What is the function of the vertical speed indicator (VSI)?

The vertical speed indicator (VSI) plays a crucial role in providing pilots with immediate feedback on the rate of climb or descent of the aircraft. Specifically, it indicates how many feet the aircraft is ascending or descending each minute. This information is vital for pilots during ascents and descents, allowing them to maintain safe operations, manage their approach and landing, or even adjust their flight path during cruising.

Understanding the rate of climb or descent helps pilots ensure they are operating within the optimal parameters for their flight, which enhances overall flight safety and efficiency. Other instruments, such as the altimeter, are utilized for altitude readings, while the artificial horizon indicates orientation relative to the horizon, and the directional gyro shows heading. Each of these instruments serves distinct purposes, highlighting the unique function of the VSI in communicating vertical movement specifically.