Touchdown!

When rubber meets runway

September 1, 2003

It's like a ballet of hands, feet, and head that all pilots perform on every flight. Its procedures aren't on any checklist. It's over in 10 to 15 seconds, but it usually takes 10 to 20 hours of flight time to learn. Once it's learned, experts say you never forget. And the procedure is so important that a pilot's skill and reputation is judged by this seconds-long dance.

Let's call it the magic moment, or the moment of truth. A complex, precise confluence of physical, mental, and psychomotor variables comes together to make that perfect landing, and the wheels smoothly meet the runway.

It's often a time of rapid-fire control inputs, depending on your airspeed, the surface wind, turbulence, and the airplane's configuration. But your inputs must be instinctive, and your reactions immediate. That's where practice comes in. No book can teach you how to land.

To simplify these few seconds of flight time, let's divide them into three stages: roundout, flare, and touchdown.

Roundout

This stage begins shortly after entering the altitude where ground effect kicks in — about wingspan-high. The idea is to "break" the glide profile you've been maintaining all the way down short final. Now it's time to slow your descent rate in preparation for landing. After all, you wouldn't want to carry a 500- to 700-fpm descent rate right to the tarmac. That works for naval aviators who have to make sure their airplanes get glued to the carrier deck in the shortest space possible, but for those of us flying less sturdy general aviation airplanes, a "landing" like that would probably damage the airframe.

So the roundout is where back-pressure is first applied to the control yoke or stick. This is a subtle move — too much back-pressure too soon, and the airplane will balloon. Up to this point you've been maintaining the target airspeed for final approach. But by arresting the descent, some of that airspeed will bleed away. Which is good, because flying your final approach reference speed all the way to the runway can have some unpleasant effects. Like ballooning, or bouncing, or porpoising, or wheelbarrowing, or using too much runway to stop the airplane.

The roundout marks the time when you begin to devote your full attention to the runway threshold.

The slower you fly, and the closer you get to the runway, the less accurate your airspeed indicator will be, so you have to rely on your feel for the airplane in slow flight to estimate your margin from the stall. If a crosswind or turbulence requires any control inputs, you'll be looking at your runway alignment and your attitude with reference to the surface for input cues. In short, the roundout is where you start to make the airplane slow down, line it up with the runway, slow its descent, and watch the threshold for signals that corrections are needed. You may have been approaching by the numbers, but now you're flying by the seat of your pants.

Flare

This stage begins just a few feet — say, 10 feet or so — from the runway. Using aft stick pressure, further reduce the descent rate. Then progressively increase the aft stick pressure. This bleeds off airspeed, increases angle of attack to stalling values, and keeps the airplane's nose well off the runway. In the flare, many instructors tell their students to try to "prevent" the airplane from landing, to hold it off the runway, to achieve the desired result.

Of course, no two landings are alike, and neither are the conditions. Strong crosswinds, for example, may keep you busy lowering a wing into the wind — at the same time you're applying opposite rudder to keep the airplane's longitudinal axis lined up with the runway centerline. And all through this you have to concentrate on the flare.

Touchdown

If things go well, the actual planting of rubber could be anticlimactic. The airplane has been slowed to the point where the stall horn is blowing, the nose is in the air, aft stick pressure is maintained until touchdown, and ailerons and rudder are used as necessary to stop any drift or weathervaning from crosswinds. Fast, yet subtle control inputs may be the order of the moment as the airplane is prepared for the chirp of mains on runway — or even better, a noiseless, undetectable roll-on.

After touching down, maintain continued aft stick pressure to spare the nosewheel and hasten the transfer of weight from wings to wheels. As airspeed drops off and the elevators lose effectiveness, the nose will drop on its own. Then you can apply brakes and bring the airplane to a stop, using rudder for ground steering.

Sound easy? We all know it isn't. Knowing just when to apply back-pressure, just when to kick out rudder inputs, or just when to expect the wheels to roll on comes with experience — and practice. There's nothing mechanical or rote about learning how to pull off that elusive perfect landing. It's easy, yet perfectly correct, to say that a good landing is the culmination of a steady, well-managed decrease in both power and airspeed, from final approach to touchdown — all the while being ready for a go-around. But to be in the left seat and doing one? That's the true test, when you need a strong psychomotor memory of a grab bag of landing skill sets. That, and a little bit of luck won't hurt either!


E-mail the author at tom.horne@aopa.org.


Avoiding the Bunny Hop

Tailwheel pilots have more fun

BY ALTON K. MARSH

There's little difference during final approach between a nosewheel airplane and one with a tailwheel. But all that changes during the roundout and flare.

While still on downwind the tailwheel pilot has already thought about the type of landing to be made. The nosewheel pilot is going to make a "wheel" landing every time, but the tailwheel pilot can make either a wheel landing or a three-point, touching the mains and the tailwheel at the same time. Both share a secret: Airspeed control to within a knot or two of the desired speed on final is critical. And it is far more important that the tailwheel aircraft touch down with no drift: With the center of gravity behind the main wheels, the main wheels serve as a pivot point for any sideways motion. The airplane would love to go down the runway backward, and landing with sideways drift enables tailwheel aircraft to swap ends.

Both landings start with a game called "How low can you go?" Like a limbo contest, the pilot getting the airplane lowest before starting a transition to either landing is going to win, or in this case, make the best landing. Of the two, the wheel landing is the more difficult, and is done to provide better control in turbulence or crosswinds. How low is low? Delaware flight instructor Tony Markl suggests somewhere between your feet and your knees. Unlike the roundout in a nosewheel aircraft, there is little roundout at all during a wheel landing in a tailwheel aircraft, and the nose remains in nearly the same attitude as during the glide. After the airplane is level above the runway, a new game starts, one with a goal of cutting the descent rate to zero just as the wheels touch. That's the more difficult game.

Somehow, Markl notes, you've got to keep your forward speed but reduce the descent. Yet, too much speed will bounce the landing. What to do? Some pilots add a little power, or at least don't remove any. Markl suggests you stair-step your way down from knee height. By that he means move the stick or wheel forward an inch and right back to where it was, and forward and back until you have touched down.

"This technique avoids the common problem of letting the nose rise and getting bunny hops," Markl said. A rising nose during a wheel landing is a sure sign of trouble to come. "Bunny hop means we land in a two-and-a-half-point attitude with too much speed, and touch the mains, and touch the tail, and touch the mains, and so on," he added. When you get into that kind of trouble — and there are no gusts or crosswinds requiring a wheel landing, and the aircraft is aligned with the centerline — convert to a three-point landing. Otherwise, a go-around is the better solution to bunny hopping, similar to what FAA manuals call porpoising.

Once the main wheels are safely on the runway, you'll need to push the stick forward. Most nosewheel pilots fear at this point that they are going to strike the prop — no small concern and one that takes practice to overcome. The FAA prefers that you hold the stick forward, increasing pressure until the tail falls of its own accord.

The three-pointer

Markl suggests the roundout from final approach to the three-point landing can begin a little higher, such as the height between your knees and chest. Still, that's pretty low, and new or rusty tailwheel pilots are reluctant to get down there. Here's a tip: Sit in the airplane on the ground and over time, memorize that sight picture. Also, that is obviously the attitude you want for a three-point touchdown. What do you suppose nosewheel pilots do on their first attempts at a three-point landing? That's right — the nose keeps coming up and up, well past the three-point attitude, and the tail hits first. Then the main wheels flop onto the runway.

Unlike the wheel landing, the three-point requires the airplane to be near a stall at touchdown. The process, as you may have guessed by now, is to maintain the glide until reaching chest height, rounding out while allowing the aircraft to settle, and holding it off a few inches above the runway until it stalls and touches down. That requires the pilot to know the landing attitude and to continuously apply back-pressure to the stick or yoke. In an ideal world, the elevator reaches its stop as the wheels glide on with the aircraft just at the stall speed.

Thomas A. Horne

Thomas A. Horne | AOPA Pilot Editor at Large, AOPA

AOPA Pilot Editor at Large Tom Horne has worked at AOPA since the early 1980s. He began flying in 1975 and has an airline transport pilot and flight instructor certificates. He’s flown everything from ultralights to Gulfstreams and ferried numerous piston airplanes across the Atlantic.