Cargolux aircraft accident in 1970

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Cargolux aircraft accident in 1970
Cargolux Canadair CL-44J Haafke.jpg

An identical aircraft from the airline
Accident summary
Accident type Loss of control after activating the rudder locks in flight
place Dhaka , East Pakistan , Pakistan (today: Bangladesh )
PakistanPakistan 
BangladeshBangladesh 
date 2nd December 1970
Fatalities 4th
Survivors 0
Injured 0
Fatalities on the ground 3
Aircraft
Aircraft type CanadaCanada Canadair CL-44 J.
operator LuxembourgLuxembourg Cargolux
Mark IcelandIceland TF-LLG
Departure airport Luxembourg Airport , LuxembourgLuxembourgLuxembourg 
1. Stopover Hamburg Airport , GermanyGermanyGermany 
2. Stopover Tehran Mehrabad Airport , IranIranIran 
Destination airport Dhaka-Tejgaon Airport , East Pakistan , Pakistan (today: Bangladesh ) PakistanPakistan 
BangladeshBangladesh 
Passengers 0
crew 4th
Lists of aviation accidents

The Cargolux accident in 1970 occurred on December 2, 1970 on an intercontinental charter cargo flight operated by Cargolux from Luxembourg to Dhaka with stopovers in Hamburg and Tehran . On that day, a Canadair CL-44 J crashed into a settlement due to a malfunction of the hydraulic system on approach to the former main airport Dhaka-Tejgaon , killing seven people.

machine

The aircraft was a Canadair CL-44J with the serial number 36 , which was six years and eight months old at the time of the accident. The machine completed its maiden flight on March 25, 1964, before it was delivered as the Canadair CL-44D4-8 to its customer, the Icelandic Loftleiðir , on September 25, 1964 and was put into operation with the aircraft registration TF-LLG and the name Vilhjálmur Stefánsson . In 1965 the machine was transferred back to Canadair and modified there to a Canadair CL-44J, before it was returned to Loftleiðir and was put back into operation on May 1, 1966. On August 11, 1970, the machine was handed over to the newly founded Cargolux as the second machine in its fleet, where it was converted into a freight machine. The machine kept its Icelandic registration number, as Loftleiðir was one of the founding companies of Cargolux. The four-engine long-haul cargo plane was equipped with a swing-tail and four turboprop engines of the type Rolls-Royce Tyne 515 equipped.

crew

There was a four-person crew on board, the three-person cockpit crew being Icelandic. The captain was the 36-year-old Ómar Tómasson (born February 1, 1934), first officer the 30-year-old Birgir Örn Jónsson (born September 11, 1940) and flight engineer the 32-year-old Stefán Ólafsson (born February 27, 1938). The 32-year-old Luxembourg Cargolux employee Jean-Paul Tompers also flew as a load master and ground mechanic.

Purpose of flight and cargo

The flight served as humanitarian aid for flood victims after the cyclone in East Pakistan in 1970 . The machine was chartered by the Swiss Red Cross as a member of the International Red Cross and Red Crescent Movement . The cargo consisted of 27.5 tons of baby food .

Course of the flight and course of the accident

The machine was flown on December 1, 1970 at 3:00 p.m. local time from Luxembourg to Hamburg, where 27.5 tons of baby food were loaded for flown to Dhaka. After a stay of several hours in Hamburg, the machine flew in the direction of Dhaka, with an unscheduled refueling stop in Tehran on the way . After a one-hour stay in Tehran, the aircraft flew further east on December 2 at 6:00 a.m. local time, and was scheduled to arrive in Dhaka at 4:00 p.m. local time. Shortly before the planned arrival, about 10 kilometers northwest of the destination airport, the captain suddenly lost control of the aircraft. The CL-44 crashed into a settlement and buried several farmhouses under itself. All four inmates and three people on the ground, including two children, were killed. At this point in time, the crew had been on duty non-stop for around 18 hours.

root cause

The cause was probably an automatic activation of the hydraulic rudder lock during the flight, which suddenly locked all the rudders and the machine could no longer be controlled. The purpose of the rudder lock was to prevent undesired movement of the rudder and possible damage to the ground caused by gusts , and its activation in the air was considered impossible. The investigators suspected, based on the flight history of the machine before the crash, that the rudder was locked in the neutral position. It was also assumed that the hydraulic back pressure had built up due to a faulty switching valve when the hydraulics were heavily used in the descent phase.

It was found that the hydraulic systems had already been heavily contaminated on an earlier flight from the Azores . Both hydraulic pumps failed at take-off, which led to a total loss of hydraulics and forced the crew to carry out the planned flight to Madrid with the landing gear down. The machine was then flown to Prestwick , where it was repaired by Scottish Aviation . This incident is not mentioned in the official accident report.

consequences

Cargolux later modified the CL-44 system by installing a pressure equalizer that could be activated by the flight crew. Most other airlines' CL-44s were fitted with a similar system modification, while some airlines only disabled the system and used external rudder locks. This in turn led to an accident on February 27, 1975 on Aerotransportes Entre Rios flight 501/90 , when a machine at Miami International Airport overshot the end of the runway because the crew had forgotten a temporary wooden rudder lock before departure to remove.

The incident had no major consequences for the day-to-day business of the newly founded Cargolux, as it was already operating five Canadair CL-44s in 1972. Up until the company's 50th anniversary in March 2020, the company had not had another fatal incident.

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