Definition
An uncoordinated turn in which the airplane's longitudinal axis is not aligned with the flight path. In a slipping turn, the rate of turn is too slow for the bank angle, and the airplane slides toward the inside (lower wing) of the turn. In a skidding turn, the rate of turn is too fast for the bank angle, and the airplane slides toward the outside (higher wing) of the turn. Both conditions are visible on the inclinometer (the ball) being displaced from center.
Plain English
A turn that is not coordinated. In a slip, the airplane is banked more than it is turning, so it slides toward the low side. In a skid, the airplane is turning faster than its bank suggests, so it slides toward the high side. Pilots see this on the small ball in the turn instrument: ball to the inside means slip, ball to the outside means skid.
Context Anchor
Seen in slow flight, stall, and spin-awareness training, especially when discussing turns close to the ground such as the base-to-final turn.
Derivation
Slip comes from the Old English slipan, meaning to slide or glide sideways. Skid comes from a Norse-rooted word meaning to slide on a surface, often without control. Both names describe what the airplane is doing: sliding sideways through the air rather than carving a clean turn.
Why Pilots Care
Uncoordinated flight during a stall can cause the aircraft to enter a spin. Correcting slips and skids keeps the airplane coordinated and reduces spin risk.
Grounding Statement
Picture the airplane trying to follow a curved path while its body is slightly sideways to the airflow instead of cleanly lined up with the turn.
Intuition Check
Do not read “slipping” or “skidding” as just “a bad turn.” In this context, they mean specific kinds of unbalanced turn: a slip is too much bank or too little rudder, while a skid is too much rudder or too little bank.
Example Sentence 1
The instructor pointed out that the student was entering a skidding turn from base to final, with the ball pushed to the outside, and reminded him to add right rudder to coordinate.
Example Sentence 2
During a stall recovery exercise the instructor created a slipping turn by holding too much bank without enough rudder.