Unknown
1958-DEC-04 · La Rodilla de la Mujer Muerta, La Losa, Province of Segovia, Guadarrama Mountains, Spain

Aviaco — Flight Unknown

On December 4, 1958, an Aviaco SNCASE Languedoc crashed into the Guadarrama Mountains while en route from Vigo to Madrid, killing all 21 people on board. The aircraft was flying in severe winter weather conditions, including fog, snow, and icing. Investigators concluded that the pilot likely descended below the safe flight level to escape icing conditions, possibly under the mistaken belief that the aircraft had already cleared the mountain divide. The aircraft struck the peak of La Rodilla de la Mujer Muerta at an elevation of 1,999 meters, approximately 800 meters below its assigned flight level.

Aircraft
SNCASE SE.161 Languedoc
Registration
EC-ANR
Phase
Cause
Souls on Board
21
Fatalities
21
Origin → Dest
Vigo Airport (VGO) → Madrid-Barajas Airport (MAD)
Report

Investigation Summary

The flight departed Vigo at 15:40 local time, cleared for Instrument Flight Rules (IFR) at Flight Level 95. During the transit, the crew reported that their VHF radio equipment was out of order and requested the Barajas Tower to stand by on a high-frequency (HF) channel. At 17:10, Madrid Control cleared the aircraft to proceed directly to the Barajas radio range while maintaining FL95. The final communication occurred at 17:15 when the aircraft was authorized to switch frequencies to contact the tower. Shortly thereafter, the aircraft impacted the mountain and burst into flames. Search efforts were significantly delayed by torrential rain, high winds, and heavy snow in the rugged terrain. The investigation highlighted that while a flight 40 minutes earlier had reported only light icing, conditions had likely deteriorated rapidly into severe icing that could render the Languedoc's mechanical de-icing equipment ineffective.

Final Conclusions

The investigation concluded the accident was a result of controlled flight into terrain (CFIT) precipitated by severe icing. The captain likely initiated a descent to reach warmer air below the freezing level (estimated at 2,200 meters) to shed ice, but did so before safely clearing the mountain range. Contributing factors included severe turbulence, potential downdrafts on the lee slope of the mountains, and a possible navigational error regarding the aircraft's exact position relative to the mountain divide.

Video Analysis

No video analysis linked for this case file yet.

Systems & Failure Modes

i

Mechanical De-icing Equipment

The aircraft was equipped with mechanical de-icers which the investigation noted were practically inoperative under conditions of sudden, severe icing.

i

VHF Radio

The Very High Frequency radio system failed during the flight, forcing the crew to communicate via 3023.5 kc/s HF frequency.

Interesting Facts

  • 01The aircraft was a French-built SNCASE SE.161 Languedoc manufactured in 1946 (msn 28).
  • 02All 21 occupants, consisting of 16 passengers and 5 crew members, perished in the crash.
  • 03The crash site was located at an altitude of 1,999 meters, which was roughly 800 meters below the assigned altitude of Flight Level 95.
  • 04Search and rescue operations were severely hampered by fog, snow, and torrential rain.

Safety Actions & Advisories

Operational Limitations of Mechanical De-icing

Source ↗

The investigation highlighted that mechanical de-icing equipment on the Languedoc was insufficient for sudden, severe icing conditions. Pilots were cautioned that such systems might become inoperative in extreme weather, necessitating early tactical descents or route changes before ice accumulation becomes critical.

Location

La Rodilla de la Mujer Muerta, La Losa, Province of Segovia, Guadarrama Mountains, Spain · 40.7944, -4.1197

Case File History

  1. CorrectionUpdated safety actions.
  2. New evidenceUpdated findings.

Related Cases

Case ID · aviaco-languedoc-1958Last updated · Filed

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