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Crosswinds!!

During crosswind takeoffs: In this example, the wind will be from the left.  The airplane will start the takeoff roll with the ailerons fully deflected into the wind, for this example, full left deflection.  Directional control is maintained with the rudder during the takeoff roll.  During the roll, airspeed increases, making the controls become more effective requiring less input, so the aileron input should be gradually reduced.  At rotation speed, the first wheel to leave the ground is the nose wheel.  The downwind wheel (in this example the right wheel) will be lifted second, since the ailerons are still deflected toward the left, keeping the upwind wheel (left wheel) firmly on the ground until liftoff is complete.  Once all the wheels are off the ground, the ailerons will be neutral, with slight right rudder to counteract left-turning tendencies.  However, with neutral control inputs, the airplane will begin to drift downwind (to the right in this example).  To counteract this and perform a maximum-rate-of-climb, the airplane must be crabbed into the wind.  This crab, known as the wind correction angle, keeps the airplane’s wing at 0° bank, allowing a maximum rate of climb.  To establish a crab, make a coordinated turn into the wind by using left aileron and releasing right rudder (you still have to counteract left turning tendencies) until the desired track across the ground (course) is maintained.  The difference between the heading (where the nose is pointed) to the course (what the track across the ground is) is the crab angle or wind correction angle.  When the crab is properly executed, the bank will be 0° and the ailerons will be neutral, with only slight right rudder to counteract the left turning tendencies.

During Crosswind Landings: In this example, the wind will be from the left.  While on final approach, a different method of counteracting the wind must be used.  Because the nose of the airplane must be pointed in the same direction as the landing runway, a side-slip must be used to effectively counteract the effects of crosswind.  If a crab were used during touchdown, the wheels would be subject to side-load and could collapse.  Additionally, if a touchdown was attempted with a crab, as soon as the wheels were on the ground, the airplane would immediately begin traveling in that direction.  So if the nose of the airplane were pointed at the edge of the runway but the track of the airplane was straight down the runway, as soon as the wheels touched the airplane would run off the edge of the runway.

Therefore, the side-slip must be used.  While on final approach, the nose of the airplane is aligned with the runway by using rudder, and drift is counteracted by using ailerons.  In strong crosswinds, this results in a pronounced cross-controlled situation, creating a lot of drag.  To prevent a loss of airspeed, slightly more power must be used compared to a normal approach and the nose must be lowered more than normal.  For this example, during approach, to establish a side-slip, left aileron must be used and right rudder.  If only left aileron were used, the airplane would eventually turn left.  To prevent this turn, right rudder must be used.  What results is a slight bank to the left, allowing the upwind wheel (left in this example) to touch the ground first.  In order to keep the left wheel/wing low during approach as the flare is started, control deflection must increase because as airspeed is decreased, controls become less effective.  Once the upwind wheel is firmly on the ground, the downwind wheel (right in this example) touches second.  This occurs because of the reduction in speed, causing the controls to become less effective.  As the forward momentum decreases after initial contact, the weight of the airplane will cause the downwind wheel to gradually settle onto the runway.  Directional control is maintained throughout touchdown and rollout with rudder.  Once the nose-wheel is firmly on the ground and the rollout is started, the aileron control is continually increased.  Once safe taxi speed is reached, full aileron deflection should be used.

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