The EC145 was a joint development between Eurocopter and Kawasaki Heavy Industries on the basis of their successful prior jointly produced BK 117 C1. Rather than pursuing an entirely clean sheet design, the forward cockpit and modern avionics of Eurocopter's EC 135 were adopted in combination with the proven BK 117's rear section; Flight International described the new helicopter, originally designed as BK 117 C2, as being "90% a combination of these two aircraft EC135 and BK 117 C1". However, there were significant areas of redesign, advantages held by the EC145 over its predecessor include possessing a greater range and payload capacity, a considerably increased and uninterrupted cabin area, reduced vibration and noise emissions, and measures to simplify maintenance and minimise operational costs. The noise signature of the EC145 is reportedly 60% lower than that of the BK 117 C1.