Definition
The calibrated airspeed at which the airplane first becomes airborne during the takeoff roll — the moment the main wheels leave the runway surface.
Plain English
The speed at which the wheels actually leave the ground on takeoff.
Context Anchor
Seen in takeoff performance, takeoff technique, and FAA discussions of speeds used during the takeoff roll.
Derivation
The 'V' stands for velocity. 'LOF' stands for lift-off. Aviation uses a family of 'V-speeds' (VR, VS, VX, VY, etc.) — each one a specific, defined airspeed for a specific phase of flight.
Why Pilots Care
VLOF determines the point where the airplane transitions from rolling on the runway to climbing, which directly affects runway length requirements and obstacle clearance.
Intuition Check
Do not assume VLOF is the same as rotation speed. Rotation is when the pilot starts raising the nose; VLOF is when the airplane actually leaves the runway.
Example Sentence 1
After rotating at VR, the airplane accelerated for another second before reaching VLOF and lifting off the runway.
Example Sentence 2
Takeoff distance charts show how far the airplane needs to roll to reach VLOF before becoming airborne.