Episode 106 of "Without a Trace"
s05e12 Tail Spin

The team searches for an air traffic controller who vanishes after he almost let two planes collide on his watch. The team initially thinks that Rawlings may have disappeared because of things going on in his personal life -- the death of his wife and estrangement from his son. However, in the week prior to his disappearance, Rawlings reported a suspicious flight pattern of a Middle-Eastern pilot and he was threatened by someone at his home. Now, the agents try to determine whether the pilot may be involved in retaliating against Rawlings, or if there is a much bigger conspiracy in play.