Date & Time:
Jun 19, 1957 at 1020 LT
Type of aircraft:
Douglas C-47 Skytrain (DC-3)
Operator:
Registration:
HB-IRK
Flight Phase:
Flight
Flight Type:
Training
Survivors:
No
Site:
Lake, Sea, Ocean, River
Schedule:
Zurich - Zurich
MSN:
20737
YOM:
1944
Country:
Switzerland
Region:
Europe
Crew on board:
9
Crew fatalities:
9
Pax on board:
0
Pax fatalities:
0
Other fatalities:
0
Total fatalities:
9
Circumstances:
The aircraft departed Zurich-Kloten at 0857LT on a local training flight, carrying one instructor, five student pilots, two engineers and one technician. The airplane followed different circuits at an altitude between 1,000 and 3,000 meters when control was lost over the Constance Lake. The aircraft went into a spin and crashed into the lake about 4 km off Romanshorn. The wreckage sank by a depth of 200 meters and only few debris were found on water and on the bank between Romanshorn and Arbon. All nine occupants have been killed.
Probable cause:
Thorough investigation of the wreckage revealed no evidence of any technical malfunction. On impact with the water the aircraft was in the following configuration:
- undercarriage fully extended; flaps retracted; trim position impossible to determine; right propeller not feathered; twin RPM indicator showed left engine - 1 550 RPM, right engine - 1 350 RPM.
The accident is attributed to the stalling of the aircraft following loss of airspeed, whereupon it unintentionally went into a spin. In view of insufficient altitude, it was not possible to level off the aircraft.
- undercarriage fully extended; flaps retracted; trim position impossible to determine; right propeller not feathered; twin RPM indicator showed left engine - 1 550 RPM, right engine - 1 350 RPM.
The accident is attributed to the stalling of the aircraft following loss of airspeed, whereupon it unintentionally went into a spin. In view of insufficient altitude, it was not possible to level off the aircraft.
Final Report:
HB-IRK.pdf1.62 MB
