Date & Time:
Jun 29, 1972 at 1037 LT
Type of aircraft:
De Havilland DHC-6 Twin Otter
Operator:
Registration:
N4043B
Flight Phase:
Landing (descent or approach)
Flight Type:
Scheduled Revenue Flight
Survivors:
No
Site:
Lake, Sea, Ocean, River
Schedule:
Chicago - Sheboygan - Appleton
MSN:
13
YOM:
1966
Flight number:
ZW671
Country:
United States of America
Region:
North America
Crew on board:
2
Crew fatalities:
2
Pax on board:
6
Pax fatalities:
6
Other fatalities:
0
Total fatalities:
8
Captain / Total hours on type:
3412
Copilot / Total hours on type:
1685
Aircraft flight hours:
15664
Circumstances:
Following a uneventful flight from Sheboygan, the crew started the descent to Appleton Airport in relative good weather conditions when, at an altitude of 2,500 feet, the Twin Otter collided with a North Central Airlines Convair CV-580 registered N90858. En route from Green Bay to Oshkosh, the Convair was carrying two passengers and three crew members. At the time of the accident, both airplanes were flying under VFR in an uncontrolled airspace. Following the collision, both aircraft crashed into Lake Winnebago, some five miles southeast of Appleton Airport. Debris were found floating on water, both airplanes were totally destroyed and all 13 occupants were killed.
Probable cause:
The failure of both flight crews to detect visually the other aircraft in sufficient time to initiate evasive action. the Board is unable to determine why each crew failed to see and avoid the other aircraft; however, the Board believes that the ability of both crews to detect the other aircraft in time to avoid a collision was reduced because of the atmospheric conditions and human visual limitations.
Final Report:
N4043B.pdf1.09 MB
