Investigation Summary
The aircraft was operating the first leg of a multi-stop international flight from Luanda to Moscow Sheremetyevo, with scheduled stopovers in Malabo (Equatorial Guinea), N'Djamena (Chad), and Tripoli (Libya). The flight carried a diverse group of passengers, including 20 wounded Angolan soldiers traveling to the Soviet Union for medical treatment. The flight was conducted using a Tu-154A that had been manufactured only a year prior. While flying toward Malabo, the aircraft impacted a mountain at an elevation of approximately 750 meters (2,460 feet). The crash site was located on Mount San Carlos on the island of Bioko. Because the aircraft was relatively new and the crew was considered experienced, the sudden impact with terrain suggested a significant navigational error or equipment failure. Historical records contain conflicting data regarding the occupancy: while many sources cite 46 fatalities (36 passengers and 10 crew), others report 45 total deaths, and some Flight International records from the era listed a breakdown of 42 passengers and 4 crew members.
Final Conclusions
The official investigation commission could not reach a definitive conclusion regarding the cause of the crash. However, investigators suspected a failure of the onboard radar system. While some reports erroneously identified the failed system as the MSRP-12 (which is actually the flight data recorder), the Tu-154A was equipped with the Groza-154 weather and navigation radar. A failure of the Groza-154 would have deprived the crew of critical terrain awareness in the vicinity of the mountainous island, leading to the controlled flight into the side of Mount San Carlos.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
Groza-154 Radar
The primary weather and navigation radar system for the Tu-154. Investigators suspected its failure led to the crew's loss of terrain awareness, though some reports mistakenly referred to it by the flight recorder's designation, MSRP-12.
MSRP-12
The aircraft's flight data recorder system. It was mentioned in investigation summaries, likely due to a nomenclature error where it was confused with the radar system.
Interesting Facts
- 01The aircraft was nearly new, having been manufactured in 1975 at the Kuibyshev Aviation Plant.
- 02Among the 36 passengers were 20 wounded Angolan soldiers and several students.
- 03The crash occurred at an altitude of 750 meters (2,460 feet) on Mount San Carlos.
- 04The flight crew was described as experienced by Soviet aviation sources.
- 05The investigation suspected a failure of the onboard radar system, though some reports misidentified the system as the MSRP-12 (which is the flight data recorder).