Which instrument is primarily used for maintaining vertical speed during a climb or descent?

The vertical speed indicator (VSI) is the primary instrument used for maintaining vertical speed during a climb or descent. It provides pilots with real-time feedback regarding their vertical rate of climb or descent, measured in feet per minute. This information is crucial for pilots to manage their altitude change effectively, ensuring they achieve a desired rate of ascent or descent while maintaining safe flight parameters.

The VSI uses a delicate sensing system that measures changes in air pressure as the aircraft ascends or descends. When the helicopter climbs, the pressure decreases, and when it descends, the pressure increases. This change is then displayed to the pilot, allowing for precise control throughout the climb or descent phases of flight.

Properly utilizing the VSI is essential for maintaining the correct flight path and altitude, particularly in crowded airspace or during critical phases of flight. Therefore, understanding how to read and interpret the VSI is a key skill for pilots.