What happened
During an approach to Bangkok-Don Mueang Airport, the crew encountered severe weather characterized by heavy rainfall and low visibility resulting from a tropical storm. The approach was being managed by the copilot when the Instrument Landing System (ILS) malfunctioned. Despite this equipment failure, the decision was made to proceed with the landing attempt. At an altitude of 700 feet, the pilot-in-command identified the runway lights, though the aircraft type was positioned too far to the left and slightly above the intended glide path.
As the descent continued, the aircraft reached 300 feet while maintaining an indicated airspeed of 127 knots, which was approximately five knots faster than the planned approach speed. In an attempt to correct this, the copilot initiated a reduction in speed to 122 knots. During this maneuver, the plane experienced a sudden loss of altitude. The captain attempted to recover control of the aircraft, but the descent rate became too high to stabilize. The resulting hard impact caused both main landing gear to puncture the wings. The aircraft traveled several hundred yards before coming to a stop. While there were no injuries among the 75 occupants, the airframe was declared a total loss.
Findings
Investigations into the incident suggest that windshear may have been the primary factor contributing to the sudden loss of altitude and the subsequent uncontrolled descent.