Crosswind Leg
Crosswind heading/course skills are required in every airport take off where there is anything other than a calm wind. If the wind is right down the runway then the wind effects on heading/course occur on the crosswind and base leg. Just as importantly, the wind speed effects occur upwind and downwind. The groundspeed of the takeoff and landing are as slow as the differences between Vso and wind velocity allows. If the upwind is not angled far enough away from the airport you are apt to have a very short and fast downwind. If the speed of the downwind is not anticipated in the turn to base the downwind may be excessively extended. Failure to correct heading in the crosswind and base legs makes the pattern a trapezoid (wrecked-angle) not a rectangle. The incorrectly flown crosswind leg can greatly reduce the separations normally allowed for 45-degree entry of arriving traffic. Draw it out and see the effect.

The 90-degree crosswind to the length of the rectangular pattern requires that the crosswind be adjusted. The crosswind leg will be affected by the wind. The groundspeed may be either fast or slower depending on the direction of the pattern. Adjustments to the leg length must be made in anticipation of the base leg requirements. The wind effect on the base leg ground speed will be opposite to that of the crosswind leg. Draw it out and see the difference the pattern direction makes. Draw wind direction and crab angle required.

Turning Downwind in a Crosswind
I believe that shallow banks are more likely to result in a skidding turn and a stall with the ball to the outside (high). This is a prelude to a spin. Better to always make 30 degree banks in the pattern and adjust where you rollout. This bank reduces the "blind" time in the turn. Pre-decide how you are going to correct for the crosswind. Put the plane where you want it on downwind to give a base leg length sufficient to allow corrections.

Skill in performing crosswind patterns is directly related to ground reference skills. The turn to the crosswind part of the pattern also requires awareness as to the wind's effect on speed and ground track. At 90 degrees the crosswind leg will be either a tailwind or a headwind. There is an illusion of speed that occurs during these turns. Rely on the indicated speed and not the perceived speed from your peripheral vision. Without conscious awareness this side vision will give the pilot a sensation of speed or lack of it while in a turn.

The downwind leg of the pattern requires that crab be held into the wind. The pattern should be maintained regardless of the wind. This applies either for takeoffs or landings. In a crosswind, the pilot must depart upwind with sufficient crab that the track of the plane will not conflict with the straight out path from a parallel runway. The turn from base to final must be flown so as not to conflict with the final approach of a parallel runway. Draw an airport and use the words as appropriate wind direction crosswind leg

>90 degree turn <90 degree turn

Rt. downwind leg
further out

Crosswind downwind crab angles
crab angle
base leg

Left downwind leg has dangerous effect if wind allows a short base leg.

Should you find that your patterns are getting tight because of wind, the cure is to do some 700' ground reference practice in the worst wind you can find. Go with an instructor if you can, solo if you must. The closer you are to the ground the better you will be able to judge the required correction. Once you have the required correction climb back to pattern altitude and fly the wind correction there. The idea is to develop the sight lines required.

Base Leg Turn with a Tailwind
The greatest hazard on such a base leg turn occurs when the wind becomes a tailwind. This increases the aircraft ground speed by the wind velocity. If the pilot has not correctly anticipated the increased ground speed with an early turn to final several problems arise. As the pilot becomes aware of overshooting the final turn to runway, he senses (peripheral vision) that he is moving much faster than usual. The approach and glide angle is much flatter than usual. To lower the speed he raises the nose, to correct the overshoot he wants to increase the rate of turn most often this is accomplished by additional rudder. Here we have the classic stall-spin entry in the downwind (tailwind) turn. Basic procedure if the wind is blowing you towards the runway on downwind would be to double your distance from the runway on your downwind. The 'home-field' pilot who flies by reference to ground objects for pattern orientation is especially exposed to the hazards of this situation.

Nearly 180 degree turn
to make crosswind
to downwind turn extended crosswind leg
wind direction

Nearly 180 degree turn
90 degree turn

Shallow left bank and nose held Right bank held to align with
Aligned with runway with bank runway and left rudder used to
reversed to right. Nose held straight keep nose straight.
with left rudder right wing low

Base to Final Turn
There are many ways to discuss and teach the hazard that can exist in this route source of the downwind turn with associated stall and spin. Some instructors go to great lengths to emphasize that this turn is the home of the fatal stall spin, that occurs along with a runway crosswind, a base tailwind, a steep turn, slow airspeeds, low altitude, optical illusions and excess bottom rudder. These all need not occur together. Any two or three will be enough for the unwary.

(1) The crosswind causes a short base leg;
(2) The tail wind on base causes optical illusion of excess speed so you raise the nose and lose airspeed;
(3) You overshoot the runway on base and make a steeper than usual turn to final;
(4) You need more turn but are already too steep so you apply rudder to bring the nose around;
(5) You are now low, slow, steep, yawing, stalling and out of options.

As an instructor I take another approach. My crosswind pattern practice is designed so that we practice just as many left patterns as right patterns. My preflight consists of pattern drawings and pattern walk-through that emphasize the crab angles needed to expand the distance from the runway when the downwind crosswind is blowing the aircraft into the runway. By staying well away from the runway where the crosswind will be a tailwind after our base turn we avoid the short base and the entire visual trauma caused thereby. Rather than teaching the stall recognition of this situation, I place the emphasis upon avoidance of the situation all together. The danger lies in flying the incorrect pattern in the first place.

Right Patterns
As mentioned above, the best and only preventative for getting into a situation where the base leg is too short, is for the pilot to have corrected for the crosswind on the downwind leg so as to fly a wider pattern that will give a longer base leg. This is most easily accomplished in left patterns because the runway is easier to see. The potential problem worsens in right patterns. The pilot is apt have difficulty in seeing the runway. Several dips of the wing to bring the runway into view will cause the plane to gradually move closer to the runway. This can drastically shorten the base leg and lead to a stall-spin situation. If a crosswind is moving you closer to the runway, get much further out (away from the runway) than seems appropriate and you should be about right. In this situation further away from the runway is much safer.

Tailwind Final
The turn into a following tailwind raises the ground speed. The pilot who reacts to this ground speed and not the indicated speed is likely to increase backpressure on the yoke to lower the speed. A no! no! You must understand the relationships between indicated airspeed, ground speed and relative wind. In a downwind landing your approach will be flatter, faster (ground speed) and higher. The main difference between a headwind landing and a tailwind (downwind) landing is the angle of the approach and the ground speed at touchdown. Do not increase airspeed downwind. A 10 knot tailwind on final will double your required landing distance.

The downwind rollout distance difference from a no-wind landing can be figured by finding the "square of the quotient of the actual touchdown speed divided by the normal touchdown speed" . If you normally touchdown at 40 kts and are landing with a 10 kt tailwind you will first divide the normal speed 40 + 10 = 50 by 40 = 1.25 x 1.25 (squared) = 1.56 which means that you will require 56% more landing distance with a 10 kt tailwind.  This only works if you make the same original touch-down point.  Double the distance is more likely.

Runway shallow tailwind approach diagram

A tailwind will increase the groundspeed and make the approach shallow as diagramed. The amount of tailwind varies with the relative angle of the wind.

--Add to required POH no-wind distance how far it takes to accelerate to wind speed.
--You will have a higher ground speed than normal to achieve liftoff. Fly the indicated airspeed.
--Landings require 20-percent more distance for every five knots of tailwind.
--Takeoffs require double POH distance for every 10 knots of tailwind.
--Tailwinds cause pre-mature rotation because of excess groundspeed illusion.
--Use your POH.

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