On the last day of May in 2009, as night enveloped the airport in Rio de Janeiro, the 216 passengers waiting to board a flight to Paris could not have suspected that they would never see daylight again, or that many would sit strapped to their seats for another two years before being found dead in the darkness, 13,000 feet below the surface of the Atlantic Ocean. But that is what happened. Air France Flight 447 carried a crew of nine flight attendants plus three pilots—their numbers augmented because of duty-time limitations on a 5,700-mile trip that was expected to last nearly 11 hours. These were highly trained people, flying an immaculate wide-bodied Airbus A330 for one of the premier airlines of the world, an iconic company of which all of France is proud. Even today—with the flight recorders recovered from the sea floor, French technical reports in hand, plus exhaustive inquests under way in French courts—it remains almost unimaginable that the airplane crashed. A small glitch took Flight 447 down, a brief loss of airspeed indications—the merest blip of an information problem during steady straight-and-level flight. It seems absurd, but the pilots were overwhelmed.

To the question of why, the facile answer—that they happened to be three unusually incompetent men—has been widely dismissed. Other answers are more speculative, because the pilots can nomor longer explain themselves plus had slid into a state of frantic incoherence before they died. But their incoherence tells us a lot. It seems to have been rooted in the very advances in piloting plus aircraft design that have improved airline safety over the past 40 years. To put it briefly, automation has made it more plus more unlikely that ordinary airline pilots will ever have to face a raw crisis in flight—but also more plus more unlikely that they will be able to cope with such a crisis if one arises. Moreover, it is not clear that there is a way to resolve this paradox. That is why, to many observers, the loss of Air France 447 stands out as the most perplexing plus significant airline accident of moderen times.

The crew arrived in Rio three days before the accident plus stayed at the Sofitel hotel on Copacabana Beach. At Air France, the layover there was considered to be especially desirable. The junior co-pilot, Pierre-Cédric Bonin, 32, had brought along his wife for the trip, leaving their two young sons at home, plus the captain, Marc Dubois, 58, was traveling with an off-duty flight attendant plus opera singer. In the French manner, the accident report made nomor mention of Dubois’s private life, but that omission then required a finding that fatigue played nomor role, when the captain’s inattention clearly did. Dubois had come up the hard way, flying many kinds of airplanes before hiring on with Air Inter, a domestic airline subsequently absorbed by Air France; he was a veteran pilot, with nearly 11,000 flight hours, more than half of them as captain. But, it became known, he had gotten only one hour of sleep the previous night. Rather than resting, he had spent the day touring Rio with his companion.