Landing An Airplane Essentials
Folklore: If we shift our aim to the horizon during the landing flare, we will be able to judge a proper touchdown at our aimpoint.
The idea behind shifting our eyes from the runway aimpoint to the horizon is to give us the best depth perception to judge when our descent rate has been arrested. There is a truism in the art of riding motorcycles that says the bike goes where your eyes are looking. I find that putting your eyes on the horizon leads you to level off, which many pilots think is the entire goal of the landing. The problem is this: Have we stopped our descent rate an inch above the runway or 10 ft.? Or perhaps we misjudged that and would have stopped it at -10 ft. except there was pavement in the way. Attempting to end the flare right above the runway is difficult and carries a risk of landing short or long.
Most aircraft are designed to land with a descent rate that is only partially arrested. The highest I’ve seen is in the G550, which is designed to land while descending at 8 fps, which comes to 480 fpm. That is just barely short of that airplane’s normal glidepath descent rate of 600 fpm. I don’t know anyone who does that with a load of passengers on board. But if you are in the habit of landing on runways within a few hundred feet of the computed landing distance, you need to know what it takes to achieve your flight manual’s performance numbers.
I practice these “performance landings” in the simulator, just to make sure I know how. In the real world, I insist on an extra 1,000 ft. of runway over my aircraft manual’s requirements. (We’ve actually written that into our operations manual.) For these conditions, I shoot for a mere 100-fpm descent rate at touchdown. That puts me down at my aimpoint reliably and avoids long landings. This technique produces comfortable landings in all but the most stiff-legged aircraft. You won’t be getting applause from the cabin, but you won’t be having to explain any excursions beyond the paved landing surface. So your goal should be for a slight descent on touchdown. But how do you do that?
I find that raising my eyes to the end of the runway, but below the horizon, does the trick. The photo shows the flight path vector (symbology that shows the aircraft’s trajectory) slightly below the end of the runway because I was looking at the runway’s end, not the horizon. If I sense the airplane has leveled off, I’ll nudge the stick forward with the thought, “Keep it coming down.” This assures the aircraft continues to descend. Even without flight path vector technology, the pilot needs only to shift his or her eyes to the end of the runway to keep the descent rate going. But there is a little more to it than that, and for that we need to look at some timing.
Folklore: The flare cannot be taught; it is a matter of feel learned through experience.
While much of pilot life is taught as science--think of takeoff data, obstacle avoidance, range performance, etc.--the act of landing the airplane is taught as art. You simply do it under instruction, learn from critique, and adjust until you get it. But as we have seen here so far, you can quantify the act of landing an airplane up to the point you need to pull back on the stick or yoke. We know how to get to flare height and we know what to do after the wheels touch. How do we connect the two? How do you flare an airplane?
In its simplest form, you pull back on the stick or yoke from its existing approach pitch angle and end up at a new angle. That is the “flare rotation.” To bring this art to science, try to pull back in one smooth, continuous motion that ends just as the wheels touch. It would be helpful to know how long this takes. Let’s reexamine our G650’s flare path starting at 25 ft.
When we begin the flare, the MLG will be at 25 ft. and the pilot’s eyes 14.5 ft. higher. The aimpoint will be 39.5 ft. / tan(3deg.) = 754 ft. away. Since the MLG have to travel an additional 42 ft., we know the distance of the flare will be a total of 796 ft. If we assume a ground speed of 120 kt., the flare will take:
Which means you are attempting a smooth, continuous pull on the stick or yoke that takes 4 sec. I think the best flare ends just as you get to the end of your pull while the wheels touch.
The flare can be learned scientifically by instilling the need to begin at a consistent height, pulling back at a consistent rate, and with your eyes pointed at the end of the runway. Each event should be graded looking for a 4-sec. rotation to flare, ending with the wheels touching at the desired aimpoint.
Some of us have been doing this for decades and the thought of grading each landing may seem abhorrent. If you tend to have streaks of good landings and bad landings, this grading approach should help. I find it helpful to write a few sentences describing each landing in retrospect. On a good day: “Stable approach, nice easy pull back, wheels kissed the pavement 4 sec. later right in the touchdown zone, on speed.” On a less than good day: “Crossed the threshold a little low, started the flare too early, ended up over-rotating and landing long.” You will find that after a while a pattern will develop, helping you self-analyze and, more importantly, self-correct.
Remember when grading yourself that the wheels touch behind you and your forward view is obscured by the aircraft’s look-down angle. You will not see the landing in the touchdown zone because your aircraft is blocking the view.
How to Land an Airplane, in Summary
(1) Fly a stable approach, on speed, on the proper glidepath.
(2) Cross the runway threshold at 50 ft. visually or electronically. Remember that if flying visually or on an ILS glideslope, your wheels will be lower than 50 ft. (In our example, that was 35.5 ft. when flying visually.)
(3) Determine the proper flare height based on any flight manual data or on what you have determined by experience. This height can be made evident by electronic means, such as a radio altimeter, but should always be backed up with a point on the runway that you expect to just disappear under the nose. (In our example, a point 600 ft. short of the aimpoint.)
(4) At the proper flare height, shift your eyes to the end of the runway (not the horizon), and using one smooth and continuous motion, pull back to your flare rotation pitch. The pull should take 4 sec. and should end as the wheels touch with the aircraft still in a 100- to 200-fpm descent rate.
Notice that we have not mentioned thrust at all, which will be handled in accordance with aircraft-specific procedures. My technique is to allow the autothrottle “retard” function, if available, to function as designed. This further reduces the number of variables. If operating without autothrottles, I attempt to initiate the reduction at the same time I initiate the pitch rotation, reaching idle as the wheels touch. This has worked on every aircraft I have flown, but I recognize it will not work for others.
One last note for those flying aircraft with unpublished eye-to-wheel and flare heights. The math shown here is for a Gulfstream G650, an aircraft in the 100,000-lb. range that is nearly 100 ft. long. Using a 25-ft. flare height will probably be conservative for smaller aircraft but will give you a starting point. (Remember larger aircraft may have flare heights around 30 ft.) I recommend trying these out in the simulator or seeing what you have been doing in the airplane as a comparison. The first step in any scientific endeavor is observation. I believe you can improve your landings if you approach the landing flare as science, not art.