Thursday, 17th of March, 1960

– United States of America

Northwest Orient Airlines Flight 710, a domestic scheduled passenger flight form Chicago-Midway Airport, Illinois (MDW/KMDW), to Miami International Airport, Florida (MIA/KMIA), operated with a Lockheed L-188C Electra, registration N121US, suffered an in-flight disintegration over Tobin Township, near Cannelton, Indiana.

The aircraft was completely destroyed. The six crew members and 57 passengers perished. (63 fatalities)

The crash of Flight 710 is the 46th deadliest aviation accident on U.S soil (It was the sixth deadliest at the time). It is also the eighth worst accident involving the Lockheed L-188.

– Details:

Electra N121US was operating on Northwest Flight 710 from Minneapolis (MSP) to Chicago (MDW) and Miami (MIA). The flight departed Minneapolis at 12:51 and arrived at Midway at 13:55. During the short time the aircraft was on the ground at Chicago, approximately 30 minutes, it was refueled and prepared for continuation of the flight to Miami. The flight departed Chicago at 14:38. At 14:45, the flight reported to the Indianapolis, Indiana, ARTC Center over Milford at 18,000 feet and estimating Scotland, Indiana, at 15:12. At 15:13, Flight 710 reported over Scotland maintaining 18,000 feet and estimating Bowling Green, Kentucky, at 15:35. This was the last radio contact with the flight.

At 15:25 the outboard engines and engine support structures, the complete right wing, and the outer portions of the left wing and ailerons separated in flight. The aircraft crashed out of control.

– Cause:

“The Board determines that tho 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.”