Claim: Aeroflot Flight 418, an international passenger flight operated by a Tupolev Tu-154A, figured in an accident (possibly caused by a radar failure) on June 1 1976.
Evidence: Aeroflot Flight 418 was an international passenger flight operated by a Tupolev Tu-154A, registered CCCP-85102, that was operating the second leg of an scheduled Luanda–Malabo–N'Djamena–Tripoli–Moscow passenger service. The plane crashed on into a mountain near Malabo Airport on Bioko Island, Equatorial Guinea on 1 June 1976. The cause of the accident could not be determined, but the investigation commission suspected a possible failure of the MSRP-12 radar on the aircraft may have led the crew to be unaware of their position. 
Aeroflot Flight 418 1 June 1976 (1976-06-01) Undetermined (possible radar failure) Tupolev Tu-154A