KLM Flight 607-E

KLM Flight 607-E
The Hugo de Groot
Accident summary
Accident type	unknown
place	West of Shannon across the Atlantic
date	August 14, 1958
Fatalities	99
Survivors	0
Aircraft
Aircraft type	Lockheed L-1049H-01-06-162 Super Constellation
operator	KLM
Mark	PH-LKM
Passengers	91
crew	8th
Lists of aviation accidents

On August 14, 1958, a Lockheed L-1049H Super Constellation (name: Hugo de Groot , aircraft registration : PH-LKM) of the Dutch airline KLM crashed on KLM flight 607-E west of Shannon over the Atlantic . All 99 inmates were killed. The definitive cause of the accident could not be determined. The "E" in the flight number stood for "extra" . The flight was set up in addition to the regular KL607 scheduled flight to meet the seasonally increased demand.

Construction and commissioning

The Hugo de Groot was a machine of the last Constellation variant L-1049H, which was manufactured from 1957 and was intended for mixed passenger and freight traffic. The Hugo de Groot had two large cargo hatches on the port side of the hull. In addition, a reinforced heavy-duty floor was installed as a so-called roller floor, which made it possible to use floor conveyors for transport pallets.

The Hugo de Groot was built in 1958 with the serial number 4841 and received the license plate PH-LKM . The aircraft was named by KLM after the Dutch theologian, philosopher and enlightener Hugo Grotius (1583-1645).

crash

The Super Constellation was on the second leg of a transatlantic flight from Amsterdam to New York City with stopovers in Shannon and Gander , Newfoundland . The machine started on August 14th from Shannon at 03:05 GMT for its Atlantic crossing to Gander. On board were 91 passengers, the captain and copilot as well as six other crew members. The last radio contact with the aircraft was at 03:40 GMT, 35 minutes after take-off. After that there was no more contact.

The crash likely happened around 200 kilometers (110 nautical miles) west of Shannon, Ireland, across the Atlantic Ocean. Wreckage was found in the sea in this area north-northwest off the Irish coast. The calculated position of the machine located them further on the Atlantic, which is why it was assumed that the pilots had tried to turn around after a technical problem. The bodies of 34 of the people were recovered. Rescue was not considered due to the unknown depth of the crash site.

Background and cause

The investigation report by the Irish and Dutch investigators after the crash could not identify a clear cause of the crash. With a certain probability, it was assumed that one of the two outer motors was overspeeding from a propeller due to dirty engine oil. The control valves of the regulator of the constant-speed variable-pitch propeller , which is supplied with pressurized oil as a working medium by the engine lubrication, could have been impaired by possible metal particles , so that the angle of attack of the propeller blades of the engine concerned decreased inadmissibly, and on the other hand the low-resistance wing position (feathering) the propeller could not be brought about. Because the angle of attack is too low for the flight speed, there is no more propulsive force, instead a braking torque, despite the maximum increase in engine speed compared to the remaining three, correctly working engines. As a result, if the crew does not immediately recognize the situation and counteracts it consistently with countermeasures, the asymmetrically distributed propulsion forces can lead to an uncontrollable flight condition that could have led to a crash. Hypotheses that pilot errors or a bomb explosion led to the crash, the report classified as unproven hypothesis.

The Hamburg news magazine Der Spiegel reported in detail in August 1958 about the crash of the Super Constellation and the delayed search for the machine due to lack of radio traffic. Disturbances in radio communications over the North Atlantic were commonplace in aviation at that time. After the Hugo de Groot did not report by radio as scheduled, air traffic control in Shannon initially limited itself to informing shipping via the coastal radio station " Valentia Radio " in Ireland that the aircraft had no longer reported. Position details or a calculated course were not given, so that shipping could not do anything with this information. Der Spiegel wrote that the radio communication between aircraft and ground station was "paradoxically due to a technical innovation" . Some airlines, including KLM, had abolished Morse code in transatlantic traffic in accordance with the safety recommendations of the international civil aviation organization ICAO and only used radio communications. The KLM plane that crashed over the North Atlantic therefore had no full-time radio operator on board. Before the crash, the KLM management stated: “The radiotelephone has proven itself. It makes the transmission of messages between the radio operator and the pilot, which can easily lead to misunderstandings, superfluous, because the pilot receives or gives all messages himself. "

At that time, radio experts did not rule out the possibility that some of the survivors might have been rescued if a standard telegraph radio had been on board the machine for emergencies. Experts and others concluded that a professional radio operator might still have found time to send an emergency call. a. from the evidence that a child was found by the rescue ships who had been put on a life jacket. In the event of a sudden crash or explosion, there would have been no more time.

In the machine there were also six members of the Egyptian national teams in fencing .

consequences

After the accident, the investigation commission took good note that the governor (governor) of the variable pitch propeller were equipped with safety mechanisms to ensure that the adjustment reliable feathering (feathering) causes the propeller blades. Based on the results of the investigation, the investigation report also recommended disconnecting the pressure oil supply to the propeller governor from the engine lubrication in order to avoid malfunctions of the propeller adjustment due to contamination in the oil.

Individual evidence

1. ↑ KLM, Lockheed Constellation L-1049H, PH-LKM ("Hugo de Groot"), accident over the Atlantic Ocean near Ireland on August 14, 1958. Findings of the Accident Investigation Board as released by the Director General of Civil Aviation, The Netherlands - 9 June 1961. (PDF) In: ICAO Circular 64-AN / 58 Aircraft Accident Digest No. 12. International Civil Aviation Organization, Montreal, 1963, pp. 23-30 , archived from the original on November 14, 2016 ; accessed on November 14, 2016 . 
2. ^ Accident. Aviation Safety Network, accessed March 21, 2014 . 
3. ↑ Without radio operator. Der Spiegel , August 27, 1958, accessed on March 21, 2014 . 

Coordinates: 53 ° 12 ′ 30 ″  N , 11 ° 53 ′ 0 ″  W.