In 1918, the japanese Army purchased from France some of the most highly regarded military aeroplanes of the First World War, among them Nieuport 24 fighter. This and others were evaluated at the newly established Kagamigahara Army Airfield. At that time, 27 October, 1918, Tomotari Inagaki, a long-time friend of the company, and still studying in Tokyo Polytechnical School, became engineer of Itoh Aeroplane Research Studio. By chance, he had an opportunity to visit Kagamigahara and was able to rationalize the design and manufacture of a small aerobatic aircraft similar to the designs he had just seen. Beginning on 8 January, 1919, Inagaki started his first design as a company employee. It was to be a single-seat single bay biplane, light in weight, rugged, and easy to fly.
Logically, the design followed that of the Nieuport, but to obtain sufficient lift with the low powered 50hp Gnome engine Inagaki increased the total wing area, yet retained the same overall wing span and chord of the upper wing, by enlarging the lower wing to conform to that of an equal-span biplane rather than the sesquiplane arrangement of the Nieuport. The appearance of this aeroplane was considered radical when compared to other Japanese aircraft at that time.
The front half of the fuselage was ply-covered. To enhance the aeroplane’s appearance and resemble a fighter aircraft after which it was patterned, Itoh himself painted a white crane like a unit insignia on the sides of the fuselage similar to those often used by the French Air Force. This aeroplane was completed on 21 April, 1919, and made its first flight on 25 April.
Although Yamagata began teaching himself the skills of aerobatic flying, much had to be learned from an English-language book he had bought. His efforts included being suspended upside down while strapped in a chair to visualize control movements while in inverted flight. On 5 May, using this aeroplane, he became the first civil pilot in Japan to complete a loop.
Engine: Gnome, 50hp
Propeller: two-blade wood
Span: 7.21m (23ft 8in)
Wing area: 14.58sq m (156.942sq ft)
Length: 5.77m (18ft 11.25in)
Height: 2.38m (7ft 9.5in)
Empty weight: 204kg (450Ib)
Loaded weight: 340kg (749Ib)
Maximum speed: 74kt (85mph)
Climb to 1,000m (3,280ft): 4min 30 sec
All Aero 