crab

When wind pushes an aircraft perpendicular to its intended track, pilots crab by pointing the nose into the crosswind while the fuselage moves sideways across the ground. The aircraft's heading and its ground track no longer align. A pilot flying a straight northbound approach while a west wind blows will angle the nose northwest, holding that crab angle until touchdown or until the wind condition changes.

Crabbing is essential in crosswind landings, where runway orientation is fixed but wind direction is not. On final approach, the pilot maintains a crab angle that keeps the aircraft aligned with the runway centerline relative to the ground. Without crabbing, the plane would drift downwind and potentially touch down sideways, risking gear damage or loss of directional control. Glider pilots use crabbing during ridge soaring to stay in lift bands that are misaligned with the wind direction.

Where crabbing differs from slipping

In a slip, the pilot deliberately yaws the aircraft to increase drag and lose altitude without gaining airspeed. Crabbing, by contrast, is an attitude correction that maintains safe flight geometry while compensating for wind. A slipped approach feels uncoordinated by design; a crabbed approach should feel coordinated until the final flare.

Modern aircraft with good aileron authority can transition from crab to alignment just before touchdown using a forward slip, a technique called de-crabbing. Larger aircraft or those with limited crosswind capability may land in a small crab and allow the main gear to touch first. Amphibious aircraft landing on water often maintain a crab to align with swell direction, which may differ from wind.

The term originates from the crab's sideways locomotion. In aviation it dates to the early gliding era when ridge soaring over uneven terrain required pilots to hold constant crab angles to stay in rising air. The concept applies equally to ships navigating tidal currents and was borrowed into aviation vocabulary by the 1930s.