Date & Time:
Dec 2, 1970 at 1600 LT
Hamburg – Tehran - Dhaka
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.
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.