N6770X - 1961 Aircraft Aircraft Registration

The pilot's failure to promptly feather the left propeller upon the initial loss of engine power shortly after takeoff and his failure to maintain airspeed while maneuvering with one engine inoperative, which resulted in a loss of control at a low altitude. Also causal was the partial loss of left engine power during initial climb for reasons that could not be determined because examination of the airplane did not reveal any evidence of mechanical malfunction that would have precluded normal operation.