 Single-point pressure refueling is also provided, expediting turnarounds.De Havilland Canada builds the LJ45's wings, and Bombardier subsidiary Short Brothers of Belfast, Northern Ireland, builds the fuselage and empennage.The Learjet 45XR is an upgraded version of the Model 45, introduced in June 2004, offering substantially higher takeoff weights, faster cruise speeds and faster time-to-climb rates than the Model 45, chiefly through modifications to the engine.