The Curtiss JN “Jenny” was a series of biplanes built by the Curtiss Aeroplane Company of Hammondsport, New York, later the Curtiss Aeroplane and Motor Company.
Although the Curtiss JN series was originally produced as a training aircraft for the US Army, the “Jenny” (the common nickname derived from “JN”) continued after World War I as a civil aircraft, as it became the “backbone of American postwar [civil] aviation”.
Curtiss combined the best features of the model J and model N trainers, built for the US Army and US Navy, and began producing the JN or “Jenny” series of aircraft in 1915.
Curtiss built only a limited number of the JN-1 and JN-2 biplanes.
The design was commissioned by Glenn Curtiss from Englishman Benjamin Douglas Thomas, formerly of the Sopwith Aviation Company.
The JN-2 was an equal-span biplane with ailerons controlled by a shoulder yoke in the aft cockpit.
It was deficient in performance, particularly climbing, because of excessive weight.
The improved JN-3 incorporated unequal spans with ailerons only on the upper wings, controlled by a wheel.
In addition, a foot bar was added to control the rudder.
The 1st Aero Squadron of the Aviation Section, US Signal Corps received eight JN-2s at San Diego in July 1915.
The squadron was transferred to Fort Sill, Oklahoma, in August to work with the Field Artillery School, during which one JN-2 crashed, resulting in a fatality.
The pilots of the squadron met with its commander, Capt. Benjamin Foulois, to advise that the JN-2 was unsafe because of low power, shoddy construction, lack of stability, and overly sensitive rudder.
Foulois and his executive officer Capt. Thomas D. Milling disagreed, and flights continued until a second JN-2 crashed in early September, resulting in the grounding of the six remaining JN-2s until mid-October.
When two new JN-3s were delivered, the grounded aircraft were then upgraded in accordance with the new design.
In March 1916, these eight JN-3s were deployed to Mexico for aerial observation during the Pancho Villa Expedition of 1916–1917.
After the successful deployment of the JN-3, Curtiss produced a development, known as the JN-4, with orders from both the US Army and an order in December 1916 from the Royal Flying Corps for a training aircraft to be based in Canada.
The Canadian version, the JN-4 (Canadian), also known as the “Canuck”, had some differences from the American version, including a lighter airframe, ailerons on both wings, a bigger and more rounded rudder, and differently shaped wings, stabilizer, and elevators.
As many as 12 JN-4 aircraft were fitted with an aftermarket Sikorsky wing by the then fledgling company in the late 1920s.
Variants
Although the first series of JN-4s were virtually identical to the JN-3, the JN-4 series was based on production orders from 1915 to 1919.
JN-1
Possibly unofficial designation of the second Model J, which served as the prototype for the Model JN.
JN-1W
Two aircraft that appear in US Navy records, which may have been confused with the Model S-4 and S-5.
JN-2
First production version, 8 built.
JN-3
Variant with new unequal-span wings and improved flight controls, 97 built for the RNAS (some sources indicate 91, but serial numbers total 97; 12 built in Canada) plus 2 for the US Army.
The six surviving JN-2s were modified to this standard.
JN-4A
Production version of the JN-4, 781 built
JN-4B
This version was powered by an OX-2 piston engine; 76 were built for the US Army, and nine for the US Navy.
JN-4C
Experimental version, only two were built.
JN-4 (Canadian) Canuck
Canadian-built version, 1,260 built by Canadian Aeroplanes Ltd for the RFC in Canada/RAF in Canada and USAAC: Independently derived from the JN-3, it had a lighter airframe, ailerons on both wings, a bigger and more rounded rudder, and differently shaped wings, stabilizer, and elevators.
Its use by the USAAC was curtailed as the lighter structure was claimed to cause more accidents than the US-built aircraft, although no air fatalities were attributed to the structural integrity of the type.
JN-4D
Improved version, adopting the control stick from the JN-4 (Canadian) 2,812 built
JN-4D-2
One prototype only, the engine mount was revised to eliminate the down thrust position.
JN-4H
Two-seat advanced trainer biplane with ailerons on both wings, 929 built for the US Army, notable for introducing the use of the Wright Aeronautical license-built Hispano-Suiza 8 V-8 engine for greater power and reliability.
JN-4HT
Two-seat, dual-control trainer version
JN-4HB
Bombing trainer version
JN-4HG
Gunnery trainer version
JN-4HM
Communications conversion of JN-4HT, powered by Wright-Hisso E 150-hp (112-kW), six converted, used to fly the first US Air Mail (May–August 1918)
JN-5H
Advanced trainer biplane, only one built
JN-6
Improved version of JN-5 trainer biplane series, notably used four ailerons, 1,035 built for the US Army and five for the US Navy
JN-6H
Improved version of the JN-6
JN-6BH
Bomber trainer version
JN-6HG-1
Two-seat, dual-control trainer version, 560 built from JN-6 production, 34 for US Navy
