Staff Writer (Updated: 8/5/2016):
The nickname of "Jenny" was formed from the "JN" used in the aircraft designation.
The JN-4 was born of a 1914 US Army requirement calling for a dedicated two-seat trainer aircraft platform to be powered by a single engine installation in a "puller" arrangement. The actual Curtiss JN-4 model owed much of its existence to the original Curtiss "Model J" and "Model N" airplane developments appearing prior; the Model J being a conventional biplane aircraft fitted with the Curtiss O series inline engine of 90 horsepower while the Model N series being completed with the Curtiss OXX inline engine of 100 horsepower. It was these two aircraft that would come to form the basis for the JN-1 mark to follow and this was, itself, followed by the limited-run JN-2 biplane form. The US Army Signal Corps purchased several JN-2s though these were eventually deemed unsafe after a fatal accident. The upcoming JN-3 was developed as an interim design and this sported unequal-span biplane wings with refined controls for the wing surfaces, quickly becoming the new JN standard for the preceding JN-2s. The design was furthered to become the definitive "JN-4" and it was this mark that would go on to make history for American military aviation. Its success was such that a modified, local-license production version in Canada - the JN-4 (Can) - was soon realized.
Design of the JN-4 was traditional for the time, characterized by its use of a staggered biplane wing arrangement of unequal span and parallel struts with a double-bay configuration. The engine was situated at the forward-most portion of the slim fuselage with twin inline cockpits (the front for the student and the rear for the instructor) fitted aft of the engine compartment and forward of amidships. When viewed in the side profile, the fuselage was something of a pleasing teardrop shape, running under the engine compartment to the base of the empennage tapering rearwards. The tail unit consisted of a rounded vertical tail fin and applicable horizontal tailplanes. Each pilot sat in an open-air cockpit protected by nothing more than a windscreen at the front. Visibility was therefore quite good from the sides and to the rear though the front was dominated by the engine placement and both positions suffered from the large biplane wing structure. The undercarriage consisted of a two-wheeled, reinforced arrangement of struts and cabling as well as a wooden tail skid under the tail unit. As the JN-4 was a dedicated trainer aircraft, she was not typically fitted with armament of any kind.