Investigation Summary
The investigation into Flight 1491 revealed that the aircraft broke apart at an altitude of approximately 1,700 meters (5,600 feet) during its descent. Investigators found that the lower wing panel, which is subjected to tension during flight, had developed fatigue cracks. These cracks originated in the lower spar cap of the wing center section. The failure was particularly insidious because the cracks were located in a region obscured by other structural elements, making them impossible to detect during standard visual maintenance inspections of the era without specialized non-destructive testing equipment. The failure was so sudden and complete that both wings separated from the fuselage almost simultaneously. The fuselage crashed into a forest near the village of Ruska Lozova, while the wings and engines were found at a significant distance from the main impact site.
Final Conclusions
The crash was caused by fatigue failure of the wing center section structure. Specifically, cracks had developed in the lower wing skin and stringers. This was determined to be a systemic issue with the An-10 design rather than an isolated maintenance lapse. Following the investigation, Aeroflot and the Soviet aviation authorities decided to retire the entire An-10 fleet from passenger service due to the risk of similar failures in other airframes.
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
Wing Center Section
The primary structural component connecting the wings to the fuselage; it failed due to fatigue cracking in the lower panels.
Lower Wing Skin Stringers
Internal structural reinforcements where the fatigue cracks originated, leading to the catastrophic loss of wing integrity.
Interesting Facts
- 01The aircraft had accumulated 15,483 flying hours and 11,105 flight cycles at the time of the crash.
- 02The breakup occurred while the aircraft was flying at approximately 1,700 meters (5,600 feet).
- 03Notable passengers included pop artist Viktor Chistyakov and the Deputy Prosecutor General of the USSR, Konstantin Mokichev.
- 04The wreckage was scattered over a wide area between the villages of Borshchevaya and Russkaya Lozovaya.
- 05The An 10 was permanently withdrawn from Aeroflot passenger service as a direct result of this accident.
Safety Actions & Advisories
Retirement of Antonov An-10
Following the discovery of systemic fatigue issues in the wing structure, the Soviet Union permanently grounded and retired the Antonov An-10 from passenger service in 1973.