Plain English Meaning

How fast the aircraft is actually moving over the ground while going down. It's not how fast you're going through the air — it's how fast the runway is approaching beneath you, taking the wind into account.

Full Definition

The aircraft's speed across the ground during a descent, measured in knots and used to calculate how far the aircraft will travel during the descent and how long the descent will take. Descent groundspeed is true airspeed adjusted for the wind component along the flight path, and it is the value used in descent planning calculations such as top-of-descent point and rate of descent in feet per minute.

Context Anchor

Used in instrument descent planning when deciding when to down and how fast to descend.