Month in the Patent Office

A rolling control system for a jet‐propelled aircraft consists of a pair of vanes 5 mounted diametrically opposite each other in the annular jet exhaust pipe 3 and rotatable in opposite directions by a motor 12 acting through gearing 10, 11 to give a spiral motion to the exhaust gases and thus set up a reaction rolling moment on the aircraft, thereby avoiding loss of control at low speeds. In their normal position the vanes act as flow straighteners for the turbine exhaust. As shown each vane extends across the full width of the exhaust pipe 3, but other constructions are described in which (a) it extends only across part of the pipe width; (b) the vane consists of a central movable portion mounted between fixed end portions; (c) the leading edge portion of the vane is fixed, the trailing edge being movable; (d) the whole vane is fixed, deflection of the exhaust being obtained by spoilers; (e) the vane is fixed, exhaust deflection being obtained by discharging pressure gas through apertures in the surface of the vane.