What happened
On a cargo flight operating as IBT1278, a twin engine airplane departed from Madrid-Barajas at 06:35 local time, destined for Bilbao. The flight was transporting 2,873 kilograms of cargo along with a crew consisting of two pilots and one company mechanic.
As the aircraft began its descent toward Bilbao-Sondica Airport for an ILS approach to runway 30, the crew experienced issues with flight controls. The crew believed these difficulties were caused by a malfunction in the autopilot system. During the process of troubleshooting the control issues, the aircraft's rate of descent increased significantly. Despite the GPWS alarm sounding three times, the crew did not realize the danger posed by the rapid loss of altitude.
In an attempt to recover altitude, the aircraft struck the terrain at the slope of Mt Santa Marina Vieja, situated approximately 33 km from the destination airport. The impact destroyed the aircraft, and all three occupants were killed. The debris was located in the vicinity of the village of Zaldíbar.
Findings
- The crew experienced control problems which were attributed to an autopilot malfunction.
- There was a failure to recognize the increasing rate of descent despite multiple GPWS warnings.