Definition
The portion of the takeoff during which the airplane accelerates along the runway surface from a standstill until the wheels leave the ground at liftoff.
Plain English
The part of takeoff where the airplane is still rolling on the runway, from the moment power is applied until the wheels lift off.
Context Anchor
Used in takeoff technique and runway planning, especially when judging how much runway the airplane needs before becoming airborne.
Derivation
“Takeoff” means the act of leaving the ground. “Roll” here comes from the airplane moving on its wheels along the surface. Together, the phrase points to the runway-moving part of the takeoff, before flight actually begins.
Why Pilots Care
It determines the minimum runway length required for a safe takeoff and is essential for performance planning in varying conditions such as density altitude or surface wind.
Intuition Check
Do not confuse “roll” here with turning or banking the airplane. In “takeoff ground roll,” it means the airplane rolling forward on its wheels before liftoff.
Example Sentence 1
On a hot day at high elevation, the takeoff ground roll was noticeably longer than the chart values predicted at sea level.
Example Sentence 2
A headwind shortened the takeoff ground roll, allowing the airplane to become airborne sooner than on a calm day.