taxi
The movement of an aircraft across an airport's surface under its own power; a phase of aircraft operation involving this movement.
taxi: aircraft movement on the ground under its own power
Taxiing is the controlled movement of an aircraft across airport pavement using its own engines at low power, typically at speeds between 5 and 15 knots. This phase connects the parking stand to the runway before takeoff, and the runway to the stand after landing. The pilot controls direction using the nose wheel tiller or rudder pedals and manages speed with differential engine thrust and wheel brakes.
Aircraft taxi in two main phases: the inbound taxi from runway to gate, and the outbound taxi from gate to runway. The outbound taxi is usually longer because the pilot must navigate from the parking area through taxiways, which are marked with yellow edge lighting and blue centerline lights at night. Air traffic control issues taxi clearances that specify the exact route, and pilots must read back these clearances to confirm understanding.
Wear on tires, brakes, and landing gear accelerates during taxi operations because the wheels bear the full aircraft weight while friction and steering loads stress the hardware. Overheating of brakes is a real risk, especially during taxi delays on congested aprons in warm weather. Hydraulic systems must maintain sufficient pressure to power the nose wheel steering throughout the taxi, and any loss of steering authority becomes a critical issue on the ground.
The term originates from the taxi dance halls of early twentieth-century urban entertainment, where clients paid for dancing with attendants. Pilots adopted the word because taxiing an aircraft, like a taxi dance, involves controlled movement in a confined social space under rules. The metaphor stuck, possibly because early ground movements appeared similarly choreographed and slow.
In maintenance, taxi damage often goes unnoticed until scheduled inspections reveal cracked wheel rims, brake assembly corrosion, or hydraulic line chafing. Tarmac delays and repeated rejected takeoffs generate excessive taxi cycles, which compress the maintenance interval and increase parts life consumption. Maintenance personnel must track taxi time separately from flight time because ground operations stress the airframe and systems differently than airborne flight.