243,693. Barling, W. H. Nov. 28, 1924, [Convention date]. Aeroplanes; planes, arrangement and construction of; propelling; tanks, arrangement of. -A large biplane aeroplane has its planes built upon central girders of open hollow formation and covered at the top with sheet metal and underneath with fabric which is removable for inspection and repair. The sheet metal is corrugated with the ribs running in the direction of flight, and the fuselage covering is similarly corrugated. The lower plane contains the engines and tanks. Fig. 8 shows a section of the lower plane in which the main girder member is built up from corrugated metal to form a hollow member open at the bottom, the vertical sides being loaded by horizontal members as shown to bring the neutral axis approximately to the geometrical centre of the section. The open end is braced by struts 15<1> and cross wires, and the vertical sides are strengthened at intervals by vertical angle members. Formers 33 preserve the cross-section of the girder and additional formers 34, 35 preserve the contour of the front and rear portions of the plane. The upper surface is covered with corrugated sheet metal 36, and portions 38, 39 of the under-surface at the front and rear are also covered with sheet metal. The lower fabric covering is stitched to a network of wires 40 extending between transverse wires 41, 42, the wire 41 being secured to a series of hooks in the part 39 and the wire 42 being anchored to fastenings 45 provided with straining-bolts 46 passed through a leading edge member 37. The network 40 is secured to hooks 44 depending from the. central girder. The upper plane is similarly constructed but the front straining bolts for the lower fabric covering do not pass through the leading edge, and the fabric is sewn from the outside to the girder formers after being placed into position. The metal portions of the underneath coverings may be plain or corrugated. The upper plane is secured to the fuselage by convergent struts 5, 6, Fig. 4, secured to the girder structure at points within the plane, and the two halves of the lower plane are secure'd at 76, Fig. 3, to parts 4, projecting from the fuselage. The upper and lower planes are secured together by struts 9, 10, 13, 14 in W-formation, the vertical struts and the lower ends of the struts 9, 10 being secured to the sides of the girder members in the neutral plane and the upper ends of the struts 9, 10 being secured at 12 to a member 72, Fig. 3, which distributes the stress over a large portion of the girder. Bracing wires 16, 17, 7, 8 are employed. To correct any tendency to dip sideways owing to any lack of symmetry developed during construction, the lower planes are fitted with hinged sections 77 which can be set at any angle by bolt connections. The planes have removable wing tips 98, 99, Fig. 3. Each lower wing contains three engines 47, 48, 49 with parallel shafts leading into a common gear box 50 from which a vertical shaft passes through a streamlined standard to drive a propeller 55. The tanks 56, 57, Fig. 8, are mounted upon trays 60 supported by stays 61 from a girder 58 which extends the length of the wing through the formers 33 and is secured to a corresponding girder passing through the fuselage. Radiators 115, Fig. 3, of arched form partially screen the landing carriages. Fuselages and nacelles are formed with longitudinally corrugated metal coverings built up from sheets. Where the corrugations meet the joints between adjacent sheets at an angle, flanges are formed, keeping the corrugations the full depth, and adjacent flanges are riveted together. Framework.-The formers 33, 34, 35 and the girder 58 are each formed in two halves with outwardly-bulged portions so that when riveted together they form tubular booms and bracings as shown at 58, Fig. 8. Land wheels and skids; shock-absorbers, applications of.-An axle 107 carrying two wheels 109, Fig. 3, is supported from the wing girder by tripod struts 104, 106 and by V-struts in the plane of flight. A fairing from the radiator 115 partially encloses this structure. A forwardly extending strut 110 connects the wheel axle to a forward pair of wheels and the forward end of the strut is supported by a telescopic strut embodying an oil dash-pot. A tail skid is connected by a pair of hinged struts to the fuselage and by a telescopic strut connected to a stress distributing member in the fuselage. Wing-tip skids 93, are similarly mounted beneath the lower wings. Aerostats.-According to the Specification as open to inspection under Sect. 91 (3) (a) the upper portions of lighter-than-a.ir craft are covered with sheet metal. This subject-matter does not appear in the Specification as accepted.