You know that the plane must be headed straight down the runway when it lands, and in normal landings it was just a matter of keeping the nose straight and the wings level. It’s a different proposition if there is a crosswind.
If the nose is kept straight and wings level on final, the plane may drift completely away from the runway
Figure 13-31. The rectangular course as applied to the airport traffic pattern.
13-20 Part Two / Presolo before you have a chance to land. Or, at best, it will
land drifting across the runway and put heavy stresses on the landing gear.
The plane will tend to ground loop because not only are the forces of the impact at work, but the plane wants to weathercock as well (Figure 13-32).
Crab Method of Correction
One way to correct for drift is to set up a crab on the final approach, then just before the plane touches, skid it straight with the runway using the rudder. True, the crab will compensate for drift, but it requires no small amount of judgment to know when to straighten the plane. You’ve had the experience during normal land- ings of thinking you’re about to touch down and then a thermal or ground effect holds the plane up for a good distance down the runway. The same thing can happen in a crab approach. You may straighten out the plane. It starts drifting again and there you sit — too little time to set another crab — so the plane lands drifting. For the next few seconds you’re as busy as a one-eyed cat watching two mouse holes.
Another common error is not straightening the plane soon enough and landing while still in a crab.
This doesn’t do the landing gear any good either. It’s best, then, that the crab method be avoided at this point of experience.
Wing-Down Method
The simplest way for the student to make a crosswind landing is by the wing-down or slip correction method.
This is accomplished by lowering the upwind wing and holding the opposite or downwind rudder. When the plane is banked, it wants to turn. The opposite rudder stops any turn and causes the plane to slip.
The procedure is this: As you roll out on final approach, lower the upwind wing the amount needed to correct for drift and apply opposite rudder to stop
any turn. Watch for any signs of over- or undercorrect- ing and adjust the bank and opposite rudder accord- ingly. The lower the wing, the more drift correction is being applied and the more opposite rudder is needed (Figure 13-33).
On gusty days you may be continually varying the bank as the crosswind’s velocity changes.
Continue to hold the wing down as necessary throughout the landing. There’s no need to try to raise the wing at the last second. As the plane slows during the landing process, more aileron and rudder deflec- tion is needed because (1) the controls are less effective as the speed lowers, and (2) the actual bank should be steeper, since the ratio of wind speed to your speed is increasing (more correction is needed). For example, if you are approaching at 100 K, a 10-K crosswind means a fairly minor correction. But by the time the airplane touches down at 50 K, the 10 K of wind rep- resents a high percentage of your speed. Of course, if your plane’s normal stalling speed is 50 K, you have no business approaching at a speed as excessive as 100 K. But it makes a good example. Land on the one main wheel and the tailwheel. The other main wheel will touch immediately after. After you are on the ground, the controls are used in the same way as for the cross- wind takeoff — ailerons into the wind and opposite rudder as needed to keep the plane straight. Land the tricycle-gear plane on the one main wheel also. Ease the nosewheel down immediately after the other main wheel touches for effective ground steering in the crosswind. This method is so simple and effective that it is the most popular way of correcting for drift during the approach and landing.
Some airplanes have nosewheels that “fall free”
from the steering mechanism so that when there is no weight on the wheel (anytime it’s off the ground), the wheel will be free to track along the ground path when
Figure 13-32. Hoping that you’ll touch down before the wind drifts you off the runway is no way to take care of a crosswind.
A ground loop could result.
Chapter 13 / Takeoffs and Landings 13-21
Figure 13-33. A crosswind approach as seen from behind the airplane and from the cockpit. The slipping resultant (R) compensates for the crosswind component. If you had time to check it, the needle in the turn and slip indicator would show no turn, but the ball would show a slip.
it touches. In other words, in the wing-down crosswind approach the deflection of the rudder does not have the nosewheel “cocked” at touchdown. Other airplanes have a continual direct connection from rudder to nose- wheel so that in a left crosswind (left aileron, right rud- der), the airplane could have a tendency to veer to the right as the cocked nosewheel touches. Your instruc- tor will discuss the best crosswind procedure for your airplane.
As you are slipping, a slightly steeper glide results, but this is of no great significance.
The only time that slipping is used to correct for a crosswind is on the final approach and landing. After shooting crosswind landings some students climb with a wing down after takeoff. All this does is cut down the rate of climb.
Probable Errors
1. Letting the plane turn when the wing is lowered.
2. Not recognizing drift.
3. Mechanical corrections — putting the wing down at a certain angle and not changing it, even though the crosswind varies.
4. Getting so wrapped up in the drift correction that the landing is forgotten.
If you bounce during a crosswind landing, remem- ber that the plane will start drifting. Lower the wing and use opposite rudder as you reland the plane.
The crosswind landing technique is a form of side- slip. The sideslip, you remember, is a slip where the nose is pointed at an object (say, for instance, the run- way) and the plane slips to one side — toward the low- ered wing. In this case, the plane’s movement to the side is counteracted by the wind. If you overcorrected
for drift or if there was no wind, the sideslip idea would be evident. In strong winds the two methods may be combined (crab and wing-down).
Crab Approach and Wing-Down Landing
You may like this idea better than the long slipping approach, which can be uncomfortable to both pilot and passengers.
As shown in Figure 13-34, this technique is to set up the proper crab angle (it will have to change as the wind changes on the approach) and maintain a straight path over the ground by this method until the point of round-out is reached. The airplane is then lined up with the runway, and the wing is lowered into the wind (and opposite rudder is used) as necessary to correct for drift as the landing is completed. It takes time getting used to making the transition, but with practice you’ll prob- ably find this method more to your liking than the long wing-down final.
You may have a problem getting the idea of the wing-down crosswind correction because in most cases you’ll have this condition set up for only a few sec- onds during the very last of the final approach and the landing. Some instructors, for a training condition, will set up the landing approach 5 or 6 miles out on final, controlling the power themselves, and let the student see that the sideslip does work and, because of vary- ing crosswinds, the correction may need to be changed throughout the approach. This technique is used to give the student more time to get used to the cross-control effect. After the idea is firmed up, the instructor will usually go back to the crab approach and wing-down landing (or you may prefer the wing-down method for all of the final leg).
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to idle) is not matched by a 30-second final leg. Because of the headwind on final, depending on its strength, the final leg might be 1 minute or more (as an example), with that extra time of retarding effects resulting in not making the runway unless power is used.
With experience you will be able to judge a proper distance from the runway (called “abeam distance”) for these approaches, but some instructors use aids such as masking tape on the wing (low-wing airplane) or on the strut (Figure 13-37).
If there is a crosswind as shown in Figure 13-31, you will have to make corrections for wind on the crosswind, downwind, and final legs as well as that expected on base.
The first turn, onto base, should be (as mentioned earlier in the chapter) fairly steep (up to 30° bank), particularly in a high-wing airplane. The 90° (plus) of turn should be completed without delay so that you will arrive at the base key position with the wings level and a good view of the runway to check for needed correc- tions. On base always look to the right (in a left-hand pattern) to check for airplanes that might be making a long straight-in approach.
A problem instructors find on the base leg is that students often stare straight ahead over the nose, and not look at the runway until they think they are ready to turn onto final. This habit often leads to a late turn and flying past the runway center-line extension (Figure 13-38). This could lead to the dangerous situation of
“cheating” on the turn with a cross-control stall result- ing (see Chapter 14).
So it’s better in most cases to make the turn onto the base leg with a fairly steep bank (up to 30°) and the turn onto final with a more shallow one (20° or less).
See Figure 13-39.
Figure 13-40 shows the results of that too-shallow bank onto base, as seen from the cockpit.