What is the expected sink rate (VSI) at the best glide speed?

The expected sink rate (Vertical Speed Indicator, VSI) at the best glide speed is typically around 1350 to 1500 feet per minute. This range indicates how quickly the aircraft will descend when flying at the optimal speed to maximize glide distance. At best glide speed, the aircraft is at a configuration that minimizes drag and optimizes lift, allowing for the best possible performance in terms of glide ratio.

Flying at this speed enables the pilot to achieve the maximum distance per altitude lost, which is crucial during emergency landings or for managing flight in an area of turbulence. Understanding the sink rate is essential for making informed decisions about approaches to landing, navigation, and managing aircraft performance in various conditions. Thus, the range of 1350 to 1500 fpm is significant for pilots to anticipate descent rates and plan their maneuvers effectively.