Sunday, June 17, 2012

Crosswind Landings - Techniques: Crab, Sideslip and De-Crab

The Crab Technique


What is a crosswind landing? Think of wind blowing at right angles to the runway. Thats a true crosswind. In real life it is the component of a crosswind that is considered perpendicular to the runway. If a wind is at a 45 degree angle to the runway there is a vector component  perpendicular to the runway that determines the way a pilot plans his crosswind technique for landing.

Crab Technique:

The idea is,at the moment of touchdown, the axis of the plane is aligned with the center of the runway without drift.

If drifting across the runway takes place when your wheels touch the runway, damage to the aircraft can occur if you don't correct the drift.

The "Crab Technique" the plane makes a coordinated turn into the crosswind to stop the lateral movement of the plane and align the plane with the center of the runway while descending to land. A sideslip is not used.

On normal dry runway surfaces at touchdown the wheels track towards the windward side of the runway while the pilot de-crabs to align the plane with the center of the runway. Forward momentum aids in the effort to align the plane. Use  the upwind aileron to keep the wings level and the rudder to keep the plane aligned to the runway.

It is important to first make a coordinated turn into the crosswind. Maintain the plane level all the way to touchdown. Timing, of course, is important.