Aeroflot Flight 411

Aeroflot Flight 411

Company type	Scheduled international passenger flight
Industry	Aviation
Defunct	July 6, 1982 (1982-07-06)
Fate	Crashed after engine shutdowns and false fire warnings
Area served	Moscow to Freetown, Sierra Leone via Dakar, Senegal
Products	Passenger air transport

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Aeroflot Flight 411 was a scheduled international service operating from Sheremetyevo Airport in Moscow to Freetown, Sierra Leone, with an intermediate stop in Dakar in Senegal. Shortly after midnight on 6 July 1982, the four-engine Ilyushin Il-62 suffered a crash and was consumed by fire following the shutdown of two engines soon after departure. The accident resulted in the loss of all 90 passengers and crew aboard.

Aircraft

The aircraft involved was an Ilyushin Il-62M registered as SSSR-86513. Having first flown in November 1980, it had accumulated just over 4,800 flight hours before the accident occurred. The Il-62 is equipped with four jet engines arranged in pairs mounted on pylons alongside the rear fuselage.Template:Fix/category

Accident

At 00:33 local time, the airplane departed from Moscow's Sheremetyevo International Airport carrying 80 passengers and a crew of 10. Moments after takeoff, the warning system indicated a fire on engine No. 1, prompting the flight crew to shut down that engine and activate its fire suppression system. Within less than a minute, a similar fire warning for engine No. 2 was triggered, leading to its shutdown as well. The pilots initiated a return to Sheremetyevo Airport; however, at that point, the aircraft had reached an altitude of approximately 160 metres (520 ft) and was traveling at around 320 km/h (170 kn; 200 mph). Despite attempts by the crew to maintain control and altitude, the airplane gradually lost speed and height until it entered a stall roughly 75 metres (246 ft) above ground level. It subsequently crashed into a forested wetland area located about 1.5 kilometres (0.93 mi; 0.81 nmi) east of Mendeleyevo, Moscow Oblast and approximately 11.4 kilometres (7.1 mi; 6.2 nmi) northwest of Sheremetyevo Airport, less than three minutes after takeoff. Although one passenger originating from Sierra Leone initially survived both the impact and ensuing fire, this individual succumbed on the evening of 8 July.

Investigation

Following the accident, examination of the engines revealed no evidence of damage prior to impact nor any indications of an in-flight fire—the fire warnings were determined to be false. The fire warning system itself was extensively damaged by the crash and subsequent fire, preventing identification of the cause behind the erroneous alerts. Although there had been nine documented cases of bleed air leaks triggering false engine fire warnings on Il-62 aircraft between 1975 and the time of this incident, this possibility was excluded as a contributing factor.

The inquiry concluded that the aircraft could not sustain altitude on only two engines when configured with takeoff flaps and loaded at approximately 164,514 kilograms (362,691 lb), which neared the Il-62's maximum takeoff weight. No pilot error was found; the crew was unable to perform a forced landing due to darkness and the presence of populated areas beneath. Investigators confirmed that the pilots adhered to established flight manual procedures, yet noted that no guidance existed within the manual for handling the precise circumstances encountered during the event.