GEN YANAGISAWA ENGINEERING SYSTEM CO LTD
Mr Yanagisawa, whose nickname is 'Gen', developed a small, but comparatively high-powered, horizontally opposed two-cylinder engine while working for the Zenoa company. By 1985, this had been tested in a hang-glider, para-glider and model aircraft, but failed to find a market. Tests of a coaxial rotor RPV in 1987 were unsuccessful because of control problems, while a manned twin-engined design in 1992 failed to produce sufficient lift. By 1994, however, this had evolved into the BDH-1 (Boy's Dream Helicopter 1), exhibited at that year's Japan Aerospace Show. A three-engined BDH-2 followed in 1996 and was further modified as the BDH-3 which, although successful, was unable to sustain height with one engine inoperative. The BDH-4 was shown at AirVenture, Oshkosh, USA, in 1997 and continues to be refined. Manufacture is by ESCO, a general engineering company headed by Mr Yanagisawa, which has produced over 400 types of equipment since being founded in 1971. The assistance of a US agent was enlisted to collaborate on H-4 trials, such as ballistic parachutes and high-speed cruising, which are prohibited by Japanese air law.