Aeroflot Flight 4227 was a Tupolev Tu-154B-2 that was a domestic scheduled passenger flight from Alma-Ata Airport in Soviet Kazakhstan to Simferopol Airport in Soviet Ukraine on July 7, 1980. The aircraft reached an altitude of no more than 500 feet when the airspeed suddenly dropped because of thermal currents it encountered during the climb out, causing the airplane to stall before traveling 5 km (3.1 mi) away, crash and catch fire, killing all 153 passengers and 10 crew on board. To date, it retains the highest death toll of any aviation accident in Kazakhstan.
At the time of the accident Almaty was experiencing a heat wave. It was around 00:39 and Flight 4227 took off from Alma-Ata Airport in Soviet Kazakhstan. Only a few seconds after take off, the flight reached 500 feet. The weather was not on the flight's side; the plane reached a zone of hot air and then the Russian aircraft's airspeed dramatically dropped and the plane was caught in a big downdraft. The Tupolev stalled and plummeted, nose down, into a farm near the suburbs of Alma-Ata. It slid into a ravine, caught fire and disintegrated, killing everyone on board.
The soviet aviation board concluded that the crash was a result of Windshear, which caused a startling loss of airspeed, which then caused the Tupolev to stall and then entered a nose dive before crashing.