by Harold Green, CFII
One of the many advantages pilots in the Midwest enjoy is an abundance of wind of various strengths and directions not enjoyed in other parts of the country. High wind conditions are a source of both concern and joy for pilots. As the learning process begins, the thought of high wind conditions, particularly crosswinds, strike fear into the heart of almost all pilots. Then, once crosswind techniques are mastered, there are few things in flying that produce the ego satisfaction like a “greaser” landing in those conditions. The transition from concern to satisfaction is one of knowledge, experience and perhaps most importantly, self-confidence. Hopefully this article will shed some light on the subject.
No cross/high wind discussion can be complete without considering ground operations. Unlike the flight environment, wind on the ground can impact the airplane from any direction and that relative direction changes, both as we change our direction on the ground and as a result of wind patterns created by ground obstacles.
The first consideration is to keep the airplane from tipping over as a result of the wind. Whereas in the air the plane just moves with the wind, on the ground an airplanes’ landing gear provides a pivot point about which the airplane can react. This includes the possibility of flipping over. After all, a tricycle gear airplane is nothing more than a three-legged stool and will flip diagonally forward nicely using the nose gear and one main as a pivot point if the wind gets under a wing or the horizontal stabilizer. A tail-dragger will flip also, but will tend to do so straight ahead since its pivot point is the main gear rather than the nose gear and one main.
Our principal goal in ground operations is to make sure the wind does not have a chance to flip the airplane. Therefore, it is critical to keep the wind from raising either a wing or the horizontal stabilizer. Just as in flight, we use the control surfaces to achieve this goal. (After all, we have nothing else to work with.)
The best way to accomplish this is to make sure that the upwind wing and the tail is held to the ground. If the wind gets under a wing, over we go and that is considered bad form. The best way to accomplish this is to remember the mantra; “Roll away from a tailwind and into a headwind.” That keeps the upwind wing glued to the ground because if the wind is from behind, it will push the upwind aileron down and hence the wind holds the wing onto the ground, and if from in front, the upwind wing will be told to bank into the wind. The elevator should be set to pitch the airplane down because with a tailwind, it will push the tail down, and as the tail goes down, both wings will tilt up and present a larger surface for the wind to hold the airplane onto the ground.
Taxiing in a high wind can be an attention-getting experience. Since the airplane’s landing gear provides a pivot point, the wind will try to turn the airplane into a weather vane. This can be a decided challenge, particularly if your sky steed happens to employ a castering nose-wheel, or you are driving a tail-dragger. In these cases you will need to pay attention to differential braking. Of course strong gusts will get your attention no matter what you’re driving.
As a cautionary note, remain aware of terrain and obstruction between you and the wind. If you are taxiing close to obstructions, expect turbulence and hence a change in wind direction as you pass by them. Don’t be caught by surprise.
It is not uncommon for a row of hangars to be close to a taxiway. If those hangars are between you and the wind, you can expect a venturi effect as you pass between buildings. This will result in a distinct and rapid attempt to turn into the wind the stronger the wind, and the closer the building, the stronger the attempt to turn. Gusts only add to the fun.
Effective and quick use of controls and brakes are in order here. Taxiing close to a building can result in unanticipated winds as the airflow curls around a corner of the building.
Since the relative wind changes as the airplane changes directions as it taxis, it is necessary to remain oriented with respect to wind direction over the airplane. Of course, blowing grass or snow, a windsock, etc., work. However these can come and go as we move about the airport.
A very effective method is to set the heading bug on the directional gyro to the wind direction. Then, if the heading bug is behind the 90-degree point, you bank away from it, and if ahead, you bank into it. If it is at 90 degrees, ailerons are neutral.
Throughout all of this it can be hard for beginners to realize that there is only one position for the controls in high wind ground operations. With respect to ailerons, there is only one position: To the STOPS! That is because we aren’t after fine control…we are after solid control, and there is no way to judge the effect of them until we are in danger of losing control. Hence: All the way!
As with the ailerons, we want the elevator to help hold us on the ground. When the wind is behind us and strong, the elevator should be forward. This causes the tail to lower and brings the wings to a higher angle causing the wind to help hold the airplane to the ground.
Now, having arrived at the takeoff point, completed the pre-takeoff check and briefed our passengers and received takeoff clearance, if at a controlled airport, it is time to do the deed.
The first step is to turn onto the runway so we are on the upwind side of the centerline so we can take advantage of the crown in the runway to help hold us onto the ground.
Consider what is about to happen: As the airplane accelerates, it is going from normal weight applied to the landing gear to zero. That means that the wind can easily move it sideways, scrubbing tires and even tipping us – a situation we definitely don’t want. With a crosswind we must hold the plane on the runway without letting it skid until it reaches flying speed. Then, holding FULL aileron INTO the wind, and full DOWN elevator, we smoothly add power – full power – and focus on tracking straight down the runway.
In a tricycle gear airplane, forward elevator ensures that the nose wheel stays glued to the runway. However, be prepared to modify the forward pressure to avoid wheel-barrowing by running on the nose wheel with the mains off the ground. This is of far more concern in a low-wing than a high-wing airplane. The pressure should be sufficient to hold the airplane on the runway.
In a tailwheel airplane, life is actually easier because it can’t wheelbarrow and excessive forward elevator will actually glue the airplane to the runway more firmly. The worst impact is to increase the takeoff run. No matter the airplane type, as the speed increases, the aileron can be neutralized – just keep the upwind wing from lifting prematurely.
We know when flying speed has been reached because the airplane is arguing with us. It doesn’t want to stay on the runway requiring our attention to keep it there. Once at flying speed the ailerons should be at neutral and the airplane can be flicked off the ground. That means we quickly apply back-pressure sufficient to make the airplane fly, but insufficient to produce a large pitch up.
Usually this is just a flick of the wrist, which quickly gets us airborne without skidding sideways. Once airborne the airplane is in its natural environment where crosswinds don’t matter and we just turn into the wind to track down the runway until we are ready to turn. Job done!
Now it is time to get set for the landing. Not surprisingly the landing begins in the pattern, be it a controlled or non-controlled airport. By the time we select our runway, or the tower does it for us, we know from which direction the surface wind is coming from. Therefore, given a choice, we will select a runway, which provides the least crosswind. Additionally, sometimes the wind is virtually at 90 degrees to a runway and this gives us an additional choice. Knowing that we still have too many accidents when people overshoot the turn from base to final, we will choose a runway, which provides a headwind on base. If we can’t do that and we have a tailwind on base leg, then we will plan on turning early to prevent overshooting the final leg.
Hopefully when we complete our turn to final, we will be at the appropriate altitude and lined up with the runway centerline. If not, we move ourselves so we are. It is also advisable to place ourselves just to the upwind side of the centerline so as to take advantage of the runway crown to help us remain glued to the runway after landing.
To do a thorough job of discussing the landing itself, we need to consider a multitude of factors including technique, flaps, ground effect and others, so we will leave that for the next article. Then we will consider the “crab” and “kick vs. the slip” method and the effect of “high vs. low-wing” operations in high crosswind landings.
EDITOR’S NOTE: Harold Green is a Certified Instrument Flight Instructor at Morey Airplane Company in Middleton, Wisconsin (C29). Email questions or comments to: firstname.lastname@example.org or call 608-836-1711 (www.MoreyAirport.com)