Definition
An unwanted sideways skidding or jumping motion of the airplane's main wheels during the takeoff roll, typically caused by a crosswind acting on the airplane while the pilot has not applied enough aileron into the wind to keep the upwind wing down.
Plain English
When a crosswind pushes the airplane sideways across the runway during takeoff because the pilot isn't holding the controls correctly to counter the wind.
Context Anchor
Encountered during the takeoff roll, especially when taking off with wind blowing across the runway.
Derivation
A plain compound: 'side' (sideways) plus 'skipping' (small, repeated jumps or skids). It describes exactly what the tires do — they hop or scuff sideways across the pavement instead of tracking straight.
Why Pilots Care
Uncorrected side-skipping can lead to loss of directional control and a runway excursion.
Intuition Check
Do not read “side-skipping” as a planned maneuver. Here it means an unwanted sideways motion during the takeoff roll that shows the airplane is not tracking properly.
Example Sentence 1
As the crosswind picked up, the student felt the airplane begin side-skipping down the runway and the instructor reminded him to add more aileron into the wind.
Example Sentence 2
If side-skipping begins, the pilot should reduce power and use rudder and brakes to maintain the centerline.