What is the purpose of a vertical speed indicator in an aircraft?

The vertical speed indicator (VSI) is an important instrument in an aircraft that provides real-time information about the rate of climb or descent. This is essential for pilots to maintain proper altitude during flight operations. The VSI measures the change in altitude over time, typically displayed in feet per minute, helping pilots understand whether they are climbing, descending, or maintaining level flight.

Understanding vertical speed is crucial for flight safety and effective management of altitude, especially during takeoff, landing, and when making altitude adjustments. By providing immediate feedback on vertical movement, the VSI allows pilots to make necessary adjustments to the aircraft's pitch and power settings, contributing to smoother and safer flight operations.