The year 1985 was an important milestone in the annals of European helicopters. The first was BK 117 certified. It had been developed jointly by a German manufacturer (MBB) and a Japanese company (Kawasaki). MBB was responsible for the rotors, tail boom, hydraulic systems, flight controls and stabilizer, whereas Kawasaki developed the landing gear, fuselage and transmission systems, including the main gearbox. Single-sourcing was employed in the manufacture of the BK117: the components were produced by a single supplier and shipped to the production centers in Germany (Donauwörth) and Japan (Gifu).
The BK 117 made its maiden flight at Ottobrun on 13 June 1979 with Siegfried Hoffman piloting, and the first Japanese machine lifted off on 10 August of the same year. The BK 117 had a rigid rotor made of titanium.
The helicopter's main success was to penetrate the market for emergency medical services, particularly in the United States. Of the 130 orders received when the helicopter was launched in February 1982, half came from US customers. The key to this success was chiefly its design, which was derived from the Bo105. The BK 117 had an exceptionally roomy cabin - more than 3.2 cubic meters – making it ideal for transport operations.
In the late 1990s, a series of modifications and advances were embodied in the BK117 to meet the requirements of the French Government for a rescue helicopter. Named the BK117 C2, the new advanced version was later to be rebaptized EC145.