Date & Time:
Mar 17, 1960 at 1525 LT
Type of aircraft:
Lockheed L-188 Electra
Operator:
Registration:
N121US
Flight Phase:
Flight
Flight Type:
Scheduled Revenue Flight
Survivors:
No
Site:
Plain, Valley
Schedule:
Minneapolis – Chicago – Miami
MSN:
1057
YOM:
1959
Flight number:
NW710
Country:
United States of America
Region:
North America
Crew on board:
6
Crew fatalities:
6
Pax on board:
57
Pax fatalities:
57
Other fatalities:
0
Total fatalities:
63
Captain / Total hours on type:
254
Copilot / Total hours on type:
200
Aircraft flight hours:
1786
Circumstances:
The four engine aircraft departed Chicago-Midway at 1438LT bound for Miami, carrying 57 passengers and a crew of six. While cruising at an altitude of 18,000 feet over the south of Indiana State, the aircraft entered a dive and crashed in a huge explosion in a snow covered field located east of Tell City. Some debris were also found in a wooded area. The aircraft disintegrated on impact and all 63 occupants were killed. The crew was unable to send any distress call prior to the accident.
Probable cause:
The Board determines that the probable cause of this accident was the separation of the right wing in flight due to flutter induced by oscillations of the outboard nacelles. Contributing factors were a reduced stiffness of the structure and the entry of the aircraft into an area of severe clear air turbulence.
Final Report:
N121US.pdf1.84 MB
