R.Mikesh, A.Shorzoe Japanese Aircraft, 1910-1941 (Putnam)
Navy Yokosho Ro-go Ko-gata Reconnaissance Seaplane
During the First World War a number of Yokosho seaplane designs were created by Lieut Nakajima with the assistance of Lieut Kishichi Umakoshi, and there was much test flying associated with the improvement of these designs. Using foreign techniques, Umakoshi designed a reconnaissance seaplane with the emphasis on stability and control. The first prototype was completed in the autumn of 1917 and flight tests began in early 1918. Better performance was achieved with this aeroplane than with any previous japanese Navy aircraft.
Production began immediately at the Yokosuka Naval Arsenal and four aeroplanes were built in 1918. Confirming acceptance as a Navy type, they were officially designated Ro-go Ko-gata. Originally powered by a 140hp Salmson engine, the engine was soon changed to the newer 200hp Salmson, followed by the 200hp Mitsubishi type Hi (Hispano) engines which were used in production aircraft. The Ro-go Ko-gata was the first of the japanese Navy's aircraft to be put into production.
In April 1919 three of these aeroplanes were converted from two-seaters to single-seaters to increase their fuel capacity. In this configuration they made a record-breaking long-distance flight from Oppama, to Kure near Hiroshima, Chinhae (22 miles west of Pusan in Korea), Sasebo in western Kyushu, and return to Oppama. On this flight, Sub-Lieut Kanjo Akashiba set a record by flying from Sasebo to Oppama on 20 April, 1919, an indirect distance of 1,300km (808 sm) in 11 hr and 35min at an average speed of 61 kt.
The manufacture of these aircraft continued at Yokosuka Naval Arsenal until 1921. In 1920 production was begun by Aichi and Nakajima, making this the first Naval aeroplane built by Nakajima. In November 1923, to conform with a new Navy designation system for aircraft, the official Navy designation for these aeroplanes was changed to Yokosho-Type Reconnaissance Seaplane.
This first mass-produced aeroplane for the Navy was widely used together with the Hansa Reconnaissance Seaplane over the period 1921 to 1926.
In appreciation of his success, which began with the prototype design, Lieut Kishichi Umakoshi was given special recognition by the Minister of the Navy, the first for an aeroplane designer.
The entry into service of the Yokosho Ro-go Ko-gata, with its increased speed and manoeuvrability, made the Farman pusher seaplanes obsolete, and they were taken out of service. In time, a number of this newer type was released for civil use on such duties as mail carriage. Some were In service as late as 1928.
Single-engine twin-float biplane. Wooden structure with fabric covering. Rearward folding wings for stowage. Crew of two in open cockpit.
130-140hp Salmson M-9 (Type Sa) nine-cylinder water-cooled radial engine, driving a two-bladed wooden propeller (prototype); 200hp Salmson 2M-7 nine-cylinder water-cooled radial engine, driving a two-bladed wooden propeller (pre-production); 200-220hp Mitsubishi Type Hi (Hispano-Suiza E) eight-cylinder vee water-cooled engine, driving a two-bladed propeller (production).
One dorsal flexible 7.7mm machine-gun.
Span 15.53m (50ft 11 1/2in) 15.692m (51ft 6in)
Length 10.172m (33ft 4 1/2in) 10.16m (33ft 4in)
Height 3.68m (12ft 1in) 3.666m (12ft)
Wing area 48.22sq m 4.22sq m
(519.052sq ft) (519.052sq ft)
Empty weight 1,211 kg (2,669Ib) 1,070kg (2,358Ib)
Loaded weight 1,676kg (3,694Ib) 1,628kg (3,589Ib)
Wing loading 34.75kg/sq m 33.76kg/sq m
(7.1lb/sq ft) (6.9Ib/sq ft)
Power loading 12.9kg/hp (28.4Ib hp) 8.1kg/hp(17.8lb/hp)
Maximum speed 75kt (86.36mph) 4kt (96. 72mph)
Climb to 500m (1,640ft) 500m (1,640ft)
in 4min 12sec 4min
Range - 420nm (483sm)
Endurance - 5hr
218 built: thirty-two Yokosho (1917 to 1921) Type Sa and Type Hi engines, eighty Aichi (1920 to 1924) Type Hi engine and 106 Nakajima (1920 to 1924) Type Hi engine.