Look out, here comes the runway

Visual effects can either help or hurt you during the landing process. If you see an illusion and don’t recognize it for what it is, that will hurt—often in the form of a bounced landing. If you understand what you are looking at, some illusions can help you.

Let’s look at the landing sequence. The engine’s power is set, the airplane is trimmed, and you are coming on down at the correct airspeed. As you turn final and the runway stretches out before you, now’s the time to choose a suitable touchdown spot. You plan to touch down in the first one-third of the runway.

When you choose that spot, put a sticky note or make a grease pencil mark on the windscreen at the touchdown spot’s location. (Sometimes you might miraculously have a smudge or bug splatter on the wind screen that could work.) You will use this marker as a visual aid to evaluate your glidepath.

If you should practice landing at a wider than normal runway, be prepared for optical illusions to pop up yet again.In Rod Machado’s How to Fly An Airplane Handbook, Machado calls this marker the “stationary spot.” As you ease on down final, with power settings where you want them, the smudge/bug splatter/sticky note/grease pencil mark should remain stationary relative to what’s happening out the windscreen. If it’s moving up, you will land short of it—possibly in the grass. That’s no good. If it’s moving down, you will land beyond it. That’s no good either, especially if you’re accustomed to landing on a long runway and your destination is shorter and narrower.

It’s important not to chase the stationary spot simply by raising or lowering the nose. If the spot is moving upward in your window, add a little power and raise the nose slightly. Now you’ve extended the glidepath while maintaining the necessary airspeed.

If the spot is moving downward in your window, reduce power and lower the nose at the same time. This allows you to steepen the glidepath and maintain your desired airspeed—which would not happen if you simply pointed the nose at the spot and chased after it.

For a short-field landing, Machado notes that you can use the runway threshold as your stationary spot. This will position you to touch down within the first third of the runway. However, you’ll need to ensure the approach is clear of obstacles.

Twenty feet from the ground, you’ll begin the gradual landing transition, where you’ll break the glide and prepare to land the airplane. How do you judge 20 feet? In The Student Pilot’s Flight Manual, William K. Kershner says in just about any light airplane, estimate the height of a hangar and you’ll be fine. Ease the nose toward the landing attitude and continue the descent. At about 1 to 2 feet off the ground you’ll look off to the left and down the runway—not over the nose—and start the flare by maintaining back-pressure. A quick glance to the side can help to confirm your height above the ground. In fact, Kershner advocated keeping your depth perception on alert by scanning the ground as well as up ahead. In other words, don’t fixate on one spot.

Why not look over the nose? Kerschner explained that if you can see over the nose during the flare, you likely don’t have the airplane configured in the correct landing attitude. You may experience an error in your depth perception that could cause you to fly nose first into the ground.

Optical gotchas

OK, the stall horn went off, and you touched down—on the mains first. Yay! Now let’s rewind and go back to final approach and talk about optical illusions pertaining to runway width.

As you pound out landings in the pre- and post-solo stage of flight training, you will become accustomed to the sight picture at your own airport. But, if you should practice landing at a wider than normal runway, be prepared for optical illusions to pop up yet again.

A wider than usual runway can create the illusion that your airplane is lower than it actually is—leading to a higher approach. Conversely, a narrower than usual runway can create the illusion that your airplane is higher than it is, and you may make a lower approach.

You can compensate for this by anticipating the illusion, and of course by referencing any visual approach slope indicator (VASI) or precision approach path indicator (PAPI) light systems that may be in use. Not all airports have a VASI or a PAPI.

What about a runway that slopes downward? Yes, they’re out there; just ask the pilots at Sedona Airport (SEP). Sedona’s Runway 21 has a 1.83 percent downward slope. While most of the time pilots land on the opposite runway, sometimes they must utilize the downward sloping one.

As you approach a downward sloping runway, your brain may tell you that the airplane is lower than it actually is. If you respond by raising the nose and adding power, you’re going to fly a higher approach, which may create problems with your touchdown spot. The reverse is true of an upsloping runway. Your brain may tell you that the airplane is higher than it needs to be, and you may think you’ve got to cut power and push the nose down. This means you will be flying a lower approach.

Night time and flat light

Black hole departures—departing over dark, featureless areas such as bodies of water—can be treacherous for pilots if they become disoriented in the no-horizon situation. But black hole arrivals are a hazard as well. An approach over a darkened area with no lights for contrast can play tricks on your sight picture. The same is true of flying an approach at night over water. As you approach an airport, you may believe you still have the horizon in sight, when in fact you are losing visual references. This can cause you to descend lower and lower until you strike the ground.

Flat light is a wintertime occurrence for much of the pilot population. It can happen when flying over snow-covered terrain beneath an overcast. Flat light can also happen in dust, sand, over mud flats, or flying over glassy water. The conditions can cause pilots to lose depth of field and contrast in vision. “Flat light can completely obscure features of the terrain, creating an inability to distinguish distances and closure rates,” according to the FAA. “As a result of this reflected light, it can give pilots the illusion of ascending or descending when actually flying level.”

If flying in flat light, visual references are key. Don’t fly until you have only one visual reference left, the FAA says. “Try not to lose sight of your reference point at any time. Plan your approach so that your reference is always on your side when flying. Never turn away from your reference point. Fly with your head straight, looking forward; believe what your flight instruments are showing you.”

Can you opt out of these optical illusions? No, but you can prepare yourself for them. Remember FAR 91.103: “Each pilot in command shall, before beginning a flight, become familiar with all available information concerning that flight.” Review the pertinent information for any airport you intend to visit. Check runway width, slope, and gradient. Look for guidance lighting systems (or lack thereof). Remind yourself what you’re likely to encounter, and how you will compensate for it.

Finally, keep a go-around ready. Despite your best efforts, an optical illusion may get the better of you. If you misjudge the approach, go around and try again.

[email protected]