Investigation Summary
The flight was a scheduled domestic service from Bilbao to Madrid. While descending toward Madrid-Barajas Airport, the aircraft encountered severe weather including clouds, rain showers, and heavy turbulence. The aircraft was subjected to two significant downdrafts; the second caused a loss of approximately 800 meters in altitude within seconds, leading to an impact on the slopes of the Lobo-Cebollera peak, east of Somosierra. Despite the severity of the crash and the harsh winter conditions, 10 people (4 crew members and 6 passengers) survived the impact. One crew member managed to hike for help, leading to a relatively quick rescue operation by local teams who navigated deep snow to reach the site.
Final Conclusions
The accident was caused by the aircraft encountering severe downdrafts and turbulence while descending through the Somosierra mountain range in poor weather. These meteorological conditions caused a rapid loss of approximately 800 meters in altitude, leading to a controlled flight into terrain (CFIT) on the slopes of the Lobo-Cebollera peak.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
Bristol 170 Propulsion
Powered by two Bristol Hercules 672 radial engines, which provided the lift necessary for mountain crossings but were challenged by the severe downdrafts encountered during the flight.
Navigation Equipment
The aircraft relied on basic radio navigation aids of the era, which were susceptible to interference and reduced accuracy during heavy precipitation and mountainous terrain.
Interesting Facts
- 01The accident is one of the deadliest in the history of the Somosierra mountain pass.
- 02The Bristol 170 Freighter was a versatile aircraft often used by Aviaco for both passenger and cargo roles.
- 03Peña Cebollera, the crash site, marks the border between the provinces of Madrid, Guadalajara, and Segovia.
- 04Rescue teams had to navigate through deep snow and extreme cold to reach the wreckage.
Safety Actions & Advisories
Route Minimum Altitude Review
Following the accident, Spanish aviation authorities reviewed the minimum en route altitudes (MEA) for flights crossing the Central System to provide greater clearance from terrain during adverse weather.
Location
APPROXIMATE POSITION · Position recorded by the wikidata coordinate without a stated precision, so the ring shows roughly where the event occurred rather than an exact point. The ring shows the accuracy the record supports, not the point of impact.