What happened
A scheduled flight departing from Moscow-Sheremetyevo Airport for Freetown, via Dakar, experienced a critical emergency shortly after takeoff. Following departure from runway 24R, the crew retracted the landing gear. Within eight seconds, an alarm indicated a fire in engine number one. The crew followed established procedures to shut down the engine and activated the onboard fire suppression systems.
Approximately thirty seconds later, a second fire alarm activated for engine number two. The flight crew responded by shutting down the second engine and declaring an emergency. While attempting a right turn at a speed of 320 km/h and an altitude of 160 meters, the Ilyushin Il-86 struggled to maintain performance with the undercarriage retracted and flaps set to 30 degrees. The aircraft entered a high angle of attack, leading to a loss of airspeed and altitude.
At an altitude of roughly 75 meters, the plane stalled, banking left at a 70-degree angle before pitching down 20 degrees. The aircraft struck a forested area in Mendeleyevo, approximately 11.4 km northwest of the airport. The impact caused the aircraft to disintegrate, resulting in 90 fatalities.
Findings
Investigations revealed that the fire alarms for both engines were erroneous. The primary cause was identified as hot air escaping from a damaged air conditioning system pipe, which blew directly onto the temperature sensors, triggering the false fire indications.