Definition
In landing context, the sideways movement of an airplane across the runway caused by a crosswind component acting on the aircraft when it is not being corrected for with rudder, aileron, or crab. Drifting at touchdown imposes side loads on the landing gear and can cause the airplane to depart the runway centerline or sideways across the surface.
Plain English
Drifting is when the wind pushes the airplane sideways across the runway as it touches down, instead of the airplane moving straight along the runway centerline.
Context Anchor
Seen during landing practice, especially in crosswind landings and touchdown discussions.
Derivation
Drift comes from an old word meaning to be driven or carried along. That fits the aviation use because wind can carry the airplane sideways over the ground even while the pilot is trying to land straight ahead.
Why Pilots Care
Uncorrected drifting moves the airplane off the runway centerline and can result in a runway excursion or loss of directional control at touchdown.
Intuition Check
Drifting does not mean the airplane is simply staying in the air longer before touchdown. Here it means the airplane is moving sideways across the runway path.
Example Sentence 1
On final approach in a crosswind, the pilot lowered the upwind wing and applied opposite rudder to stop the airplane from drifting toward the edge of the runway.
Example Sentence 2
A slight crosswind caused the airplane to begin drifting left of centerline just before the wheels touched.