the heading indicator, which shows direction; and the airspeed indicator, which shows speed through the air. The vertical speed indicator is specifically about vertical movement relative to the earth, not orientation, direction, or forward airspeed.