P.Bowers Curtiss Aircraft 1907-1947 (Putnam)

Twin JN (Model 1B) - The Twin JN of April 1916, tentatively designated JN-5, was an enlargement of the new JN-4 model to a twin-engined type for observation work. Wing span was increased by use of an 11 ft 4 in (3,45 m) centre section for the upper wing and the installation of short panels between each lower wing and the fuselage. The standard JN-4 outer wing panels had one degree of dihedral outboard of the flat centre-sections on the prototype and 3 1/2 degrees on the production versions.
   The need for increased tail area was met by installing a Curtiss R-4 rudder and an enlarged fin on the prototype and a modified R-4 fin on the production versions. Directional control was still marginal but was improved somewhat by modifying the starboard Curtiss OXX-2 engine to rotate in the opposite direction to that in the port side unit as was done on earlier Curtiss twin-engined flying-boats.
   In spite of the two engines, the Twin JN was still only a two-seat machine and crew efficiency was greatly handicapped by the wide separation between the pilot's cockpit aft of the wing and the observer in the nose.
   The US Army acquired eight Twin JNs in 1916 and early 1917, seven by direct purchase and one a donation to the Militia by private citizens. These saw very brief service on the Mexican border in 1916. The US Navy acquired two examples, which were operated as twin-float seaplanes.
   One Army model, serial number 428, differed greatly from the other Twin JNs. It was so retrograde in both aerodynamic and structural detail that in the absence of other evidence the author believes it to be an entirely different and somewhat earlier aeroplane, possibly the rumoured 'Twin R'. Since its general configuration was similar to the Twin JN, Curtiss doubtless found it easier to sell this existing aeroplane to the Army as a modified Twin JN than as a new and entirely separate design.
   US Army serial numbers: 102/107,428,470 (delivery of 470 doubtful).
   US Navy serial numbers: A93, A198

Twin JN
   Reconnaissance aircraft. Pilot and observer. Two 90 hp Curtiss OXX-2.
   Span 52 ft 9 3/8 in (16,08 m) (upper), 43 ft 1 3/4 in (13,15 m)(lower); length 29 ft (8,83 m); height 10 ft 8 11/32 in (3,26 m): wing area 450,28 sq ft (41,83 sq m).
   Empty weight 2,030 lb (921 kg): gross weight 3,110 lb (1,411 kg).
   Maximum speed 80 mph (128,74 km/h); climb to 3,500 ft (1,067 m) 10 min: service ceiling 11,000 ft (3,353 m).
   One example had a Lewis machine-gun.

Twin R - Early in 1916 Curtiss converted an R-2 airframe to an experimental twin-engined type. No official designation is known beyond the reference to a 'twin-engine R'.