The pilot of the DeHavilland DH-82A stated that shortly after takeoff he heard a loud bang over the engine noise and through the headset, followed immediately by severe vibration which increased until he reduced the power from take off to low cruise. The airplane was about 100 feet in the air and very near the end of the runway when the trouble started. The pilot elected to try to continue the climb and return to the field as quickly as possible. He was able to maintain sufficient airspeed while he turned around and lined up with the runway. Before he made the runway, the engine, though still running, felt like it stopped providing any thrust. The airplane was no longer able to maintain altitude and touched down in a pasture just before the runway. What appeared from the air to be a relatively smooth pasture; however, the terrain was rough and the impact sheared the landing gear. The left wing buckled as it settled to the ground. The pilot estimated that the total time from lift off to touchdown was approximate 2 to 3 minutes. The responding FAA inspector stated that examination of the engine revealed no discrepancies with it and its components. The wooden propeller was destroyed, split to the hub section. The propeller brass tip cap separated which started the initial vibration and tearing the propeller apart; consistent with the pilot’s account of having engine power but no thrust. The missing sections of the propeller were never located.