by Jeb Burnside
Many of us still have problems maintaining directional control during takeoffs and landings, especially in crosswinds. While the wind is not always our friend, it is what it is and pilots have to learn to deal with adverse winds-along with many other challenges-on their way to proficiency. Sure, a stiff crosswind can be intimidating, but it should not pose a major challenge to pilots. In fact, getting the airplane on or off the runway is rarely the problem. Instead, how we handle the bad things that can happen while the airplane is transitioning from airborne to ground-borne and back are what makes the difference between success and an insurance claim. That the basic techniques of directional control havent been perfected by all pilots should be evident to anyone who has taken a glance at the accident record.
For example, on January 8, 2003, a Cessna 172S was damaged following loss of control upon landing on Runway 18 at the Springdale (Ark.) Municipal Airport. The solo Student pilot was not injured. The 40-hour Student pilot reported, I had my wind correction in with the right wing dipped and the left rudder pushed. When I landed, I touched the right wheel down and then the left wheel. As soon as I touched the left wheel down, I [applied the brake] and ran off the left side of the runway. The aircraft veered off the runway into the grass, crossed a parallel taxiway, struck a culvert, and came to rest against a concrete ditch. Winds were from 240 degrees at nine knots.
Another 172 got bent on February 14, 2003, when it veered off Runway 8 during the takeoff roll at the Clare Municipal Airport in Clare, Mich. The Student pilot, who had a total of 38 hours of flight time, reported that she pulled the nose up too soon during takeoff. The airplane veered to the left as she tried to lower the nose. She reduced power but was unable to prevent the airplane from departing the runway and hitting a snow bank on the left side of the runway.
From these two events, its easy to conclude that these pilots failed to fly the airplane. But the point often lost in considering what it takes to fly the airplane is that it needs to be flown when its on the ground, too, sometimes all the way to the tiedown. By understanding the common tools available to us, we can do much better at maintain directional control on the runway, with and without a crosswind.
1. Control Thy Airspeed!
When considering directional control on a runway, airspeed can be a critical factor. Too much airspeed on landing and we use much more runway than necessary, burn up brakes and can wheelbarrow-put all the airplanes weight on the nosewheel-leading to loss of control. Not enough airspeed means there is insufficient air flowing over the control surfaces to ensure our inputs will have the desired effect, like using the ailerons to hold down a wing into a crosswind or using the rudder to compensate for torque. As the second example at the top of this article demonstrates, lifting off at too low an airspeed puts us in a situation where the engines torque, P-factor and the lack of air flowing over the rudder can all combine to point the airplane where we dont want it.
On arriving, insufficient airspeed can mean a hard landing after the airplane stalls above the runway. As the airplane stalls, its attitude, including its direction, can change rapidly. In a hard landing, the airplane can head for the weeds faster than you can ask, Is anything broken?
Landings and takeoffs in a stiff crosswind are sometimes improved-and made safer-when using a little extra airspeed. On takeoff, accelerating to a slightly higher liftoff speed helps counteract the downwind drift a crosswind may impose. On landing, especially when there are gusts, a few extra knots not only provides slightly crisper controls but also provides a margin of error. In both cases, too much is not a good thing. Figure on half the gust as the amount you should add to your normal liftoff and approach speeds
The rudder is, by far, the tool most critical to maintaining directional control. Too often, however, pilots concentrate on using ailerons to control the airplanes direction on the ground, just like they drive a car. It just doesnt work that way. Good directional control depends on good rudder skills.
On takeoff, you could well need full rudder input-a foot on the floor-to maintain directional control. This is especially true in a U.S.-manufactured single with a stiff breeze from the left. As the airplane accelerates, gradually relax the rudder input-youll know both when and by how much if you keep your attention focused down the runway to catch the slightest change in heading. At liftoff, youll need to coordinate the rudder with the ailerons to smoothly roll into a crab angle aimed in the direction from which the wind is blowing.
On landing, the required rudder input will be pretty much the reverse. At touchdown, youll have added enough rudder to keep the airplanes longitudinal axis aligned with the runway, especially when keeping the upwind wing lowered into the crosswind. Before the small wheel touches-whether its on the nose or the tail-rudder is the only thing keeping you on the runway. As the airplane slows, rudder effectiveness will decrease and youll be rolling too fast to use the brakes. Again, keep your attention focused far down the runway to catch heading changes-youll probably need to progressively add more rudder until the airplane slows enough to use the brakes.
Ailerons are also used in maintaining directional control. Especially in high-wing airplanes, start your takeoff roll with ailerons positioned into the wind-put the yoke or the stick against the stop in the direction from which the wind is blowing. This will help keep the upwind wing down and the planes weight on the wheels. As airspeed increases in the takeoff roll, gradually relax the aileron input. Ideally, just enough aileron input will remain at liftoff so that the airplane will smoothly roll into a crab angle against the wind, enabling a departure path on the extended centerline.
On landing, do the reverse. Youll probably have a bit of aileron into the wind at touchdown. Gradually increase that input so that full aileron into the wind is achieved at some point after the airplane stops flying and all the wheels are on the ground, but before slowing to taxi speed. This will help keep the upwind wing down and prevent a gust from lifting it. This is a required technique in high-wing airplanes when taxiing, even if the runway is perfectly aligned with the wind, and is useful in low-wingers, too.
Judicious use of the throttle can work wonders in maintaining directional control. The amount of time we take to come up to full power can dictate how much control we have early in the takeoff roll.
For example, a crosswind from the left on takeoff will tend to weathervane most single-engine airplanes built in the U.S. in that direction, since the engines rotation-clockwise when viewed from the cockpit-tends to pull it to the left at low speeds. At those low speeds, you may not have enough right rudder available to stay on the centerline.
In this case, adding only partial power early in the takeoff roll and allowing the airplane to accelerate until adequate rudder authority is obtained is the way to go. As the airspeed increases, so will rudder authority. Once airflow over the rudder is adequate, a smooth addition of full power wont mean losing control.
In conventional twins-those with the engines on the wings-differential power can be used to help stay on the centerline. Instead of bringing up both engines to full power early in the takeoff roll, consider using only partial power on the upwind engine until you have plenty of rudder authority. Of course, bringing up both engines to full power as soon as the rudder can handle the demand ensures no other problems exist.
Generally, applying power wont help maintain directional control on the landing rollout. Two exceptions come to mind, however. The first is with a taildragger: A burst of power over the rudder can miraculously salvage a near groundloop. Similarly, using a twins differential power ability can help keep things on the pavement when all else appear lost. Dont forget, however, that you eventually have to stop.
The wing flaps position can also influence directional control. When landing in a stiff crosswind, especially in a high-wing airplane, using partial flaps may be a good practice if the runway is long enough. Of course, fully extended flaps in most airplanes create a lot of drag, allowing lower speeds. Using partial-or no-flaps on landing usually means well need a few extra knots, knots that can enhance directional control. As with all things, of course, too much is not good-trying to slow and stop after a too-fast landing may compound our directional control problem.
On takeoff, you should use whatever flap setting is appropriate to the runway length and the airplanes limitations. Just remember that a gust encountered at the wrong time could shove the airplane too close to the runways edge in the case of a less-than-crisp liftoff.
Wheel brakes are used to maintain a crosswind-induced loss of directional control only as a last resort, perhaps to slow the airplane as it crunches into a runway light. On icy or wet runways, they can do more harm than good.
Using brakes to control direction can drastically lengthen the required takeoff distance and may mean not clearing the trees at the other end. On landing, premature brake application-especially differential application, as demonstrated in one of the accidents cited at the top of this article-can mean an excursion into the weeds or a snowbank. To help prevent this, stay off the brakes early in the landing.
Brakes should rarely be used to maintain directional control on the runway. When the airplanes speed is above that used to taxi, its time to transition to the flight controls and stay off the brakes. Exceptions are when attempting to stop on the runway or when intentionally groundlooping.
The Kitchen Sink
When the airplane is airborne, directional control is a matter of aileron rolls coordinated with appropriate rudder input to smoothly turn to or maintain the desired heading. On the ground, its a different matter entirely.
During normal taxi operations, some combination of power, rudder/nosewheel steering and differential braking is used to keep things headed in the right direction. During the takeoff or landing rolls, however, all of the controls may be needed to keep the pointy end pointed where you want it.
Taking off in a really stiff crosswind demands using all the controls to maintain directional control. Start by lining up on the runways centerline and only adding power after full aileron is applied into the wind and youre sure you have sufficient rudder authority. Landing is pretty much the reverse, except for using power.
Maintaining directional control when dealing with crosswinds is an important part of the battle. Using all the controls available will help keep you out of the weeds-or the snowbanks.
Also With This Article
“Taking Control Of Crosswinds”