What is reference groundspeed?

Reference groundspeed is defined as the expected groundspeed on final approach at approach speed in no wind conditions. This metric is significant in aviation as it provides a baseline for pilots to gauge their approach performance and manage their descent accurately. Knowing the reference groundspeed allows pilots to approach and land safely by understanding the speed at which they should ideally be flying (considering no wind).

In practice, this information can be used to make adjustments during the final approach depending on the current wind conditions and actual groundspeed. It serves as a comparative standard for pilots to assess whether they are maintaining an appropriate speed for safe landing, considering factors such as lift, drag, and runway conditions.