Continuing Ed

The key to pleasing crosswind landings

Aerobatic pilots do it, and do it a lot. Straight-and-level, right-side-up pilots do it, too, although far less often. What we do is cross-control--turn the yoke or deflect the stick one way, push the rudder the other. Although in normal flight it's done infrequently, intentionally cross-controlling an airplane in specific situations is a challenging and rewarding skill to have in your personal tool chest.

Pilots are taught from the get-go to use the rudder pedals in concert with the yoke to make comfortable, coordinated turns. To make a level, 45-degrees-of-bank turn to the left, for example, twist the yoke counterclockwise to achieve the desired bank angle, pull back slightly to keep the nose from dropping below the horizon, and apply left rudder to overcome adverse yaw--the nose slewing right because of the increased drag of the up (right) wing and decreased drag of the down (left) wing. Nicely coordinated, nicely done, thank you.

The aerobatic pilot has no interest in making coordinated turns for comfort's sake, only in positioning stick and rudder independently to make the airplane pitch, roll, and yaw as necessary to execute the desired maneuver. A level aileron roll to the left, for example, calls for the pilot to first use left (bottom), then right (top), then left rudder aggressively for both yaw and pitch control to keep the nose on point throughout the roll. Meanwhile, the stick is pushed left to bank, and also pulled aft and then pushed forward to keep the nose level as the airplane rolls. Such complicated cross-controlling is normal when performing aerobatics.

Non-aerobatic pilots also use the controls in opposition, although much less aggressively and infrequently. Cross-controlling is how we slip the airplane on final approach when we need to lose a lot of altitude over a short distance. A slip to the left calls for right rudder to point the nose right, left aileron to put the left wing down, and pitch control as needed to maintain the target final approach airspeed.

The key to a slip is yawing the nose. Applying bank in the opposite direction is done to prevent a skidding turn so the airplane will track straight. With the nose yawed, the relative wind hits the fuselage. This creates a lot of drag, which leads to the desired result--a high sink rate.

Slips call for strict attention to airspeed since the usual final approach cues we rely on, such as the position of the nose relative to the runway, are absent. The high drag configuration can quickly bleed off airspeed if we're not careful.

For the most part, slips are something we occasionally practice but rarely perform in everyday flying. We're taught to set up each landing with a stabilized, standard-glidepath final approach. If we have to resort to slipping it means we're too high, and that's not normal. Plus, the steep descent angle and wing-down, skewed-nose configuration make a slip uncomfortable for passengers.

The cross-control maneuver that we perform with greater frequency than a slip is a crosswind landing. One of the most interesting maneuvers that any pilot--Cessna 152 or Boeing 767--does in nonaerobatic flying, a crosswind landing is true seat-of-the-pants stuff. Effective crosswind technique calls on good eye-hand coordination, quick reflexes, and a sensitive feel for what the wind is doing to the airplane and the control inputs needed to counteract that wind and land straight ahead.

But before making a crosswind landing we have to fly the final approach, and that is where basic differences in crosswind technique first show up. One method is to fly the approach in a crab. Simply let the airplane do what it wants, which is to maintain directional stability by aligning its longitudinal axis with the relative wind. In other words, the airplane will naturally weathervane into the crosswind.

If the wind is blowing right to left, for example, the nose of the airplane will tend to swing to the right, into the wind. At that point the pilot need only apply minor control inputs to keep the airplane tracking along the extended runway centerline.

The advantage of the crab method is that it is the easiest in terms of control inputs--no cross-controlling required. It's also comfortable for passengers since there is no slipping, skidding, or banking involved on final approach. The disadvantage is that the pilot must quickly and decisively transition from coordinating the controls to cross-controlling just before touching down in order to prevent landing in a crab.

The second method of flying a crosswind approach is to slip the airplane on final. With that same right-to-left wind trying to blow the airplane left of the extended centerline, put the right wing down to counteract the wind but use left rudder as necessary to keep the nose of the airplane pointed toward the runway. Vary the bank angle and opposite rudder as needed to maintain the ground track, and use pitch and power to control airspeed and descent rate.

The advantage of the slip method is that it gives the pilot a good sight picture of the runway, and plenty of advance warning on how to configure the controls for the given crosswind. Since you're already configured for the slip, there's no last-minute transition from crabbing to slipping. For that reason many instructors initially teach primary students to slip the airplane on a crosswind approach. When the student demonstrates a good command of the airplane in those conditions, the crabbing approach is introduced.

Regardless of how the approach is flown, the landing must be executed to minimize any sideways movement on touchdown. Sideways movement is hard on the landing gear, and it makes steering difficult.

Some things to consider regarding crosswind landings:

Directional stability is provided by the vertical fin (crabbing), while directional control is provided by the rudder (slipping).

The slower the airspeed, the less effective the rudder, so a bit of extra speed helps on crosswind landings. So does a bit of power, which increases airflow over the rudder, aiding its effectiveness.

No need to use full flaps on a crosswind landing unless absolutely necessary in a short-field situation. Partial flaps make for a slightly higher touchdown speed and thus better control authority. Besides, the wind will make for a slower and safer groundspeed.

A high angle of attack on approach and landing reduces directional stability and control because the fuselage blocks more airflow over the vertical fin and rudder. Again, a little extra airspeed helps.

Avoid short and narrow runways if you have to make a difficult crosswind landing. If the outcome is ever in doubt, abort the approach and choose another runway or another airport.

Mark Twombly is a writer and editor who has been flying since 1968. He is a commercial pilot with instrument and multiengine ratings and co-owner of a Piper Aztec.