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Vintage Instructor THE

BY Steve Krog, CFI

Wind, takeoff, and traffic patterns Part 1 How do you fly the traffic pattern, especially if you are going to do two or three takeoffs and landings? “Never much thought about it,” is the reply most often offered when I’m conducting a flight review. “It sort of comes natural,” they add. “Is that why we were about one-quarter mile south of the runway centerline during the climb-out,” I offer? “Geez, I never realized I was doing that,” the pilot responds, “Why are you making such a big deal out of it?” My reply is, “To prevent a midair collision, and so that you can make a good landing.” “What does my climb-out have to do with my landing?” Everything! Precision in the traffic pattern usually leads to a good landing.

Takeoff and Climb-out NOTE: Assume in the following example that we are experiencing a 45-degree crosswind from right to left at 12-15 mph. After completing the pretakeoff checklist but before every takeoff, what do you do? Align the airplane with the centerline and push the throttle to the stop? Or do you take a few seconds and think about the takeoff? Do you ever ask yourself the “What if” questions? What if the engine sputters and quits before liftoff? Just after liftoff? Do you remember to take a quick peek at the engine gauges as the power is added? What is the surface wind doing just before adding power? If these questions are answered honestly, most would agree that the airplane, engine, and pilot inputs are oftentimes taken for granted. Maybe we could and should all pay a bit more attention and run through the “What if” questions before each takeoff. Let’s take a look at how the airplane responds in a crosswind takeoff and the actions, or lack thereof, of the person at the flight controls. Many of us general aviation pleasure-flying pilots will glance at the windsock as we taxi away from the hangar and make our way to the preferred runway. After determining which direction we’ve selected for the takeoff, we never again look at the windsock. Rather, we just assume the wind won’t change before we get into the air. The surface wind can be quite variable in any given day, particularly if it is less than 15 knots. Have you ever

32 JUNE 2012

found yourself adding power, beginning the takeoff roll, and then found that the airplane decided to take you on a cross-country tour through the tall grass on either side of the runway? It catches you by surprise as you apply corrective control inputs, but the question comes to mind, “What was that, and what did I do wrong? The wind was right down the runway when I last looked (7-10 minutes ago).” When working with students, I insist that they take one last look at the windsock before applying power. Beginning with the takeoff roll, the control stick or yoke should be all the way back in your lap and turned or pushed near fully to the stop in the direction from which the wind is coming. A crosswind from the right requires the stick to be pushed or turned to the right. The right aileron is deflected to the up position, preventing the right wing from generating more lift than the left. With the stick or yoke in the full back or aft position, the prop blast and the relative wind cause a downward load on the tail, keeping the steerable tail wheel firmly planted on the ground as power is applied. Directional control for the first four of five seconds of the takeoff roll is maintained by the tail wheel and proper rudder pedal application. Generally, several soft taps on the right rudder are needed in a calm or light head wind situation. But in this particular situation one may need to tap the left rudder to offset the crosswind that is attempting to push the tail to the left and the nose to the right. As groundspeed increases, pressure on the elevator can be felt in the control stick. At this point, gently move the stick slightly forward, lifting the tail about a foot off the ground. A mistake commonly made at this point is raising the tail too high, creating either a neutral or negative angle of attack. This tail-high attitude significantly extends the length of the takeoff roll. Simultaneously, light rudder pedal taps will be needed to maintain straight-line directional control. If the crosswind is strong, left rudder will be needed, but if it is light, right rudder will be required to offset engine torque and propeller P-factor. We began the takeoff roll with the right aileron fully deflected upward. With increasing groundspeed, the controls become more effective and less aileron deflection is needed to offset the crosswind. Just as the airplane leaves the ground the control stick should be rotated to a neutral


position, causing the aileron to assume a neutral position as well. Oftentimes a pilot will continue holding aileron deflection during the liftoff, causing the wing to dip in the direction of the wind. Simultaneously, some pilots will then add and hold left rudder causing a slip/skid configuration. Correct this by glancing at the space between the bottom side of each wing and the horizon line. In a lowwing airplane, look at and balance the space between the top of the wing and the horizon. Level the wings and take your foot off the left rudder pedal. Once airborne, even in a light crosswind, I like to climb to about 15-20 feet, then level off and neutralize the rudder and ailerons if you’re still holding the windward wing down. Depending on the crosswind velocity, the airplane will “weather vane,” basically establishing its own crab angle. When the crab angle stabilizes, resume the normal climb-out attitude while maintaining the crab angle. Don’t forget to apply light but constant right rudder during the climb to offset torque and P-factor. This will allow you to climb on a straight line off the end of the runway. Continue the climb until reaching at least 500 feet above ground level (AGL), and then lower the nose to a level attitude. Depending upon the level of activity in the flight pattern and airport traffic area, you may want to vary your climb attitude and airspeed for safety. Traffic volume may dictate a more gradual climb angle so that you can more easily see over and around the nose and spot any potential traffic conflicts. A designated pilot examiner (DPE) friend, for whom I have a great deal of respect, recommends making gradual S-turns passing left and right through the imaginary extended centerline during the climb. This will allow seeing whatever is in front of the airplane (i.e., to better see other traffic). This is an especially good practice when flying an airplane like the J-3 Cub, as the nose blocks all forward visibility when in a normal 60-mph climb attitude. Just because your airplane will climb out in a steep attitude, there is no need to demonstrate this feature when departing a fly-in. Wait until you are clear of the airport traffic area, then play. It may someday save a near miss or even worse.

Head wind or Tail wind on Crosswind Leg After lowering the nose and clearing the area for other traffic in or approaching the traffic pattern, establish a shallow-bank climbing turn to the left (for left-hand traffic patterns). In a light or no-wind condition this turn would be approximately 90 degrees, so that you are perpendicular to the departing runway but flying away from that runway. In this example we are turning from a right-quartering head wind to a right-quartering tail wind. If this is not taken into consideration, the crosswind leg will not only increase your groundspeed, but the wind will also push the airplane leftward toward the runway, tightening the traffic pattern track. To correct this situation, roll out of the

turn about 10 degrees early to establish a slight crab angle to the right, offsetting the wind’s push. The increased groundspeed will necessitate initiating the turn to downwind a bit more quickly than you may have anticipated. The crosswind leg of the traffic pattern is the leg that is most often abused by students and certificated pilots alike, based on my experience. Frequently, neither the wind direction nor the velocity is taken into account. In turn, a sloppy crosswind leg leads to an equally sloppy downwind leg, which then leads to a bad base leg. I’ve mentioned this before, but I’ll state it again. If I’m flying with an individual who is flying a sloppy pattern, I’ll challenge that person to a contest. I will predict, while on downwind leg, if the landing will be good or not. A student will almost always accept the challenge. I’ll write the letter “G” or “B” on my hand—“G” for a good landing and “B” for a less than good landing. I can truthfully say that I’m correct well more than 90 percent of the time. The more things are done properly and correctly while flying the traffic pattern, the fewer things have to be fixed on either the base leg or final approach. The fewer things to fix, the better the landing. Note: In the next issue I’ll explain the downwind, base, and final legs of the traffic pattern and what I look for to help make a better, more comfortable, safer, smoother, and uneventful landing.

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2012-06-Wind-Takeoff-and-Traffic-Patterns-Part-1