What Caused the Alert?
The primary unanswered question that still seems clouded in mystery is what caused the alert at Kinross which resulted in the F-89's mission over Lake Superior?
There are three main possibilities which are referenced in the historical accounts.
According to the report documenting the USAF Official Accident Board's Investigation, the alert was caused by an RCAF C-47 flying 30 miles off course from its flight plan in an easterly direction over Lake Superior.
A second explanation is referred to in Donald Keyhoe's book "The Flying Saucer Conspiracy". According to the Keyhoe, a PIO (Public Information Officer) working at the Pentagon told him that the cause of the alert was "a Canadian DC-3" which was "over the locks by mistake".
The third explanation is the basis of Keyhoe's main storyline within his book, this being that the cause of the alert was not a DC-3 in restricted airspace over the locks at Sault Ste. Marie, but rather this was a UFO that was never identified.
