What happened
A cargo mission operated on behalf of the International Red Cross Committee ended in a fatal accident during its arrival at Dhaka-Tejgaon Airport. The aircraft, transporting 27.5 tons of food supplies from Hamburg via Tehran, was performing its final approach when it lost controllability. The plane struck several residential structures located approximately 10 km northwest of the airfield.
The impact resulted in eight fatalities, consisting of all four crew members on board and four individuals residing on the ground. No survivors were reported among the occupants of the aircraft.
Findings
Investigations into the accident identified a critical failure within the aircraft's hydraulic systems. It was determined that the hydraulic gust lock system engaged while the plane was in flight, which effectively immobilized the flight controls. Specifically, the rudder became stuck in a neutral position, while the ailerons were locked in an upward orientation.
Technical analysis suggested that a malfunctioning switch valve caused hydraulic back pressure to accumulate when the systems were armed during the descent phase. This instability followed a significant hydraulic contamination event that had occurred during a prior flight near the Azores Islands. Furthermore, the aircraft's history included a previous emergency landing in Madrid after both hydraulic pumps failed during takeoff, leading to a total loss of hydraulic pressure.