Background
The aircraft involved was a four-engine aircraft named Willem Bontekoe. It was operating a flight from New York to Amsterdam-Schiphol Airport, with an intermediate stop at Shannon. The flight was uneventful until the approach to Schiphol.
Accident
During the approach, the crew received permission to descend to 5,500 feet, followed by clearances to 4,500 feet and then to 3,500 feet. At approximately 1130 local time, the aircraft disappeared from radar after crashing into the sea. About five minutes later, air traffic control cleared the crew to descend to 2,500 feet, but no acknowledgment was received.
Search and Rescue
Search and rescue operations were hindered by poor weather conditions. The first debris was located at 1610 local time, about 37 kilometers northwest of Ijmuiden. None of the 21 occupants survived the crash. Less than 50% of the aircraft wreckage was recovered.
Investigation
A 15-month investigation was conducted. Several hypotheses were explored, including overheating of the electrical system with heavy smoke development, explosion of a high-pressure bottle, failure of a cockpit window, and failure of the automatic pilot system. However, none of these possibilities could be developed into a comprehensive explanation that fit all the evidence.
Probable Cause
In November 1955, the investigation concluded that the cause of the accident could not be established.