Patent ID: 8434710

Claim:
An aircraft comprising a fixed wing airframe equipped with a pair of contra-rotatable rotors positioned to provide forward thrust for wing-borne flight, both the collective and cyclic pitch of blades of said rotors being controllable in use; and structure by which the aircraft can stand on a ground with a chord direction of said wing and an axes of rotation of said rotors pointing upwards, wherein the aircraft is capable of vertical take off and landing and flight as a helicopter under lift produced by said rotors, capable of wing-borne flight under thrust produced by said rotors, and capable of transition between such helicopter and wing-borne flight without tilting of said rotor axes relative to said wing or tilting of said wing relative to the remainder of the airframe, said fixed wing includes a leading edge, a trailing edge and tips, and said rotors are mounted substantially at respective tips of said wing.