Investigation Summary
The flight from Madrid was uneventful until the final approach to Vigo. The crew was cleared for a VOR approach to runway 20 in conditions of limited visibility due to fog. Investigation data revealed that approximately 10 seconds before impact, the aircraft began descending below the established glide path. The Ground Proximity Warning System (GPWS) issued a total of six aural warnings, including a 'Glide Slope' alarm at 125 feet, a 'Sink Rate' alarm at 60 feet, and finally a 'Whoop, whoop, pull up' command 2 seconds before impact. The crew failed to respond to any of these warnings. Investigators determined that the pilots likely experienced spatial disorientation; as they transitioned from instrument to visual references in the fog, they may have misinterpreted the approach lights as the runway itself. This 'visual capture' led them to ignore aural warnings and increase their descent rate to over 1,000 feet per minute in the final seconds, rather than maintaining a stabilized approach or executing a go-around when visibility was lost.
Final Conclusions
The Comision De Investigacion De Accidentes De Aviacion Civil (CIAAC) concluded the cause was the crew's violation of company procedures by increasing the descent rate in reduced visibility without a clear view of the runway. The crew failed to maintain a stabilized approach and ignored multiple GPWS aural warnings, likely due to a high cognitive workload and focus on visual acquisition of the runway.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
José Luis López Hernández, aged 44.
First Officer
Aged 45.
Flight Inspector
Aged 44.
Systems & Failure Modes
GPWS
The Ground Proximity Warning System issued a total of six aural warnings (including Glide Slope, Sink Rate, and Pull Up alerts) which were recorded but not acted upon by the crew.
Approach Lighting System
The aircraft's left wing and landing gear struck elevated lighting structures located short of the runway threshold (reported as 115 meters by CIAAC/Wikipedia and 100 meters by BAAA).
Interesting Facts
- 01All 110 passengers and 6 crew members survived the accident; 62 occupants were injured, 3 of them severely.
- 02The aircraft was a 19-year-old DC-9-32 nicknamed Juan Ponce de Leon.
- 03The post-crash fire was fed by fuel escaping from a ruptured right wing fuel tank.
- 04The descent rate reached an average of 1,035 feet per minute just before impact.
- 05Fire services arrived at the wreckage within one minute of the alarm being raised.
- 06The accident occurred at 20:17 local time in conditions of thick fog.
Safety Actions & Advisories
Sterile Cockpit Rule Enforcement
Recommended that the sterile cockpit rule be strictly applied up until an altitude of 10,000 feet, requiring the crew to engage only in discussions relevant to the flight.
GPWS Training
Recommended enhanced crew training specifically for responding to GPWS alerts in emergency scenarios.
Audio Recording Standards
Recommended the installation of flight recorders with better audio quality and easier data retrieval.
Approach Procedure Monitoring
Recommended that airline operators closely monitor the procedures for instrument approaches to the runway.