IVSI is an acronym for which aviation instrument?

• A. Instantaneous Vertical Speed Indicator
• B. Indicated Vertical Speed Instrument
• C. Intermittent Vertical Speed Indicator
• D. Integrated Velocity Speed Indicator

Answer: (A)

IVSI stands for Instantaneous Vertical Speed Indicator. This instrument shows the current rate at which the aircraft is climbing or descending, typically in feet per minute. It derives its reading from changes in the static pressure in the pitot-static system and translates that rate of pressure change into vertical speed. The “instantaneous” part means it responds promptly to changes in flight path, so when you pitch up or down or change power, the indicator reflects that new rate quickly (with only the inherent mechanical lag). Other named options aren’t standard aviation terms for this instrument, so the correct interpretation is that IVSI is the instantaneous vertical speed indicator.