By Dave Scott
As featured on page 31 in the April 2013 issue of Model Aviation
As featured with bonus interactive content in the April 2013 app
It has long been said that the key to a good landing is a good approach to the runway, in other words, one that requires few corrections. Landing is not hard when the pilot can get the airplane to the runway without having to make many corrections.
Approaching the runway without having to make a number of corrections hinges on coming out of the final turn aligned with the runway. Consistently coming out of the final turn already lined up with the runway requires that you keep your turns consistent and start them in the right spot. In short, a successful landing is accomplished through a singular focus on the setup to landing.
Good Landings Are No Accident
If you have ever watched a proficient pilot land, you probably noticed how easily he or she made it look. One reason is that proficient pilots tend to use a 180° turn to set up their landings because—compared to two 90° turns—a 180° turn requires fewer inputs and takes up less space, thereby making it easier to see and to position, especially in a crosswind.
The first step to achieving great landings is learning to perform consistent turns. Second, the final turn must be kept mostly level to avoid the anxiety and excess speed that tends to build up during a descending turn (Figure 1).
After you’ve mastered consistent turn inputs and level turns, you can start figuring out where to place your turn to consistently come out of it aligned with the runway.
Ground Targets: The Six Ps
There is an old saying, “Prudent prior planning prevents poor performance.”
Proficient pilots don’t strive to make good adjustments to come out of the final turn aligned with the runway. Proficient pilots anticipate where to start the turn so that few, if any, adjustments are needed altogether. Half of the battle is already won by locating a good target area from which to start the final turn and to come out on the centerline without having to make many adjustments.
After determining the direction in which you will be landing, walk out to the centerline of your runway and identify a ground reference on the horizon in line with the centerline. Estimate where you think you should start the final turn to come out near the centerline reference, and choose a ground reference “target” (tree, hill, etc.) to mark that turning point (Figure 2).
If there’s a crosswind, consider the effect that the wind will have on the turn and adjust the target (where you start the turn from) accordingly. Turning with a crosswind will result in a wider turn, and therefore you’ll need to widen your target (Figure 3). How much will depend on the strength of the crosswind.
Turning into (against) a crosswind will tighten the turn, so you’ll need to choose a target slightly closer to the centerline. Plan to initiate the turn when the airplane intersects your line of sight with the target, and if the turn doesn’t come out exactly over the centerline reference, adjust your target accordingly (Figure 4).
Finding good targets will greatly reduce the number of corrections needed to align with the runway, and afford you the opportunity to start thinking about the proper time to idle the engine and land. Of course, to realize the benefits of using “targets,” your turns must all be similar, which is the result of consistent control inputs.
Staying Ahead of the Wind
Although wind is often blamed for causing deviations, the principle effect of wind is helping to exaggerate the deviations and mistakes that pilots can otherwise get away with in calmer conditions.
When a crosswind exists, inexperienced pilots often make the mistake of completing the final turn when the fuselage points at the runway and then try to input a crab into the wind in response to seeing the airplane get blown off of the centerline. The result is a much more challenging approach.
The correct method is to anticipate the crosswind and overshoot or undershoot the turn slightly so that the required crab angle into the wind is already in place (Figure 5). How much will depend on the strength of the crosswind.
Even the best RC pilots can only approximate the airplane’s position above the ground at a distance, and yet they consistently end up landing on the runway centerline. That’s because proficient pilots perceive how far the runway centerline is from where they are standing and then fly the airplane to that point in front of them. Rather than making hit-or-miss estimates of where the airplane is above the ground, proficient pilots keep track of where the airplane is heading in reference to themselves (Figure 6).
In most flying environments, the runway centerline is approximately 75 feet in front of where the pilot stands. The objective is to maintain an approach that will bring the airplane 75 feet in front of you.
Compare this approach with how a person lands on the runway when flying a simulator. Because the runway does not come into view until the last moment, the pilot needs to guide the airplane nearly at his or her virtual position, remembering that the runway was directly in front of his or her virtual feet when taking off. As a result, the airplane is always close to the runway, and the tiny corrections to perfect the centerline when it comes into view are barely noticeable (Figure 7).
Controlling the Touchdown Location
Wind, model type, etc., all influence the angle and length of the landing-glide slope, making it difficult to judge when to idle the engine to consistently land near the front end of the runway. The solution is to reduce the throttle and begin a gradual descent before the final turn and by doing so, set up a lower approach. A lower approach will take the guesswork out of when to fully idle the engine since the airplane will not have far to go before touching down (Figure 8).
Determining the touchdown location on the runway is easier when standing near the approach end. When you see that the projected touchdown is going to be short of your position, you’ll know that you need to extend the approach (Figure 9). A projected touchdown in front of yourself will obviously be near the front of the runway, whereas you can predict a touchdown well past you and will likely overshoot the runway.
Besides not using ground targets and performing a diving final turn to lose altitude, the most common error made during landing is failing to establish a good alignment before becoming distracted with throttle and altitude, leading to an angled approach and a much more difficult landing.
On the other hand, those who hold off from thinking about the throttle until after they get aligned, end up having more time to properly manage the throttle because of a less-demanding approach, and the landing flare/touchdown will be much easier when everything leading up to it was more relaxed.
The ease of your landings will tend to reflect the quality and consistency of the turns that set them up. How close you come to the centerline will reflect how consistently you line up the airplane in front of yourself.
Keep the final turn nearly level and make sure you’re aligned with the centerline before you think about idling the engine. Not only will things seem like they’re happening slower, but don’t be surprised if landing starts becoming a lot of fun as well!
1st U.S. R/C Flight School