Instrument Rating Checkride Practice Test

The main function of the Vertical Speed Indicator (VSI) during taxi prior to takeoff is to indicate a climb rate of 0 feet per minute (fpm). When taxiing on the ground, the aircraft should be level and stationary, indicating that there is no vertical motion. The VSI is designed to reflect changes in vertical speed, and a reading of 0 fpm confirms that the aircraft is neither climbing nor descending, which is the expected condition during taxiing.

This is particularly useful for pilots to ensure that the aircraft is in a stable state before initiating takeoff. If the VSI shows any significant deviation from 0 fpm while taxiing, it may indicate an error or miscalibration that requires attention before departure. The VSI does not provide altitude readings, navigation information, or monitor fuel efficiency during this phase, indicating that it is specifically designed to address vertical movement and thus is of utmost importance for confirming a proper stance on the ground prior to flight.