The Moon Wears A Sombrero

I flew in to Charlottesville last Thursday night in astonishingly bright moonlight. I didn't realize it, but the harvest hunter's full moon was on duty, and it had lit up the cloud tops right out to the horizon. You could count the rivets on the wing. There was a thick layer of stratus cloud just below us, with only an occasional gap giving away our true altitude, revealing a spider web of roads and subdivisions down on the ground.

As we neared Charlottesville, the plane made a long left turn to start its approach, and suddenly out popped the giant yellow moon. It was floating just above the horizon and wearing a long cloud on his head that looked exactly like a sombrero hat. All that was missing was the ball fringe.

“Buenas Noches,” I thought.

I've been flying a lot this week - my itinerary makes a nice ASCII necklace:

BTV -> BOS ->ATL ->CHO ->CIN ->BTV ->MHT ->EWR ->YHZ

By some great luck, I have been seeing wonderful things from the plane all week. On the flight into Atlanta, there was thick overcast covering the city, and the plane descended into a sickly yellow world. The air was clear, but saturated with water. When the pilot extended the flaps for final approach, the entire wing burst into fog, from root to tip. Though the air around us was clear, the rear half of the wing was enveloped in a private, roiling cloud. It looked like someone had glued a hundred tons of cotton balls to the wing.

Many frequent fliers have seen the little wake vortices that sometimes spin off of a wing tip or a spar, but this was the first time I'd seen a whole wing swallowed up. A web search shows that condensation above lifting surfaces is very common, especially on military aircraft. That link points to the wonderful Gallery of Fluid Mechanics, which has photographs of all kinds of condensation and vortex action. In addition to garden-variedy wing fogs, there are more esoteric phenomena like the Prandtl-Glauert singularity, which is a condensation cloud that resembles a shock front. In this astounding movie clip, you can see a singularity form behind an F-16, disappear, and then re-form. Notice how severely the cloud buffets the plane - when the cloud re-forms, you can actually see the nose of the plane get shoved down. There's more info on the associated web page.

I flew from Charlottesville to Cincinnati at the black hour of six o'clock, the time when baggage handlers toss a football and the rest of the world sleeps. The airplane arrived over Ohio just as the pre-dawn twilight was brightening enough to show the ground, and I saw a giant snake of cloud eating its way across the landscape. It was the Ohio river, covered with thick morning fog. The scale of it was enormous—long tendrils of fog reached out into hollows, surrounding helpless towns. The Midwest was under attack by a giant angora python, and I was the only one who knew.

I've found that people who are not afraid of flying have little patience for people who are. We are the secret fraternity of armrest grippers; those who sit through takeoffs with eyes closed even though they aren't trying to sleep, others (my brothers!) who are compelled to stare out the window at the first tremor of turbulence, making sure the outside world doesn't flip over, and that the wings remain securely fastened to the sides of the plane.

Whenever I am particularly anxious about a flight, I buy an issue of Flying magazine to take on board with me. It is a balm for the scared traveller. Flying is aimed at the general-aviation pilot, weekend flyers who buzz around in small planes, and each issue is like a reassuring sermon. Hidden among all the GPS reviews, air show reports, and ads for airline training school is a morality tale, where the angels are Prudence, Sound Planning, Thoroughness, and Preparation, and the devils are Fatigue, Bad Luck, and Trying To Fly Under Visual Flight Rules In Marginal Weather Conditions. Pilots are exhorted to be Thorough, Prudent, and Practice Sound Planning, and are given vivid examples of what will happen if they do not. Each issue has a special section of FAA reports on recent crashes, a terse description of the incident followed by the body count, and where blame should properly be assigned. “March 30, 2002, On Approach to Talahassee. Injuries: 2 Fatal.” There's also a regular column called “I Learned About Flying From That”, which might as well be called "How I Almost Bought It In My Airplane", and my favorite column, "Aftermath", where the author takes us through a single spectacular crash, detailing each fatal misstep leading to the gruesome accident.

The reason I find all this reassuring is because of the unspoken subtext that commercial air travel is really, really safe. General aviation pilots have a bit of a complex, because their fatality rate is uncomfortably high compared to road travel, let alone the utter safety of commercial aviation. This is exactly what I want to be reminded of when I am in a little Embraer jet at 37,000 feet, shaking like a Jello mold. In Flying magazine, you never see a report that says "Embraer pilot lost control of jet after wings snapped off in clear air turbulence. Injuries: 43 fatal". Instead, it's always "Piper cub pilot without instrument rating flew into thunderstorm", or "pilot became disoriented after flying into clouds at night", or "pilot allowed plane to enter graveyard spiral, overcorrected at 500 feet, plane broke up in flight".

Of course, there's a limit to the comfort you can get from a magazine in the stratosphere. But you take what you can get. I was heartened recently to discover that, after all this time, I had been wrong about what makes a plane fly in the first place. Instead of some dubious business about low pressure above the wing, there's the comforting thought of the plane pushing tons and tons of air down as it flies. I like the idea of the plane working hard to keep me in the air, not just relying on some kind of suction. So instead of Bernoulli, these days I fly with Isaac Newton. It's nice to look out over the wing and think I'm being kept aloft by sound English science, rather than some dodgy Continental quack.