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

After the move caused by the destruction after the tsunami, ltoh Hikoki Kenkyusho built its first aircraft under the designation Tsurubane No.1 (“crane wing”). Its design was started by Ito’s assistant, The Tsurubane’s design was the result of the retrieval of a 50 hp (37 kW) Gnome rotary engine from the crashed Tamai No.3 by a relative of Itoh’s talented assistant, Toyotaro Yamagata, and given to him to create his own aircraft. This engine was purchased by Yamagata’s uncle to allow his nephew to finish the project. Yamagata made some initial sketches but Itoh was asked to take on the detailed design.

The aircraft that emerged was a wooden-structured, fabric covered two bay biplane. Its wings were rectangular in plan, with bays separated by pairs of upright, parallel interplane struts. The considerable overhang of the upper, greater span, wing was wire braced and a cabane of parallel struts held the central upper wing high above the fuselage. As on Itoh’s earlier aircraft there were ailerons only on the upper wings, with chords that increased outwards.

Its rotary engine was shrouded with a standard, open-bottomed cowling intended to collect oil spray. Behind it the fuselage became slender and flat-sided, as with Itoh’s earlier designs. Its pilot had an open cockpit near the wing trailing edge. The tail was like that of the Itoh Emi 2 with the horizontal tail mounted on the top of the fuselage carrying elevators that had a cut-out for rudder movement. The fin and rudder had upright, parallel edges but a sloping top.

Though its landing gear was a conventional, single axle design, Itoh was aware of the need to make it robust. It had large wheels and was taller than those of his earlier landplanes, with landing legs and rearward drag struts doubly cross-braced.

The Tsurubane was completed on 8 May 1918 and flown soon after.

The Tsurubane No.1, like several other early Japanese civil aircraft, initially paid its way with demonstration flights. Yamagata began with flights around Hiroshima. These attracted support from the Asahi Shimbun newspaper resulting in a tour of Korea, at that time part of the Japanese empire, throughout November 1918. In the following spring the Tsurubane gave many exhibition flights in Osaka. World-wide, early aircraft demonstrators included risky tricks to swell audiences: on one occasion the Tsurubane carried a passenger astride the fuselage.

When it was retired from demonstration flights, the Tsurubane was used as a trainer by Itoh’s flying school. It is not known how long it remained airworthy but it was eventually privately purchased, then donated to the Aki-Itsukushima Shrine near Hiroshima.

Tsurubane No.1
Powerplant: 1 × Gnome, 37 kW (50 hp)
Propeller: 2-bladed
Wingspan: 10 m (32 ft 10 in)
Wing area: 30 m2 (320 sq ft)
Length: 6.5 m (21 ft 4 in)
Height: 2.6 m (8 ft 6 in)
Empty weight: 380 kg (838 lb)
Gross weight: 520 kg (1,146 lb)
Maximum speed: 80 km/h (50 mph, 43 kn)
Cruise speed: 65 km/h
Crew: one

After the destruction of Itoh’s hangar at Inage Beach by a tidal wave at the end of September 1917 his works and flying school moved to Tsudanuma Beach, otherwise known as Itoh Airfield. The move led a significant increase in student numbers and a new, two seat trainer was needed; until then they had relied on single-seaters. The solution was provided not by Itoh or his employees but by a regular visitor to the airfield, Tomotari Inagaki. He designed a simple and stable two seat trainer around the water-cooled 80 hp (60 kW) Hall-Scott V-8 engine taken from the Emi 3. It became known as the Itoh Emi 9.

The Emi 9, typical of its time, had a wooden frame and fabric covering. It was a straightforward two bay biplane, with two parallel pairs of interplane struts on each side. The wings were rectangular in plan and manufacture was further simplified by the absence of dihedral or stagger.

Its upright V-8 engine was installed in the nose with most of the upper part exposed and its rectangular radiator mounted edge-on just behind the engine on the fuselage port side. Pupil and instructor had separate open cockpits in a fuselage rather similar to that of the Emi 5. Its tail was with a triangular fin, a rudder with a straight leading edge which continued that of the fin and a deep, rounded trailing edge, though the control surfaces had horn balances, the first to be used on a Japanese civil aircraft.

The Emi 9 had a simple, single axle undercarriage with legs on the lower fuselage longerons and trailing drag struts to the fuselage centre line.

Built in 1918 the Emi 9 served the Itoh school as intended, though details of its history are lacking.

Powerplant: 1 × Hall-Scott, 60 kW (80 hp)
Propeller: 2-bladed
Wingspan: 9.80 m (32 ft 2 in)
Length: 7.45 m (24 ft 5 in)
Height: 2.30 m (7 ft 7 in)
Empty weight: 350 kg (772 lb)
Maximum speed: 111 km/h (69 mph, 60 kn)
Crew: one instructor
Capacity: one student

Though by around 1916 demonstration flights by early Japanese aircraft were beginning to be commercially viable, there were no suitable seaplanes. Otojiiro Otoh, who had designed and built Japan’s second commercial landplane, the Itoh Emi 1, was encouraged to fill the gap. The result was the Emi 3, completed in August 1917.

Like most aircraft of its time, it was a wooden-framed and fabric covered biplane. It was a two-bay design with wings braced by two pairs of parallel, vertical interplane struts on each side but, as the upper wing had a significantly longer span, there was also pairs of parallel, outward- leaning struts to brace the overhang. Only the upper wings carried ailerons.

Its water-cooled 80 hp (60 kW) Hall-Scott V-8 engine drove a two-bladed propeller. Close behind it there was an open cockpit for one passenger; the pilot’s cockpit was just aft of the upper wing trailing edge. The Emi 3’s fuselage was flat-sided and quite slender, with the horizontal tail mounted on its top. Its fin had a triangular profile and carried a rudder of roughly parallelogram profile.

It had twin floats, mounted with a pair of single struts to the fuselage forward and a transverse W-form strut to the fuselage and lower wing aft.

The Emi 3 was built at Itoh’s Inage Beach site and, assisted by Toyokichi Daiguchi and Toyotaro Yamagata, and with the help of student pilots, the aeroplane was completed in August 1917. Flight tests by several pilots found its performance, stability and handling were good.

Test flights over, the Emi 3 was taken by rail to Osaka. In preparation for demonstration flights, the Emi 3 Seaplane was assembled and maintained in a hangar located on the beach at Nishinomiya, just west of Osaka. Spectators’ fees made these flights a commercial success for Japan’s first passenger-carrying floatplane. Itoh named the only example Seagull (Kamome, かもめ).

Powerplant: 1 × Hall-Scott water-cooled V8, 60 kW (80 hp)
Propeller: 2-bladed wooden
Upper wingspan: 15.41 m (50 ft 7 in)
Wing area: 46.5 sq m (501 sq ft)
Length: 7.27 m (23 ft 10 in)
Height: 4.51 m (14 ft 10 in)
Empty weight: 580 kg (1,279 lb)
Maximum speed: 43kt (50mph)
Crew: one
Capacity: one passenger

By early 1917 Itoh had begun the design of a new aircraft. The Emi 2 owed much to its predecessor, both biplanes with wooden structures and fabric covering. Rectangular plan wings, shorter in span by 2.50 m (8.2 ft) and using a lower drag profile than before, were braced with pairs of parallel interplane struts, though the Emi 2, a two-bay biplane, had one less bay on each side. The Emi 2’s upper wing had a slightly greater span than the lower one, which had more rounded tips. The centre of the upper wing was supported over the fuselage by four parallel cabane struts. As on the Emi 1 there were ailerons, with chords which increased outwards, only on the upper wings.

The Emi 2 also inherited its predecessor’s engine, the 26–34 kW (35–46 hp) Grégoire Gyp. The flat-side fuselage had an open cockpit for the pilot; a semi-circular cut-out in the upper trailing edge increased the pilot’s upward field of view. The long span horizontal tail was roughly rectangular in plan and mounted on the upper fuselage and the vertical tail also was also parallel-sided, though with a sloping top.

The Emi 2’s wide track landing gear had two, rather than four wheels, each on a landing leg with bungee cord shock absorbers.

It flew for the first time in April 1917.

From May 1917 Itoh gave a series of demonstration flights from his east Inage Beach base, culminating in a visit to his home town of Osaka in September. His timing was fortunate, as his Inage Beach hangar was flattened by a typhoon-related tidal wave at the end of the month, while t Emi 2he was away. Demonstration flights resumed until the Emi 2 began use as a trainer from Itoh’s new base at Tsudanuma Beach.

Its last operations were under new owners based near Hammamatsu. It was again used for demonstration flights, piloted by the inexperienced Asao Fikunaga aound Osaka from August 1919. One flight took him to his home town of Toyonaka but the Emi 2 overturned on landing and was badly damaged. It was rapidly repaired but in May 1920, leaving Osaka, the aircraft hit a house roof, ending its career.

Powerplant: 1 × Grégoire Gyp, 26–34 kW (35–45 hp)
Propeller: 2-bladed
Maximum speed: 85 km/h (53 mph, 46 kn)
Wingspan: 9 m (29 ft 6 in)
Wing area: 25 m2 (270 sq ft)
Height: 2.25 m (7 ft 5 in)
Empty weight: 250 kg (551 lb)
Crew: one

By early 1915 Otijiro Itoh had established the Itoh Aeroplane Research Studio and an associated flying school and by that autumn had completed his first design, the Emi 1. The “Emi” was a respectful nod to the district of Osaka where he grew up.

The sole Emi 1 was a three-bay biplane with a fabric covered wooden structure. Its wings were of equal span and joined by parallel pairs of interplane struts. The upper wing was well above the fuselage and the lower ones mounted on the lower fuselage longerons. The Hyabusa-go’s French, 35–45 hp (26–34 kW) Grégoire Gyp four cylinder, water-cooled inline engine powered it. Its pilot had an open cockpit. At a time when there were few prepared airstrips, landing gear needed to be robust and the Emi 1’s gear had two wheels on each leg.

Its first flight was on 11 November 1915.

On 8 January 1916, not long after the first flight, Itoh flew the Emi 1 from his base at Inage Bay to Tokyo. This took 55 minutes and was the first flight to Tokyo. He later flew it to 58 Japanese cities, partly to advertise his aircraft and partly to raise air-mindedness in Japan. The Emi 1 was the second successful Japanese aircraft, following the Narahara 4 ”Ohtori-go”.

Later the Emi 1 was re-engined at Inage Bay with a 50 hp (37 kW) Hino Type, remaining in use with the flying school.

Emi 1
Powerplant: 1 × Grégoire Gyp 26–34 kW (35–45 hp)
Propeller: 2-bladed fixed-pitch
Wingspan: 11.50 m (37 ft 9 in)
Wing area: 33 m2 (360 sq ft)
Length: 6.65 m (21 ft 10 in)
Height: 2.50 m (8 ft 2 in)
Empty weight: 350 kg (772 lb)
Maximum speed: 76 km/h (47 mph, 41 kn)
Crew: one