By Robert N. Rossier, EAA 472091
This story first ran in the October 2019 issue of EAA Sport Aviation.
Night can bring some of our most memorable flights — some sparkling and magical, but others a bit on the frightening side. We know that an airplane can fly just as readily in the darkness as in the day. The airplane doesn’t know the difference. But we as pilots have limitations, and the failing of daylight can put us in a completely new environment. A blanket of darkness can make even familiar terrain completely alien and play tricks on our visual senses. The problem is sometimes what we see and, in many cases, what we don’t see. And then there’s our imagination to deal with. Somehow, at night, the engine is suddenly on auto-rough, and every bump is enough to jolt us out of our seat. Is there really a problem, or are we just on a hair-trigger? There may be magic in the air, but there are also illusions and confusion.
A Problem?
Flying through the mountains of Colorado at night can be much like flying in a sensory deprivation tank — nothing but sheer blackness. For the pilot of a small general aviation aircraft, it’s a situation to be avoided. So, imagine just such a flight, in a light twin flying high above rugged terrain in the stunning darkness. Everything seems fine. Then you look out the window and see an eerie blue glow coming from beneath the engine. What the heck is that? You’ve never seen that before. Your heart rate rises sharply as you ponder the possibility that it might be an engine fire. Maybe you should shut it down, but you wonder about the altitude you will lose and the elevation of the terrain below. Suddenly every unseen peak and rocky crag is an ugly claw with razor-sharp talons ready to pluck you out of the sky. But, as you’re about to pull the mixture back to shut down the suspect engine, it comes to you: Maybe it’s just the glow of the exhaust. And sure enough, as you adjust the mixture, you see the changes in color. It’s normal; you’ve just never noticed it before.
Weather Gone Awry
Imagine it’s a brisk and dark fall night and you’re on a relatively short flight to a neighboring town or city. Ceilings are comfortably high, the visibility better than 10 miles, and you feel confident flying in a familiar aircraft with plenty of fuel. You’re no more than 35 miles or so from your destination, and the landscape is dark — not even the slightest shimmer of city lights ahead. But out of nowhere comes the most amazing sight: With each flash of the wingtip strobe comes a glittery sparkle that appears not unlike fairy dust. You watch in wonder and amazement for a moment until finally coming to a stunning realization: It’s snow. You turn on the landing light, and the dizzying scene confirms you’re indeed flying through a snow shower. Your confidence pales as you peer through the darkness estimating how far it is to your destination airport. Stories of pilots and icing flash through your mind. This is not good. You momentarily flail in the darkness to pull a flashlight out of your flight bag and focus the beam on the leading edge or strut, studying the airframe for signs of icing. Nothing sticking yet. Good news. ETA for your destination is a mere 15 minutes, but right now it seems like an eternity.
Illusions
Perhaps even more disorienting than what we do or don’t see at night is what we think we see. Illusions at night are both common and powerful. They can cause us to depart from our intended course of flight or make decisions that have dire consequences. What seems to foul us up at night is the juxtaposition of lights and darkness, creating patterns that we interpret as something other than what they really are.
Again, it’s a moonless night, and you’re flying along the coast of Maine. The night is clear, but lighting is sparse in this unpopulated area. After checking the engine instruments, your gaze returns to the night sky, with its piercing pinpricks of shimmering light from the heavens. And as your gaze lowers, you realize that you must be in a bank. The horizon is not where it should be. You must have raised a wing when your head was in the cockpit. You lower the wing, trying to find the horizon. But somehow it just isn’t there. This isn’t feeling right. Your pulse quickens as you glance at the instruments, which also are not making sense. What the heck is going on?
What Is Wrong?
Finally, your training kicks in, and you realize you must trust the instruments. Focusing on the attitude indicator, you bring the airplane back to straight and level flight. It feels wrong for a moment, but as your senses slowly adjust it begins to feel right again. The only thing wrong is that you’ve lost some altitude — quite a bit actually. You pitch the nose up and add power to regain a comfortable cushion above the rocky shoreline below.
As the lights of a coastal fishing port come into view, the trickery of the night sky suddenly becomes obvious. In the clear night, the lights of fishing boats blended with the stars in the sky, creating the illusion that the horizon had somehow moved. Only your trust in the instruments could bring you back from the brink.
That’s not the only scenario that tricks our senses into perceiving a false horizon. Imagine flying over featureless terrain on a dark night with no moon or stars for illumination or orientation. You’re uneasy as you monitor your altitude and maintain heading, flying headlong into the void. Somewhere ahead, you know, is your destination, and surely the glow of civilization will soon emerge from the inky blackness. When the line of lights finally does appear, you realize it’s none too soon, and level your wings to the horizon. Only it’s not the horizon at all — just a row of lights along a highway angling off into the distance. Once again, you struggle to maintain a proper attitude, but the picture outside doesn’t match the crazy indications of the instruments.
The effect is paralyzing, confusing, and potentially deadly.
The Final Approach
The runway lights of an airport on an island, along the coast, or set in an unpopulated rural location can seem like a visual oasis — a beacon guiding us safely to the ground. Especially when that runway lines up on our nose, it’s tempting to eyeball the shimmering rectangle of lights and start our descent for a straight-in landing. But many pilots misjudge the distance and unwittingly descend into trees or terrain when doing so. The wise pilot knows to resist the temptation, overfly the airport at pattern altitude, and then enter the pattern for a normal approach or landing.
Nothing is as magical as a night flight, but along with that magic can come trickery and deceit. The more we learn about the subtle tricks the night can play on us, the better prepared we are to avoid the illusions and confusion, and just enjoy the magic.
Robert N. Rossier, EAA 472091, has been flying for more than 30 years and has worked as a flight instructor, commercial pilot, chief pilot, and FAA flight check airman. For more from Robert, read his column, Stick and Rudder, each month in EAA Sport Aviation.