209,137. Whiteside, H. A. Sept. 4, 1922. Aeroplanes; helicopters; propelling; steering and regulating altitude; planes, construction and arrangement of and connecting together.-An aeroplane is fitted with lifting-propellers 9, 10 which can be tilted to exert a forward or backward effort, and the sustaining-plane adjacent to the propellers is provided with panels 40, 40<1>, Fig. 4, which can be turned into a vertical position to diminish the resistance to vertical motion. The propellershafts 11, 12 are driven through bevel-gear from a transverse hollow shaft passing through sleeves 17, 17<1> to a gear box 24 where it is connected by bevel gear to a vertical shaft 29 connected to the motor. The shafts 11, 12 are mounted in gear boxes 13, 13<1> carried by the sleeves 17, 17<1> which are connected together by arms 20, 20<1> and a rod 21. A toothed quadrant on the sleeve 17<1> is enclosed in a casing 30 and is engaged by a worm on a shaft 33 to enable the casings 13, 13<1> to be turned and the propeller shafts tilted. Forward propulsion may be effected by a propeller 5, or solely by the propellers 9, 10 when forwardly tilted. To support the propellers and gearing, upper and lower main beams 35. 36 are braced by struts 37 and ties 38. Instead of a transverse shaft passing through the sleeves 17, 17<1> the propellers may be driven by inclined shafts leading to fixed gear-boxes adjacent to the gear casings 13, 13<1> which in this modification are connected together by a transverse rod spaced from their axis of rotation and moved by a worm quadrant pivoted about a parallel transverse rod connecting the two fixed gear boxes. The panels 40, 40<1> of the upper plane, Fig. 4, are pivoted about pintles 41, 42 placed nearer to the inner edge than to the outer edge of each panel so that they tend to close under air pressure. Projections 53 on their outer edges engage the framework of the plane when in their closed position. The pintles 42 extend into a hollow beam 43, which may be the front spar of the plane, and carry pinions 47 engaged by racks on transverse rods 44. 45. The rods 44, 45, which are on opposite sides of the centre of the plane, are connected by links to a lever 49 on a central vertical shaft 50 which can be turned to varying degrees by a lever in the cockpit. A modified machine is described having two single supporting-surfaces arranged in tandem, each surface having two tiltable lifting-propellers at its front edge.