skid

A skid occurs when an aircraft sideslips with its nose pointed toward the inside of the turn, the opposite geometry of a slip. The aircraft's direction of travel (relative wind) no longer aligns with its longitudinal axis. In a skid, the low wing is on the inside of the turn, but the nose points further inward still, so the fuselage is crabbed sideways through the air. This happens most often when a pilot applies too much rudder relative to aileron input during a turn, or when recovering from a slip with abrupt control inputs.

The aerodynamic signature of a skid differs fundamentally from a slip. In a skid, the aircraft experiences centrifugal force that exceeds the vertical component of lift, so the outer wing wants to lift. A slip, by contrast, occurs when the inner wing is held down deliberately, and the relative wind comes from a flatter angle. Pilots sometimes confuse the two because both produce a sideways sensation and require cross-control inputs to recover, but they demand opposite corrections.

Recognition and Recovery

Skids are recognizable on approach by a sideways drift, a nose-inboard attitude, and rising g-load. The turn coordinator shows a rate needle deflected away from the bank indicator. In pronounced skids, passengers report feeling thrown outward; the outer wing-tank fuel gauge reads high due to g-loading. Recovery requires reducing rudder pressure (not increasing it further) and rolling out gently with ailerons. Aggressive rudder application during recovery can deepen the skid and lead to a secondary stall if the aircraft is slow.

Skids matter most during crosswind landings and slow flight training. An aircraft held too tightly in a crosswind crab, then corrected with excessive inside rudder, will skid toward the runway. Light aircraft are especially prone to skids because short fuselages make cross-control inputs feel abrupt. Heavy jets, which have longer response lags, skid less often but can enter a skid if autopilot mode coupling occurs during a turn at altitude.

The term "skid" itself refers to the sliding motion of the aircraft's center of gravity outward relative to its heading. It is not related to landing skids or skid gear, though those terms share etymology. In maintenance, skid reports typically flag instrument or control rigging issues: a turn coordinator that lags, rudder cable tension out of limits, or aileron-rudder interconnect malfunction. Recurrent skids on approach warrant a check of the aircraft's lateral trim tab and roll authority, particularly in high-wing designs where control harmony is sensitive.