Aeroflot Flight N-826

On Sunday 3 August 1969 an Antonov An-24 operating Aeroflot Flight N-826 (Рейс N-826 Аэрофлота Reys N-826 Aeroflota) crashed resulting in the death of all 55 people on board. An investigation revealed the cause of the accident was an in flight failure of the propeller attached to "No. 1" (left) engine, which caused an explosive decompression.

Accident

Flight N-826 was a scheduled passenger flight from Voroshilovgrad to Lviv, with stops at Dnipropetrovsk and Vinnytsia. At 15:47 (3:47 PM), the aircraft departed Dnipropetrovsk. At 15:58(3:58 PM), the crew reported an altitude of 3,600 meters (11,800 ft) and received permission from ATC to climb to 4200 m. This was the last radio transmission from Flight N-826. While climbing through 4,000 meters (around 13,100 ft), the No. 2 propeller blade of the left engine separated from its hub and punctured the fuselage, severing control cables for the stabilizer, ailerons, and rudder, rendering the aircraft uncontrollable. Because of the imbalance, the left propeller detached. The aircraft then banked left and entered a descent with its airspeed increasing. After a steep spiral, the airliner struck the ground at an angle of 45-50 degrees and at a speed of 500-550 km/h. At 16:06(4:06 PM), ATC tried to communicate with Flight N-826, but received no answer. All further attempts at communication with the An-24 were unsuccessful.