How is "Ground Roll" defined in aviation?

"Ground Roll" refers to the distance traveled by an aircraft along the runway while it is still on the ground and before it becomes airborne. This distance is a critical aspect in flight performance calculations as it encompasses the aircraft's acceleration from a standstill until it lifts off.

Understanding ground roll is essential for pilots, as it factors into takeoff performance, runway requirements, and safety margins. The aircraft's weight, engine power, wind conditions, and runway surface can all influence this distance. Ensuring that there is sufficient ground roll available is vital for safe operations, especially when taking off from a runway that may be shorter than ideal.

The other definitions presented do not align with the specific implications of ground roll: they pertain to different phases of flight or distances not specifically related to the moment just before takeoff. Ground roll specifically encapsulates the final acceleration on the runway leading to takeoff, highlighting its importance in aircraft performance.