Month in the Patent Office

An aircraft capable of horizontal flight as an aeroplane, and of vertical take off and descent, as well as vering, in the manner of a helicopter, consists of an ofoil‐shaped body 1 of approximately elliptical in form, having the major axis disposed trans‐sely and with a well portion 8 in which are mounted riable‐pitch contra‐propellers 7 driven by an engine the flow of air through the well being controlled louvres 10, 11 on the upper and lower surfaces pectively of the body 1. The axis of the propellers tilted forwardly at a small angle and transverse ide vanes 65 direct air from an inlet 9 into the spellers. When in horizontal flight the louvres 10, are closed and the propellers force the air rear‐rdly, while for vertical flight the louvres are ened so that the airflow through the body is ostantially vertical. In addition to the normal ntrol surfaces, rudder 13, elevators 16 and ailerons , the pitches of the propellers are capable of ferential adjustment to produce an unbalanced or torque to assist the rudder. When operating as a icoptcr additional control is provided by two pairs diametrically disposed segmental sliding covers , 19 which can be operated to close parts of the ening formed by the lower louvres 11.