P.Bowers Curtiss Aircraft 1907-1947 (Putnam)

Model G Tractor. The first Curtiss aeroplane designed as a tractor was the Model G, developed late in 1912 in response to US Army interest in the type. Two were built and sold to the Army in 1913.
   The first, which became Signal Corps No.21, was a side-by-side two-seater with a 75 hp Curtiss Model O engine driving a three-blade propeller through a chain reduction system. The aeroplane sat on a tricycle undercarriage and the unequal span swept-back wings used interplane ailerons. First flown at San Diego in February 1914, S.C.21 was accepted by the Army on 12 June after change to a direct-drive propeller, extended wing span, upper-wing ailerons, and conventional tailwheel undercarriage. Purchase price was $5,500. The Army later added floats for operation in Hawaii and sold the barely-adequate aeroplane out of the Service in mid-1914.
   The second G, Signal Corps No.22, was similar to S.C.21 except for 90 hp direct-drive OX engine, four-wheel undercarriage, and longer equal-span wings. It was accepted by the Army on 1 December, 1913, with shorter lower wings and upper-wing ailerons. Intended as a Service type, it too was inadequate and served as a trainer until condemned in October 1914.

   Model G
   Two seats.
   Span 41 ft (12,49 m); length 25 ft (7,62 m); wing area 390 sq ft (36,23 sq m).
   Gross weight 2,400 lb (1,088 kg).
   Maximum speed 53,5 mph (86 km/h).
   Powerplant 90 hp Curtiss OX.
   US Army serial numbers, 21, 22.

G.Swanborough, P.Bowers United States Military Aircraft Since 1909 (Putnam)

CURTISS G TRACTOR

   The two 1913 Curtiss Model Gs for the Army (21 and 22) were the first Curtiss tractor designs and the first Curtisses, other than flying boats, to use an enclosed fuselage or hull. The side-by-side two seaters differed considerably in detail, and the first, with a four-wheel landing gear, flew for a while with an uncovered fuselage and was fitted with a direct-drive 80 h.p. Curtiss OX engine (illustrated). The second had tricycle landing gear, enclosed fuselage, and a long dorsal fin. It also had chain reduction gearing to the three-blade propeller. Span, 38 ft. 4 in.; length, 24 ft.; gross weight (No. 22), 1,050 lb.; high speed, 75 m.p.h.; range, 315 miles.