Date & Time:
Dec 2, 1970 at 1600 LT
Type of aircraft:
Canadair CL-44
Operator:
Registration:
TF-LLG
Flight Phase:
Landing (descent or approach)
Flight Type:
Humanitarian
Survivors:
No
Site:
City
Schedule:
Hamburg – Tehran - Dhaka
MSN:
36
YOM:
1964
Country:
Bangladesh
Region:
Asia
Crew on board:
4
Crew fatalities:
4
Pax on board:
0
Pax fatalities:
0
Other fatalities:
4
Total fatalities:
8
Circumstances:
The aircraft was completing a humanitarian flight from Hamburg to Dhaka with an intermediate stop in Tehran, carrying a crew of four and 27,5 tons of foods on behalf of the International Red Cross Comity. On final approach to Dhaka-Tejgaon Airport, the airplane went out of control and crashed onto several houses located in a district 10 km northwest of the airport. All four crew members were killed as well as four people on the ground.
Probable cause:
It appeared that the hydraulic gust lock system activated in flight, causing the controls to lock. It is believed the rudder was blocked in neutral position and the ailerons in a upper position. Also, it is believed that hydraulic back pressure had built up because of a malfunctioning switch valve when hydraulics where armed on descent. The aircraft already suffered a major hydraulic contamination during a previous flight in the Azores Islands. On takeoff, both hydraulic pumps failed, causing a total hydraulic loss and forcing the crew to fly gear down to Madrid.
