R.Mikesh, A.Shorzoe Japanese Aircraft, 1910-1941 (Putnam)
Born on 14 August, 1877, at Zaimoku-cho, Kanazawa City, Ishikawa Prefecture, Onokichi Isobe developed his interest in aviation around 1908 when he was the chief engineer of the third reserve ship Anekawa as a Lieut-Cdr in the japanese Navy. While stationed aboard this ship, he designed and built a small glider equipped with floats that he would drop, with ballast, from the ship to alight on the water. Since this worked successfully, he then attempted to tow the model behind a torpedo-boat but this ended in failure.
At his request, Isobe was reassigned to the first reserve ship Otoha (formerly a cruiser) with home port at Yokosuka. On this assignment, his senior officer was Cdr Odagiri, an officer who shared his interest in aeronautical theory and gave Isobe encouragement and assistance.
Onokichi Isobe designed and built a Henri Farman type seaplane with help from seamen stationed at, and materials acquired from, the Yokosuka Naval Engineering School. A most noticeable feature of this biplane design was the use of a single-interplane strut instead of the conventional two parallel struts. This was accomplished by using bracing-wires to prevent vertical twisting of the wing on the single strut. It was a seaplane glider at first, equipped with a pair of inflatable rubber-lined canvas floats made for him by the Meiji Rubber Co in Shinagawa, Tokyo. For this combined design, he applied for a patent on 8 April, 1910, which was granted on 16 November of that year (No.18825) as the Isobe Aeroplane.
When used as a two-seat glider, it was launched on the water at Shirahama beach, at Yokosuka, on 19 April, 1910. After confirming its stability while afloat, Isobe then had it towed by a steamboat at a speed of approximately 18 knots. The glider became airborne to a height of about 3m and flew for approximately 60m. At that point the glider went out of control and hit the water, wingtip first. Although this test ended in failure, it proved that an aeroplane could take off from and alight on the water in this fashion. It was to be another year before imported aircraft would be flown by the Navy for the first time from the Naval facility at Oppama. It is assumed that this Isobe aircraft was eventually repaired and had an engine installed.
Isobe No.2 Aeroplane
With this taste of success, Isobe began immediately to build his second man-carrying aircraft. As soon as the airframe was completed, he asked the Provisional Military Balloon Research Association to let him borrow an engine for his new aeroplane. This request from outside the PMBRA was granted reluctantly, for the members looked upon Isobe's work as that of an amateur and unauthorized. It was with the help of Dr Aikichi Tanakadate that assistance was granted. (see Iga Maitsuro-go Aeroplane for details of Tanakadate)
A number of taxi-ing tests were made at Shirahama beach, but when Admiral Sotokichi Uryu, Commander of Yokosuka Naval Station, was there, Isobe attempted to fly the aeroplane, but at the point of take off, the nose dug into the water and the aircraft turned over due to a design flaw in the control system and was severely damaged. Isobe planned to build a No.3 Aeroplane to correct the flaws that were suspected, but with his personal funds already exhausted, he was forced to abandon further plans. He left the Navy on 1 December, 1911, at age 33.
Single-engine tractor biplane seaplane with fore and aft stabilizers. Wooden structure with fabric-covered wings and empennage. Pilot seated in open structure.
25hp Anzani three-cylinder fan-type air-cooled engine, driving a two-bladed wooden propeller.
Span 8m (26ft 3in); length 8.30m (27ft 2 3/4in); height 2.70m (8ft 10 1/4in).
Empty weight 410kg (903Ib).
One built in April 1910.