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

CURTISS J

   The Model J was the first Curtiss tractor design after the Model G, and the preliminary design was undertaken in England when Glenn Curtiss hired B. Douglas Thomas from Avro. The original version of the J delivered to the Army (number 29, illustrated) had equal span wings with ailerons on both and the landing gear shown. A modified version (30) had a shorter lower wing, ailerons on the upper only, and deleted the skids. No. 30 developed into the JN-1 while 10 production JN-2s (41/50) with modified landing gear evolved from No. 29. Model J (Number 29): Span, 40 ft. 2 in.; length, 26 ft. 4 in.; gross weight, 1,345 lb.; high speed, 84 m.p.h.

O.Thetford British Naval Aircraft since 1912 (Putnam)

CURTISS JN-3

   The JN-3 was the forerunner of the more famous JN-4 Jenny trainer, and six (Nos. 1362 to 1367) were ordered for the RNAS in 1914; deliveries followed in March 1915. A further 79 (Nos.3345 to 3423) were produced to Admiralty orders by the parent firm and 12 (Nos.8392 to 8403) by Curtiss (Canada) at Toronto. All were fitted with the 90 hp Curtiss OX-5 engine.

K.Molson, H.Taylor Canadian Aircraft since 1909 (Putnam)

Curtiss JN-3

   The Curtiss Aeroplanes & Motors Co had been formed at Toronto with the intention of making training aircraft for the Curtiss Aviation School at Toronto and for the Royal Naval Air Service (RNAS). Production of the current Curtiss model, the JN-3, got under way in May 1915 but then the Curtiss Canada was given priority, which delayed production of the first and only batch of JN-3s.
   The Curtiss JN aircraft family got its start by combining some of the best features of the Models J and N which resulted in the Model JN. This was then developed into the JN-2 which grew into the JN-3 and which in turn developed into the familiar JN-4 series of trainers. In the spring of 1915 the JN-3 was just entering production in the United States for the RNAS.
   The JN-3 was an unequal-span biplane of quite conventional wire-braced wooden construction and was fabric covered. All machines made for the RNAS and the Curtiss Aviation School at Long Branch, Ontario, had Deperdussin controls fitted, but the US Signal Corps aircraft had shoulder yoke controls.
   A batch of 18 aircraft was laid down at Toronto, 12 for the RNAS and six for the Curtiss Aviation School. This was the first series production of aircraft undertaken in Canada. One or two aircraft were completed before the Curtiss Canada, and the balance completed as a group after the Canada had left the shop in August 1915. The Canadian prototype JN-3, RNAS 8392, was first flown at Long Branch on 14 July, 1915, by Anthony H. Jannus.
   Some of the RNAS machines were recorded as being at Hendon on 1 November, 1915. Probably all were shipped there but it is possible that 8394 may have gone directly to Killingholme air station. Flt Lt Sydney Pickles did most, if not all, of the acceptance flights and they were later assigned to RNAS stations at Chingford, Detling, Eastchurch and Killingholme. One aircraft, 8403, has been reported as being transferred to the French Government.
   Some of the Canadian-built JN-3s were modified in Britain for various reasons. A number of strengthening modifications were recommended as a result of tests conducted on a US-built machine in the summer of 1915. Four-bladed propellers of British manufacture were frequently installed.
   The Curtiss Aviation School machines continued to serve there until the School closed towards the end of 1916. Some modifications were introduced. The diagonal tube from the bottom of the front centre-section strut to the top of the rear centre-section strut, which severely restricted access to the front cockpit, was replaced by a system of wires. Also it seems that one or more of the JN-3s at Long Branch may have had ailerons on the lower wings as later used on the JN-4 (Canadian) prototype.
   When Canadian Aeroplanes took over the Curtiss company in December 1916 and the RFC (Canada) began its training operations, the School’s JN-3s were not purchased, but were transferred to the Curtiss School at Newport News, Virginia, which had been set up in December 1915 by Capt Thomas Scott Baldwin. At least one aircraft, Curtiss Aviation School’s No. 8, remained at Long Branch until sometime in January 1917 and Bertrand Acosta used it to take Frank W. Baillie (later Sir Frank). President of Canadian Aeroplanes, for his first flight.

   One 90 hp Curtiss OX. Span, upper 43 ft 10 in (13-36 m) approx, lower 33 ft 11 1/4 in (10-34 m); length 27ft 2 1/2 in (8-29 m); height 9ft 11 in (3-02 m); wing area 360sqft (33-5sqm) approx. Empty weight 1.300lb (590kg);* loaded weight 1,918lb (871kg).* Maximum speed 72-9 mph (117-3km/h);* climb 3.000ft (914m) in 9min 10sec.*

*Figures for a US-built JN-3, RNAS 3348. tested in England on 30 July, 1915. Canadian-built JN-3s should have been the same.

Журнал Flight

Flight, December 11, 1914.

AEROPLANE TYPES,
THE CURTISS TRACTOR BIPLANES.

   FOR some time past the Curtiss Co. of Hammondsport, NA., have been experimenting with tractor biplanes - a type that has only just recently come into favour in the U.S.A. - and have as a result of their experience turned out some machines that compare very favourably with European practice. These have given very satisfactory results, and several have already been delivered to the U.S. Government. Two or three different types of these Curtiss "model J" tractors have been manufactured, but they only differ in dimensions and details. The model shown in the accompanying sketch-plan and elevation is a two-seater reconnaissance type with pilot and passenger seated in tandem. The planes are similar in construction to those employed on the Curtiss flying boats, but having a different wing section. They are of one-piece construction, with main spars of I section ash, hand-grooved and shaped. The ribs are built up of spruce, and all the important joints are copper bound, whilst the whole frame-work is strongly braced with piano wire internally and with stranded cable for the interplane bracing. The planes are covered with unbleached linen doped with Curtiss oil and water proof dope. Large ailerons, measuring 10 ft. by 2 ft, are hinged to the rear spars of the top plane, which has a greater span than the lower. Top and bottom planes are separated by two pairs of laminated spruce struts on either side of the fuselage, and in the centre by four struts forming extensions of the fuselage struts. The interplane struts are mounted in quick detachable fittings bolted to the spars. The planes are perfectly straight: that is, they have no dihedral angle, but the top plane is slightly staggered forward.
   The fuselage is of rectangular section tapering to a vertical knife-edge at the rear, and with a turtle-back extending behind the pilot's seat. It is built up of ash longerons and nine sets of ash and spruce struts joined by steel clamps in such a manner that the longerons are not pierced. Cross bracing is by steel wire and Binet turn-buckles, which permit easy adjusting for the necessary rigidity. Mounted in the nose of the fuselage, on a laminated ash and spruce bed, is the 90 h.p. 8-cyl. V water-cooled Curtiss OX engine, immediately in front of which is the radiator. The whole of the engine is enclosed by a Duralumin bonnet, in the sides of which are louvres. The front of the engine bed is bolted to the fuselage nose plate, to which are anchored the longerons. At the rear the engine bed is supported by a hard wood cross member connected to the second vertical pair of fuselage struts, which are made extra strong for the purpose. Coupled direct to the engine is an 8ft. Curtiss tractor screw. Just behind the engine is the passenger's cockpit, and behind the latter, at the rear of the main planes, is the pilot's, both being protected by streamline cowels. Dual controls are provided, either of the Curtiss shoulder-yoke type or Deperdussin pattern. The maximum depth and width - at the cockpits - of the fuselage is 2 ft. 11 ins. and 2 ft. 2 ins. respectively.
   The tail consists of a semi-circular stabilising plane, to the trailing edge of which are hinged two elevator flaps, mounted on the top longerons of the fuselage, and a partly balanced vertical rudder pivoted to the last strut of the fuselage. This strut is also extended below the latter in order to carry a sprung tail skid. The chassis consists of two skids 6 ft. long, attached to the lower longerons of the fuselage by three pairs of struts each. Sprung to the skids by means of rubber bands is a tubular steel axle carrying a pair of disc wheels. The principal dimensions of this machine are as follows :- Span, upper plane, 40 ft. 2 ins.; lower, 30 ft.; chord, 5 ft.; area of main planes, 346 sq. ft.; area of stabilising plane, 30 sq. ft.; area of elevator, 16 sq. ft.; area of rudder, 7 sq. ft.; overall length, 26 ft. 4 ins.; speed range, 45-75 m.p.h.; climbing speed, 400 ft. per min.
   Another model made is a scout, which differs from the model just described in that the main planes have a span of 24 ft. top and bottom, and that ailerons, 7 ft. by 2 ft., are fitted to both top and bottom planes. The chassis is also somewhat modified. This model has a speed range of 45 to 80 m.p.h. and a climbing speed of 500 ft. per minute. Both these models can be converted into hydro-biplanes for over-water flying by the fitting of a single pontoon float to the chassis in place of the wheels, and as such have been very successful.
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