Lake Michigan, 16 August 1965.
United Flight 389 flew from La Guardia NY en route to Chicago Center. The flight was westward and smooth at 35,000 feet. Clearance was obtained to O'Hare International.
All that remained was a 13 minute flight traversing Lake Michigan…
At 2120 hours, 9:20 PM, people on the shore reported seeing a fireball. It blasted up from the lake surface, eventually lighting up the whole eastern sky of Chicago.
All the bodies and most of the wreckage was recovered from the plane eventually, after 20 days of searching. In the first fews days thousands of pieces of floating wreckage had already been recovered.
The flight data recorder was not found.
Instead of the missing flight data recorder the NTSB and other investigators turned to NORAD and its SAGE (Semi-Automatic Ground Environment) system.
What SAGE showed was intriguing, to say the least…
SAGE had actually generated two sets of tracking data over Lake Michigan at the time of the United 389 disaster. These tracks were designated AO39 and KO47. AO39 seemed to be United 389, until two minutes before the crash. Then, a new telemetry data set was generated automatically on what was presumably United 389- this second track was KO47.
At two minutes before the crash, AO39 ceased and KO47 began. At this same time, United 389 had been meant to level off.
It didn't. Its descent continued… Towards the lake surface…
With only seconds remaining before death for himself and everyone on board, Captain Towle of United 389 was calmly talking in a relaxed manner to Chicago Approach Control about his altimeter setting. He was setting his altimeter, and apparently ignoring all the warning telltales that would have been directly before his eyes!
As for track KO47, it matched United 389, to within 200 feet of where the crashed aircraft was found.
The only problem is, track KO47 didn't stop at the time and place of the crash.
KO47 went on for another two minutes after the crash, for 20 nautical miles due west of the site of the impact. This would mean that KO47 underwent phenomenal acceleration from 390 miles per hour at the time of the crash to over Mach 1.
The ATC Group report remains classified secret.
