Definition
A takeoff initiated from a surface other than the one assigned or intended by air traffic control or the pilot's plan — most commonly a taxiway mistaken for a runway, or a runway different from the one cleared for takeoff. It is a category of surface event tracked by the FAA as a serious safety risk at airports.
Plain English
Beginning a takeoff from the wrong piece of pavement — usually a taxiway instead of a runway, or a runway you weren't cleared to use.
Context Anchor
Pilots encounter this risk while taxiing, lining up for departure, confirming a runway clearance, or checking airport signs and markings before takeoff.
Why Pilots Care
Creates an immediate safety hazard because the chosen surface may be too narrow, lack proper markings, or place the aircraft in conflict with other traffic.
Grounding Statement
The key idea is simple: before takeoff, the pilot must be sure the airplane is on the exact surface intended for departure.
Intuition Check
Do not read “wrong-surface” as meaning only a rough or damaged surface. In this term, it means the incorrect runway, taxiway, or airport surface for the takeoff.
Example Sentence 1
To prevent a wrong-surface takeoff, the pilot confirmed the runway number painted on the threshold matched the takeoff clearance before advancing the throttle.
Example Sentence 2
Clear communication with the tower prevents a wrong-surface takeoff when the assigned runway is changed at the last minute.