Back-Taxi

Definitions

Backtrack. To taxi on a runway-in-use, in the opposite direction to the aircraft’s take-off or landing direction. (Source: UK CAA - CAP1430)

Back-taxi. A term used by air traffic controllers to taxi an aircraft on the runway opposite to the traffic flow. The aircraft may be instructed to back-taxi to the beginning of the runway or at some point before reaching the runway end for the purpose of departure or to exit the runway. (Source: US FAA - Pilot/Controller Glossary)

Both expressions basically mean the same. While the term backtrack is routed in official ICAO documentation, the term back-taxi was obviously introduced by the US FAA.

Description

At aerodromes with no parallel taxiway or when the parallel taxiway is unusable, aircraft may need to backtrack for both arrival and departure operation.