Which flight instrument is used to establish a rate of ascent or descent, or to maintain level flight?

• A. Altimeter
• B. Vertical speed indicator
• C. Attitude indicator
• D. Rate of climb indicator

Answer: (D)

Controlling vertical motion relies on an instrument that shows how fast the aircraft’s altitude is changing. The rate of climb indicator provides this vertical speed, typically shown in feet per minute, telling you how quickly you’re ascending or descending. Because you can see the exact rate, you can set a desired climb or descent and adjust pitch and power to achieve it. If you want level flight, you aim for a vertical speed near zero, which indicates you’re neither climbing nor descending.

Altimeter measures altitude but not how fast you’re changing it, so it doesn’t directly help you manage rate. The attitude indicator shows the aircraft’s orientation, not vertical speed. The vertical speed indicator serves the same purpose as the rate of climb indicator—indicating change in altitude over time—but the option highlighted emphasizes the rate-of-change aspect you actively control to maintain a chosen vertical profile.