Incident Description
On a cargo service designated flight IBT1278, a twin-engine airplane departed Madrid-Barajas Airport at 0635 local time bound for Bilbao. The aircraft carried a crew of two pilots and one company mechanic, along with a cargo load of 2,873 kilograms of various goods.
The flight was uneventful until the crew was cleared to begin a descent to Bilbao-Sondica Airport for an Instrument Landing System (ILS) approach to runway 30. During the descent, the pilots encountered control problems, which they attributed to an autopilot malfunction. While attempting to identify the issue, the crew failed to notice an increasing rate of descent. The Ground Proximity Warning System (GPWS) sounded three alarms. Shortly thereafter, as the crew attempted to gain altitude, the aircraft struck the slope of Mount Santa Marina Vieja, located 33 kilometers from Bilbao Airport.
The impact destroyed the aircraft, and all three occupants were killed. The wreckage was discovered near the village of Zaldíbar.
Investigation Findings
The official investigation determined that the probable cause of the accident was controlled flight into terrain (CFIT). The crew lost adequate separation from the ground because their attention was focused on troubleshooting the disconnection of the autopilot system. Additionally, the crew failed to follow the Standard Operating Procedures (SOPs) published by the operator.