Prop Feathered.He said wreckage of the right engine disclosed that it had been shut off and. feathered. jThe feathering operation takes | approximately eight seconds. During that time Col. Willard said, the terrific vibration apparently caused the transport’s right wing to tear off.The Denver-bound transport was flying at least 100 feet abovethe heavily-forested Sierra Nevada mountains along the airways radio beam when the crash occurred, Col. Willard said.The army’s version bore out the | story of Clair Heater, caretaker i of Hobart Mills,- the abandoned I lumber town near which the ! transport fragments crashed, who i watched the plane blow up.| Heater said one motor was still running after he heard an awful j ioud explosion” and then saw one j 1 wing of the airplane hurtle crazily j earthward. He had described how | the air was full of airplane i parts.”Smashes Fuselage The wing apparently hurtled against the right side of the plane, be continued, making the loud explosion ' noise which led several eyewitnesses to believe the planehad exploded.Impact of the wing against the fuselage apparently.caused 20 feet of the tail section to snap off, Cob i Willard said.j He said the result was that pieces of the plane probably flew jn all directions, which would lead ground observers to think the plane was disintegrating after a mid-air explosion.Searchers found the right wing and the feathered engine over g ridge more than three-fourths of a. mile from the area in which the