What Is Ground Speed? Definition & Meaning in Aviation
Ground speed is an aircraft’s speed over the ground, in other words how quickly it is actually covering distance.
In plain language
It equals the speed through the air plus or minus the wind. A tailwind raises ground speed and a headwind lowers it. Flight trackers show ground speed from GPS data.
Example
The same aircraft can show a ground speed hundreds of kilometres per hour higher with a strong jet-stream tailwind.
Why it matters
Ground speed is the speed you see on trackers, and it is what determines arrival time. It can differ greatly from the speed through the air when strong winds blow.