PHOENIX: Rescuers are trying to make their way through fresh snow to the possible site of a crash of a missing Air Force military jet. Ever since Captain Craig Button's A-10 attack jet broke formation and disappeared over the Colorado mountains last week, loaded with 450-pound bombs, speculation has had it that the 32- year old pilot might have stolen the plane. New reports from skiers near New York mountain in the Rockies that they saw a black cloud and heard a loud noise are fueling rumors that the plane crashed there. The Air Force theory that the plane went off-course because Button put the plane on autopilot doesn't hold up, critics say, citing evidence showing the jet changed course near the last point it was sighted -- an impossibility if the plane was on automatic. TIME's Mark Thompson says the plane's course does not necessarily support the theory of an aircraft heist. "Air Force people are saying the plane's circular motion could have been due to the fact that the plane only had about 90 seconds worth of fuel left. And since the plane has two engines, it's highly unlikely they both would have cut out simultaneously. In other words, one engine could have provided the thrust to force the plane in a circular direction." This scenario, combined with the fact that skiers near Vail heard a loud explosion at about the time the aircraft vanished from radar screens, makes the possibility that Captain Button stole the plane more remote. But the theory won't go away until search and rescue crews come up with the hard evidence, a difficult task considering the four feet of new snow that has buried the entire region.