 Deliveries of this model began in November 2002 with the Hong Kong Government Flying Service becoming the first operator.In early 2003, Eurocopter completed studies for an even more powerful version of the EC155 B1, designed to better compete with new rotorcraft such as the AgustaWestland AW139 and to better meet military customer's requirements.Several major elements of the EC155, such its rotor system (albeit modified to operate at slower rotational speeds), were used in the Eurocopter X3, an experimental high-speed compound helicopter which set an unofficial speed record of in 2013.