What type of information does the VSI display?

The Vertical Speed Indicator (VSI) is specifically designed to display the rate of climb or descent of the aircraft. This instrument provides critical real-time information to the pilot, indicating how quickly the aircraft is ascending or descending, usually expressed in feet per minute. This information allows pilots to make informed decisions about their altitude adjustments during flight, ensuring safety and maintaining desired flight profiles.

The VSI works by measuring changes in the static pressure in the atmosphere as the aircraft ascends or descends. When an aircraft climbs, the static pressure decreases, and when it descends, the pressure increases. The VSI translates these pressure changes into a visual representation for the pilot, enabling them to maintain control over their vertical speed effectively.