Definition
The portion of a takeoff or landing during which the aircraft is rolling on the runway surface — measured from brake release to the point of liftoff on takeoff, or from touchdown to full stop on landing. It is one component of total takeoff or landing distance, the other being the airborne segment over a 50-foot obstacle.
Plain English
The distance the aircraft travels along the ground while its wheels are still on the runway — either accelerating to lift off, or rolling out after touching down.
Context Anchor
Seen in takeoff and landing performance discussions, especially when altitude, temperature, runway surface, or aircraft weight changes how much runway is needed.
Derivation
Ground means the surface the aircraft is rolling on. Run comes from an older common use meaning a stretch or course of movement, not necessarily a person running. Together, ground run means the aircraft’s rolling distance along the ground.
Why Pilots Care
It directly affects the minimum runway length needed for safe operations and determines takeoff or landing performance margins.
Grounding Statement
If the airplane accelerates slowly or slows down poorly, the ground run gets longer because it spends more distance rolling on the runway.
Intuition Check
Do not read ground run as an engine run-up or a casual trip across the ground. In this context, it means the runway distance used while the aircraft is rolling on its wheels.
Example Sentence 1
At higher density altitude, the takeoff ground run lengthened noticeably before the aircraft lifted off.
Example Sentence 2
A headwind reduced the aircraft's ground run during landing.