It is as if Air France 447 crashed in the middle of the Bermuda Triangle -- even though the Bermuda Triangle is thousands of miles away from the crash site, and most pilots will tell you its dangers are nothing more than urban legend.
Still, this was a tragedy of unusual proportions. The plane fell from the sky in mid-flight, something that almost never happens in modern aviation. The cause is still a mystery; the pilot is reported to have sent a text message about stormy weather, and the plane sent automatic signals reporting an electrical fault, but not more. 228 people are believed dead.
Recovery experts say the equatorial Atlantic where the plane went down is an especially bad place for a plane crash. The waters there, not far from where Atlantic hurricanes take shape, are often stormy. And the ocean floor near the mid-Atlantic ridge is deep and uneven, worsening the chances of recovering anything from the Airbus 330, which went down on a flight from Brazil to France.
"If I were to put this on a scale of one to ten of bad, it's up there," said Robert Ballard, the famed ocean explorer who, among other things, led the expedition that found the RMS Titanic in 1985. "It's not a ten. The worst place you could lose something would be up in the polar regions or up in the high latitude areas."
John Perry Fish, vice-president of American Underwater Search and Survey, a firm that specializes in difficult salvage operations, had his own list of concerns. "Uninhabited regions that have inhospitable climates -- for instance, winter near the poles," he said. "If the prevailing winds are 30 knots [about 35 miles per hour] there may be only one day in a month that you can actually work."
Very few planes go down in mid-flight. Most aviation accidents happen on takeoff or landing. That's part of the reason, aside from simple economy, that aviation authorities are willing to let commercial flights cross over places that would be especially treacherous in the event of an accident.
The South Pacific: with its wide-open stretches of water and tropical climate, storms there can be larger and more violent than elsewhere, with few places to land if a plane needs help. We still don't know what happened to Amelia Earhart.
The Arctic: planes from the eastern United States to the Pacific Rim routinely fly over northern Canada and Alaska, and there's been unease over routes that take them closer to the pole, even if it would be more direct.
The North Atlantic: flights between the U.S. and Europe go over the stormy waters off the Canadian Maritimes -- including, sometimes, the area where the Titanic went down in 1912.
Meteorologists worry about large storms, especially in warm climates. Air France 447 was passing through the "Intertropical Convergence Zone" --- a region near the equator where conditions are ripe for daily thunderstorms.
"Try to imagine the atmosphere expanding if the temperature is high," said Henry Margusity, a senior meteorologist at AccuWeather.com, the weather forecasting service. "A major storm in the North Atlantic will top out at, say, 28,000 feet, while a thunderstorm in the tropics could reach 60,000 feet. There's no way to fly over it."