phase of flight in which a vehicle leaves contact with the land or water surface

Takeoff is the part of flight in which an aircraft goes from moving along the ground (taxiing) to flying in the air, usually on a runway. For balloons, helicopters and some special aircraft (such as the Harrier), no runway is needed. Takeoff is the opposite of landing.

An F/A-18 Hornet takes off from the USS Kitty Hawk.