Cause 3: UFO Over Soo Locks

The primary origin for this account in historical documents resides within Keyhoe's book "The Flying Saucer Conspiracy". Keyhoe wrote how he first heard about the mysterious disappearance:

"My first word on this mystery came from an old friend in Detroit, a former Army Air Corps navigator I'd met in earlier days, when I was aide to Colonel Charles A. Lindbergh. The night the jet vanished, he called me at my home near Alexandria, Virginia.

'This may be just a wild story,' he said, 'but there is a rumor out at Selfridge Field that an F-89 from Kimross was hit by a flying saucer. All I know is the plane is missing. You think there could be any truth in the UFO angle?'"

Over the course of the following days and weeks, Keyhoe pursues the lead. His primary source in the Air Force is First Lieutenant Robert C. White, who was serving as a Public Information Officer (PIO) at the Air Force Press Desk in the Pentagon.

In response to Keyhoe's questions, White confirms that the plane is missing and says about its fate "Its obvious. They had engine trouble and crashed in the lake." Keyhoe asked White why the F-89 was over the lake and is told that the F-89 was on an intercept mission, "checking on an unknown".

Keyhoe then asked White if the crew of the F-89 identified the unknown and White:

"I'm not sure. Let me call you back later."

The following day, Keyhoe flies to Des Moines, Iowa. After Keyhoe returns from his trip, he calls White at the Pentagon and is told that the unknown was a Canadian DC-3 which was "over the locks by mistake".

Keyhoe later tries to seek further information on the DC-3:

"'Well, did the F-89 actually intercept the DC-3, so that the Canadians had to identify themselves?'

'I'm not sure. That’s a classified Air Defense report. But we're certain the DC-3 was over the locks.'

'Then what was the other unknown – the object GCI said was 70 miles off Keweenaw Point?'

'Maybe another plane, we just don't know.'"

According to White, the USAF had sent the F-89 up to intercept an unknown which was observed in restricted air space over Soo Locks, between Sault Ste. Marie, Michigan and Sault Ste. Marie, Ontario. He wasn't certain if the F-89 had actually intercepted the craft which was over the locks. It is not clear from White's statements if he thought the F-89 had been chasing the same target when it disappeared over the Lake. This seems to indicate that the Air Force itself was perhaps having difficulties trying to determine what had happened to the F-89.