Crash of a Douglas C-47B-1-DL off Romanshorn: 9 killed

Date & Time: Jun 19, 1957 at 1020 LT
Operator:
Registration:
HB-IRK
Flight Phase:
Flight Type:
Survivors:
No
Schedule:
Zurich - Zurich
MSN:
20737
YOM:
1944
Country:
Region:
Crew on board:
9
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
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.
Final Report:

Crash of a De Havilland DH.85 Leopard Moth in Zurich: 3 killed

Date & Time: Mar 13, 1957
Operator:
Registration:
HB-OKO
Flight Type:
Survivors:
No
MSN:
7105
YOM:
1935
Country:
Region:
Crew on board:
1
Crew fatalities:
Pax on board:
2
Pax fatalities:
Other fatalities:
Total fatalities:
3
Circumstances:
Crashed on landing at Zurich-Kloten Airport, killing all three occupants, among them the pilot Walter Nägeli.

Crash of an Ilyushin II-12B in Eglisau: 23 killed

Date & Time: Nov 24, 1956 at 1820 LT
Type of aircraft:
Operator:
Registration:
OK-DBP
Flight Phase:
Survivors:
No
Schedule:
Zurich – Prague
MSN:
9 301 35 17
YOM:
1949
Flight number:
OK548
Location:
Country:
Region:
Crew on board:
5
Crew fatalities:
Pax on board:
18
Pax fatalities:
Other fatalities:
Total fatalities:
23
Circumstances:
After takeoff from Zurich-Kloten Airport, while climbing by night, the airplane went out of control and crashed nose first in a field located in Eglisau, about 12 km north of the airport. The aircraft disintegrated on impact and all 23 occupants have been killed. A crater of 10 meters width and three meters depth was found at the point of impact.
Probable cause:
The exact cause of the loss of control could not be determined with certainty.