What happened
On June 27, 2003, a SOCATA TB-20, registration D-EKBI, departed Madrid-Cuatro Vientos Airport for Bilbao Airport as a private VFR flight. The flight initially proceeded normally through clear skies, maintaining a level of 7,300 ft. However, as the aircraft approached the Cantabrian mountain range, the weather conditions deteriorated. Clouds began to accumulate over the mountains, with bases ranging between 2,500 and 3,5 and tops exceeding 7,000 ft.
At approximately 12:11 UTC, the pilot established contact with Bilbao Approach Control. During the exchange, the controller noted that the pilot was having difficulty maintaining visual contact with the ground. The pilot indicated they were descending to 4,000 ft and were searching for a mountain pass to descend further to 2,000 ft. Shortly after, the aircraft's communications ceased, and radar contact was lost. The aircraft subsequently struck a mountain slope at an elevation of 3,780 ft near Pico de Aro. The impact resulted in two fatalities.
The investigation
The investigation examined the flight path, meteorological conditions, and communications between the aircraft and Bilbao Approach. Investigators analyzed the wreckage, which showed the aircraft had struck the terrain at high speed, causing the engine, propeller, and wings to detach and the cockpit to disintegrate. The investigation also reviewed the radar tracks and the radio transcripts between the pilot and air traffic services.
Findings
- The aircraft was flying under Visual Flight Rules (VFR) but encountered Instrument Meteorological Conditions (IMC) due to heavy cloud cover over the high terrain.
- The pilot lost clear visual contact with the ground while attempting to navigate through the mountains.
- The aircraft was flying at a high speed, which likely prevented the pilot from executing an effective escape maneuver once the terrain appeared.
- The Bilbao Approach controller had no prior knowledge of the aircraft's arrival, as the flight reached the TMA earlier than estimated.
- Communications between the pilot and the controller were technically difficult and difficult to understand.
- There was no evidence of mechanical or functional failure in the aircraft's engine or systems prior to the impact.