Design of the EC145 began with the BK 117C medium twin-engine helicopter. The BK 117 started in 1977 as a joint effort between MBB GMBH in Germany and Kawasaki Heavy Industries in Japan. Like its predecessor the BK 117 C-1, the new twin is being produced cooperatively with the Japanese firm, Kawasaki Heavy Industries (KHI).
The EC145 has a higher takeoff weight than the BK117. The seating capacity of the various configurations is for up to 10 persons, which includes the pilot and nine passengers. The length and width of the cabin has been extended compared to the BK117. The EC145 is an 8- to 11-place medium twin-engine turbine helicopter that is characterized by a large combined passenger cabin and luggage compartment that extends the full length of the fuselage. Clamshell doors at the back of the fuselage allow access to this combined passenger and luggage compartment. The standard seating configuration has a pilot and one passenger seat up front and two or three rows of three seats in the back. Alternatively, two litters can be loaded through the clamshell doors and placed side by side on the flat floor. In this configuration, there is also room for two or three medical attendants.
The drivetrain of the EC145 uses two Turbomeca Arriel 1E2 engines and a rigid, hingeless, four-bladed rotor based on the BO 105 design. The main rotor blades are made of composite construction, as are the two tail rotor blades. The tail rotor is mounted at the top of the vertical fin, which provides unobstructed access to the rear clamshell doors. The primary fuselage structure is constructed of aluminum alloy. Secondary fuselage structures are made of Kevlar and other composites.
The EC145's first flight was in June 1999, with certification following in 2000. The first customer delivery was made in April 2002.