THERE HAS been a stunning development in the half-century-old mystery of what happened to a Truax Air Force Base F-89 Scorpion jet airplane that disappeared over Lake Superior on Nov. 23, 1953. The plane and its Madison-based crew - pilot Felix Moncla and radar observer Robert Wilson - were never found. The F-89 had been dispatched to track a large unidentified flying object that radar had spotted near the U.S.-Canadian border, and the plane's disappearance has been fodder for extraterrestrial theorists ever since. It now appears the missing plane has been located. Earlier this month, divers and engineers from the...