R.Mikesh, A.Shorzoe Japanese Aircraft, 1910-1941 (Putnam)

Army-built Aeroplanes by the Provisional Military Balloon Research Association (Rinji Gunyo Kikyu Kenkyu Kai), and Army Arsenals (Rikugun Kosho)

   The formation and the background of this first source for Japanese built military aircraft, the Provisional Military Balloon Research Association (PMBRA), has been described in some detail at the beginning of this work. Its origin stemmed from the Imperial Order No.207 that was issued on 30 July, 1909, in that it was to develop new weapons systems, particularly those that pertained to balloons and aeroplanes for their military application along with associated air-to-ground communications.
   Making up this organization were fourteen members from the Army, Navy, Tokyo Imperial University, and the Central Meteorological Observatory. While this was intended to be bipartisan between the two military services, it was determined by Army influence in that Army Lt-Gen Gaishi Nagaoka was appointed the first president, with Col Jiro Inoue a manager, and having their offices at the 7th Division Army Headquarters. These efforts resulted in aircraft that were developed or purchased of which some were put into Army service, while the Navy accepted none of the design. This may well have been because of Army-Navy distrust, for each had its separate development group that fed on findings made by the PMBRA.
   The manufacture of these PMBRA aircraft that were identified as Kaishiki (Association Type) aeroplanes continued until 1916. During this period, officers of the PMBRA supervised modifications of imported Maurice Farmans and the manufacture of some of these took place at the Tokyo Army Artillery Arsenal. New designs that came from the PMBRA were normally built with the joint effort of the PMBRA's Tokorozawa Factory and the Tokyo Army Artillery Arsenal. As aeroplane manufacturing became more technologically orientated, the Nagoya Army Ordnance Arsenal was used for the repair and manufacture of the Type Mo-4 aircraft, and of later types.
   In April 1919, the PMBRA was abolished and replaced by the Army Aviation School of the newly formed Army Department of Aviation. Aeroplanes emerging as a result of this organization were known as Koshiki (School Type) aircraft, instead of by their former designation of Kaishiki. The actual building of these aircraft that had been done by the Tokorozawa Factory was then taken over by the Tokorozawa Branch, Department of Supply, under the Army Department of Aviation. Simultaneously, the research and design of new aeroplanes was absorbed by the Department of Research of the Tokorozawa Army Aviation School.
   During the Army's final phase of aircraft manufacture, the Chikusa Army Machinery & Equipment Manufacturing Works produced aero engines, while airframes were manufactured at the Atsura Army Weapon Manufacturing Works of the Nagoya Army Ordnance Arsenal. With the formation of the Army Air Headquarters on 1 May, 1925, the manufacture of aircraft by the Army was terminated. By this time the design and manufacture of new aeroplanes was undertaken through competition among civilian companies.
   The descriptions of aircraft that follow will identify those that were built under the auspices of the Army production. Resources used in the development and building of aircraft were exclusively those of the Army that centred on the PMBRA facility at Tokorozawa, west of Tokyo, and Army arsenals in Tokyo and Nagoya.


Kaishiki No.1 Aeroplane

   In 1911, Capt Yoshitoshi Tokugawa, an Army committee member of the PMBRA, designed and supervised the construction of the first Japanese-manufactured military aeroplane. This work took place at the Army Balloon Corps facility at Nakano Village, west of Shinjuku, Tokyo.
   Using as a pattern, the Henri Farman of 1910 that had been imported, design began in April 1911 and construction was started the following July. Assistant Engineer Goichi Nakazato supervised the construction, while others assisting were Privates l/c Gisaburo Ohshima, Kichitaro Sugiyama and Jinzo Hirano, along with a carpenter and ten soldiers. Although the engine and the propeller were imported from France, all other materials were procured in Japan. The airframe was mainly constructed of hinoki (Japanese cypress) and covering was two layers of silk glued together by what was described as liquid rubber. Attachment fittings, bracing wires and turn buckles were specially procured from iron works companies or bought from local hardware shops.
   While this was regarded as a Farman-type, it did have its unique differences. It was converted to a sesquiplane design, giving it reduced wing area and therefore increased speed. A change was made to the aerofoil by having a greater frontal curve in the hope of achieving better lift. Ailerons were on the upper wing only, and the tail was simplified by having a single horizontal tail surface. The engine and propeller were mounted higher than in the original design, and therefore the undercarriage could be shortened. A windshield was added for the pilot.
   When completed, in October 1911, it was known as the Tokugawa Type aeroplane, but later was given the official identity Kaishiki No.1 Aeroplane. The aeroplane was moved to the Army facility and flying field at Tokorozawa where it made its first flight on 13 October, piloted by Capt Tokugawa.
   The flight recorded on 25 October, 1911, indicated that the aeroplane reached an altitude of 50m (164ft) and attained a speed of 72km/h (45mph). Maximum height recorded was 85m (278ft) and distance covered was 1,600m (1 mile). As tests continued it was discovered that the propeller ground clearance was too small, causing the propeller blades to make contact with the grass and reducing its rotation speed and resultant power. After modifying this and other necessary changes, the aeroplane was known as the Kaizo Kaishiki No.1, Kaizo signifying modified.
   Changes to the structure included lengthening the undercarriage, and fitting landing skids not integral with the airframe structure so that they could be more easily replaced when broken. The twin rudders were replaced by a single and larger-area rudder to take better advantage of the propeller slipstream for improved directional control. Longer interplane struts gave a greater spacing between the two wings, and the windshield was removed to give the student pilot a better sense of speed, thought at that time to be essential.
   A controversy developed over which aeroplane was the first Japanese-made aeroplane to fly successfully: this Kaishiki No.1 or the civilian Narahara No.2. The problem was that after a straight flight of 60m at a height of 4m, the undercarriage of the Narahara aircraft had failed on landing after its flight on 5 May, 1911, at Tokorozawa, five months before the Army-built craft was flown. Was the flight a failure or a success when the undercarriage broke upon landing? (see Narahara No.2 Aeroplane)
   The following data are for the original Kaishiki No.1 aeroplane.

   Single-engine pusher sesquiplane trainer. Wooden structure with fabric covering. Elevators at nose and tail. Skid-type undercarriage with dual wheels. Open tandem seating.
   50hp Gnome Omega seven-cylinder air-cooled rotary engine, driving a Chauviere two-blade wooden propeller.
   Span (upper) 10.50m (34ft 5 1/2in), (lower) 8m (26ft 3in); length 11.50m (37ft 8 1/2in); height 3.90m (12ft 9 1/2in); wing area 41sq m (441.334sq ft).
   Empty weight 450kg (992Ib); loaded weight 550kg (1,212Ib); wing loading 13.4kg/sq m (2.7Ib/sq ft); power loading 11kg/hp (24.2Ib/hp).
   Maximum speed 39kt (45mph); endurance 3 hr.
   One built in 1911, modified in 1912.


Kaishiki Nos. 2, 3 and 4 Aeroplanes

   With confidence gained by the success of the Kaishiki No.1, the PMBRA began construction of the Kaishiki No.2 in March 1912. Like the first, this was designed by Capt Tokugawa. It was built in the hangar at Tokorozawa Flight Test Grounds, and first flown in June 1912 by Tokugawa.
   Similar designs completed in November 1912 were the No.3 and No.4. Basically, the No.2 was like the No.1 but had a longer undercarriage for better propeller ground clearance. Some changes were made in the interplane strut configuration, and the tailplane and rear elevator were enlarged to improve stability. Engines varied with these aeroplanes and they were often interchanged. Since they were pusher aeroplanes, the engine arrangement with a 50hp Gnome rotary had the propeller between the engine mounting and the engine; but the No.4 powered by a 50hp Anzani rotary engine had its propeller behind the engine.
   In May 1912, with training aircraft now available, the Army selected five officers to become the first class of pilot officers. The next month, six officers were selected for the first reconnaissance-observer course. The importance of aviation within the Army was being recognized. To further demonstrate the capability of the aeroplane at this time, the first flight to visit Tokyo
was made on 27 October, 1912, by the Kaishiki No.2. To make this long flight of about 18 miles, the removable windscreen nacelle was reinstalled, and Capt Tokugawa made this historic flight, starting at 05:58 and landing at the Yoyogi Parade Grounds at 07:45. It was from here, twenty-two months before, that Tokugawa had made the first flight in Japan on 19 December, 1910, in an imported Farman. After refuelling, he circled the major boroughs of Tokyo and landed once again at Yoyogi for fuel. Returning to Tokorozawa, his starting point, he had covered 96.5km (60sm), a major accomplishment at that time.
   These early 'Tokugawa-type' aircraft, as they were more popularly called, were entered in many exhibitions, both singly and together, receiving considerable press coverage. Since the military was the greatest motivator in developing the aeroplane in Japan, and with its intended use as a military weapon, it must be noted that the Army used the Kaishiki No.4 to demonstrate for the first time, in December 1913, the dropping of simulated bombs.

   Single-engine pusher sesquiplane trainer. Wooden open structure with fabric-covered wings and control surfaces. Elevators at nose and tail. Skid-type undercarriage with two sets of dual wheels. Two seats in tandem.
   50hp Gnome Omega seven-cylinder air-cooled rotary engine, driving a Chauviere two-bladed wooden propeller (No.2 and No.3). 60hp Anzani six-cylinder air-cooled rotary engine, driving a fixed-pitch two-bladed wooden propeller (No.3 after modification and No.4).
   Span 11 m (36ft); length 11 m (36ft); height 3.90m (12ft 9 1/2in); wing area 41sq m (441.334sq ft).
   Empty weight 450kg (992Ib); loaded weight 570kg (1,256Ib); wing loading 13.4kg/sq m (2.74lb/sq ft); power loading 11kg/hp (24.2Ib/hp).
   Maximum speed 39kt (45mph); endurance 3hr.
   Three built, No.2, No.3 and No.4, all in 1912.


Kaishiki No.5 and No.6 Aeroplanes

   Following the arrival of the four Maurice Farman 1913 aircraft from France, the manufacture in Japan of No.5 and No.6 was put under the two officers who had studied in France and purchased the aeroplanes, Lt Kenjiro Nagasawa and Lt Shigeru Sawada. The aircraft were built from the same drawings but one was constructed at the PMBRA at Tokorazawa and the other at the Artillery Arsenal in Tokyo. Both were powered by 70hp Gnome rotary engines, experimentally manufactured at the Artillery Arsenal, but they proved less reliable than the 70hp Renault engines, thus ending the production of the Gnome-type after only two engines had been built.
   The two aeroplanes were a combination of designs for the Kaishiki No.3 and No.4 airframe and Maurice Farman 1913 wings. They were completed in the autumn of 1913 and entered operational service with the Type Mo 1913 Aeroplanes. Compared to the four preceding imported models, the two new aeroplanes had more powerful engines, making them faster by 2. 7kt, larger fuel capacity for a duration of four hours, and the seats were located in a longer fuselage nacelle to improve visibility for aerial reconnaissance. Within the PMBRA, the two aeroplanes were unofficially called Kaishiki Second Year Model (Second year of Taisho; 1913).

   Single-engine pusher sesquiplane trainer with crew nacelle. Wooden structure with fabric covering. Elevators at nose and tail. Skid-type undercarriage with dual wheels. Crew of two in open cockpit.
   70hp Gnome seven-cylinder aircooled rotary engine, driving a Rapid-santral two-bladed wooden propeller.
   Span 15.50m (50ft 10 1/4in); length 11m (36ft 1in); height 3.66m (12ft); wing area 44.1 sq m (474. 7sq ft).
   Empty weight 485kg( 1,069Ib); loaded weight 765kg (1,686Ib); wing loading 12.7kg/sq m (2.6lb/sq ft); power loading 10.9kg/hp (24Ib/hp).
   Maximum speed 51 kt (59mph); endurance 4hr.
   One each of No.5 and No.6 built in 1913.