STONY POINT ‒ Fifty years ago, on Dec. 1, 1974, Northwest Orient Airline Flight 6231 disappeared from JFK Airport’s radar somewhere over Harriman State Park. A report from JFK was sent to police.

It's a Northwest mystery that has never been solved. A man who called himself "Dan Cooper" paid cash for a one-way ticket to Seattle at the Northwest Orient Airlines counter at the Portland ...