The aircraft had a name. KLM christened most of its DC-6Bs after Dutch maritime figures, and this one - construction number 43556, line number 257, delivered in August 1952 - carried the name Willem Bontekoe, the seventeenth-century captain who survived the explosion and shipwreck of his East Indiaman and wrote a famous account of getting home. Reregistered as PH-DFO in March 1954, the aircraft had been flying KLM's transatlantic routes for two years. New York to Shannon to Amsterdam was a routine pattern. The Atlantic crossing had gone normally. Shannon to Amsterdam was supposed to be the easy part.

The weather over the Dutch coast that morning was poor: low cloud, heavy rain, the kind of conditions that make people on the ground squint upward when an aircraft passes overhead. Several of them did. Witnesses near Egmond reported hearing the DC-6B cross the coast on the Green 2 airway around the time of its descent clearance. Others reported seeing it pass over again at 12:01, low, heading back out to sea. A few said they heard a loud bang over the water - possibly an explosion. None of the accounts agree on more than the strangeness of what they saw. Whatever was happening in the cockpit of Flight 608 in those final minutes, it included at least one course reversal and an aircraft no longer following its clearance.

Salvage work began almost immediately, using an experimental sonar system developed at the Dutch Physics Laboratory - early postwar underwater acoustics being tested in earnest on a real wreck. By 25 November, crews had recovered roughly 45 to 50 percent of the aircraft. It was not enough. The cause of the crash was never determined. Investigators offered several possibilities: an electrical fire, a pressure-bottle explosion, a cockpit window failure, autopilot trouble. The most carefully argued theory came from a State Aviation Authority investigator who pointed at the cabin heater. Fumes from a malfunctioning heater, the theory went, would have driven the crew to open a cockpit window for fresh air. Fire risk would have demanded they cut the electrical system. That would explain the radio silence. It explains, too, why witnesses saw an aircraft that was still flying but no longer responding.

The dead included a child. The passenger manifest carried Dutch, American and other names, businessmen and tourists and a family in transit, the routine summer cross-section of a transatlantic flight in the early jet age - except this was a piston airliner on the cusp of being replaced, a generation of aircraft and crew who learned to fly the Atlantic when the Atlantic was still long. Bodies came ashore on the Dutch coast in the weeks that followed. Some did not. The Willem Bontekoe, named for a captain who survived a shipwreck and made it home with stories, lies in pieces on the seabed somewhere off IJmuiden. The 21 people on board never finished their crossing.