What is defined as the "ground roll" in aviation?

The term "ground roll" in aviation specifically refers to the distance an aircraft travels along the runway during the takeoff phase before it becomes airborne. This distance includes the entire interval from the moment the aircraft begins its takeoff roll until it leaves the ground. Understanding this concept is crucial for pilots, as it relates to runway length requirements, aircraft performance calculations, and the effects of factors such as weight, wind, and runway surface conditions.

In contrast, the altitude reached after takeoff relates to the aircraft's vertical ascent once airborne, the speed of the aircraft during landing pertains to the aircraft's approach and landing dynamics, and the duration of time on the runway considers how long the aircraft occupies the runway during takeoff or landing but does not define the 'ground roll' itself. Each of these other definitions focuses on different aspects of flight and operation rather than the specific distance covered while the aircraft is still in contact with the runway.