Monday, June 18, 2012

Crosswind Landings - Part Two - De-Crab

The De-Crab Technique


De-Crab is the recovery technique to align the plane with the center of the runway where the vector component of the crosswind is significant.

This technique is different from the Crab Approach which uses a coordinated turn into the crosswind early on to align the flight path of the plane to the center of the runway.

The idea of the De-Crab approach is maintaining level wings with the aircraft in a slightly crabbed position with respect to the centerline of the runway.

This presents a visual illusion that a pilot is presented with as the plane seems to take up a heading with the plane that is different from the actual flight path of the plane.

The position of the plane is controlled by the increased drag force as the plane flies in a "skewed" manner and the application of thrust provided by the engine and propeller.

This allows the plane to approach the flare point with level wings. Just before touchdown opposite rudder is applied gently to align the plane with the center line of the runway and, at the same time, opposite aileron is applied to maintain a level wing approach.

The cross controlling of rudder one way and opposite aileron the other way can increase the angle of attack that, in some cases, could precipitate a stall. Save the cross control effect  until the last moment before touchdown.

If you practice this technique so that at touchdown the plane body, velocity vector and bank angle are all aligned with the runway centerline you have accomplished a successful crosswind landing.

Please consult your Flight Instructor for further refinement of this crosswind technique.