KLM Flight 607 E

KLM Flight 607-E, flown by Lockheed Super Constellation named Hugo de Groot and registered PH-LKM, was an international scheduled flight that crashed 180 kilometres (110 mi) west of Shannon, Ireland on 14 August 1958. All ninety-one passengers and eight crew died in the accident, including six members of the Egyptian fencing team (Osman Abdel Hafeez, Mohamed Ali Riad, Ahmed Sabry, etc.). The "E" in the flight number stood for the designation of being an extra economy class flight to match the increased seasonal tourist demand.

Flight 607-E departed Shannon at 3:05 UTC on the second leg of a transatlantic trip from Amsterdam to New York City with intermediate stops in Shannon and Gander, Newfoundland. Radio contact with the aircraft was lost at approximately 3:40 UTC; a rescue operation was launched which found light debris on the surface of the ocean approximately 180 km west of Shannon. The remains of thirty-four of those on board were also recovered.

Due to the lack of evidence, Irish and Dutch investigators could not pinpoint a probable cause for the accident. They examined the possibility of a bomb, electrical failure or pilot error, but believed that the most likely possibility was a catastrophic mechanical failure. The cause of the accident is believed to be a malfunctioning overspeeding outboard propeller caused by metal particles obstructing oil feed line regulator valves. The particles may have been formed by a gear that was damaged when the supercharger of the corresponding engine was accelerated (gear ratio shifted). The malfunctions of the propeller pitch might have provoked a flight disturbance and as a consequence the propeller may have sheared off.