Was it stolen for parts or to make a flying bomb? How could a Boeing 727 just disappear without a trace? You might think in this age of satellite surveillance and sophisticated air-traffic controls, it would be near impossible for a jetliner to be stolen, flown away and not seen again for more than four months. Yet, that's just what has happened in a daring feat that has governments around the world fearing the jetliner may be in the hands of terrorists, just awaiting its final suicide mission. The story began May 25, when two men climbed aboard an idle...