Crash of a Putilov Stal-3 in Novoarkhangelsk: 3 killed

Date & Time: Sep 1, 1938
Type of aircraft:
Operator:
Registration:
CCCP-L1260
Flight Phase:
Survivors:
No
Schedule:
Kiev - Odessa
MSN:
260
YOM:
1936
Country:
Region:
Crew on board:
2
Crew fatalities:
Pax on board:
1
Pax fatalities:
Other fatalities:
Total fatalities:
3
Circumstances:
The single engine airplane departed Kiev on a flight to Odessa, carrying one passenger and two crew members. About an hour and 27 minutes into the flight, while in cruising altitude, the aircraft was approaching an area of storm when the right wing suffered a structural failure and detached. The airplane entered an uncontrolled descent and crashed in a pasture. All three occupants were killed.
Probable cause:
The cause of the crash was an insufficient structural strength of the upper core of the fuselage frame n°3, which caused the frame to collapse under the conditions of flight in a pre-thunderstorm front and the subsequent collapse of the entire aircraft.
The following factors were identified:
- Insufficient strength of some elements of the airplane according to the conditions set by the strength standards of 1937,
- Failure of the design bureau of Plant n°81, which allowed the frame n°3 of the fuselage to have insufficient strength,
- Failure of the weather station at Kiev Airport, which did not indicate thunderstorm phenomena in the weather forecast for the Kiev - Odessa route, as it was according to the weather service sector in reality.