This was attempted on 24 November 1971 by an unknown hijacker, widely known as D. B. Cooper, who jumped from a Boeing 727 along with US$200,000 in ransom money.[2] However, it is unknown if he survived the jump. Subsequently, a number of individuals carried out copycat hijackings against Boeing 727s and safely parachuted to the ground, although all were apprehended by the authorities. To prevent this, Boeing 727s were ordered to be fitted with a simple device known as a Cooper vane that prevented the ventral airstair from being opened in flight.[3]