Date & Time:
Dec 23, 1973 at 2208 LT
Type of aircraft:
Tupolev TU-124
Operator:
Registration:
CCCP-45044
Flight Phase:
Takeoff (climb)
Flight Type:
Scheduled Revenue Flight
Survivors:
No
Site:
Plain, Valley
Schedule:
Lviv - Kiev - Kuybyshev
MSN:
3351104
YOM:
1963
Flight number:
SU5398
Country:
Ukraine
Region:
Europe
Crew on board:
6
Crew fatalities:
6
Pax on board:
11
Pax fatalities:
11
Other fatalities:
0
Total fatalities:
17
Aircraft flight hours:
13476
Aircraft flight cycles:
10942
Circumstances:
Following a night takeoff from Lviv-Snilow Airport, while climbing, the crew encountered a major technical failure on the left engine that caught fire. The airplane went out of control and crashed in a huge explosion in Vinniki, about 12 km east of the airfield. The aircraft disintegrated on impact and all 17 occupants have been killed.
Probable cause:
It was determined that a turbine blade located on the 1st stage of the high pressure turbine of the left engine broke off shortly after rotation, due to conception failure. Analyses revealed that the turbine blade that failed had not been the subject of a standard thermic treatment, which had the effect of reducing its resistance and its hardness that was lower than the requirements of the technical specifications. Investigators stated that the turbine blade failure caused a sudden loss of power of the left engine and several debris smashed in the turbine chamber, resulting in the rupture of a fuel line. Under pressure, the fuel leaked into the chamber and ignited while contacting various elements whose temperature was high. Under such circumstances, the flight crew was unable to maintain an adequate control of the aircraft.
