The modifications that converted the Learjet Model 55 into a Model 60 resulted from an aerodynamics improvement program and a need to increase the capacity of the Learjet product line. Several of these modifications were a first for Learjet. They include an all new inboard wing cuff added to the inboard sections of the “Longhorn” wing and an all new wing-to-body fairing. By increasing the wing chord and the leading edge droop, the wing cuff improved handling during approach and landing while the wing-to-body fairing reduced the interference drag between the wing and the fuselage. Since the engines were new for this aircraft, a new engine pylon had to be designed.
The lines of the cockpit have not changed but the fuselage was lengthened. In addition, the blend between the fuselage and the empennage was all new. While it appears as if area ruling was the intension of the blending, the blend design was really driven by attaching the original Learjet Model 35 empennage onto the larger Learjet Model 60 fuselage. An all new E/B (Emergency/Baggage) door was added to the right-hand side of the fuselage just at the leading edge of the wing.
The final aerodynamic improvement to the Model 60 was the creation of the distinctive "Ogive" winglet trailing edge. This lengthening of the chord near the interface of the winglet and the wing improved the interaction of the wing’s pressure spike with the winglet’s pressure spike. The result was a significant lowering of the drag in this area and a significant improvement of the wing's efficiency. On the prior “Longhorn” wing the interference between the winglet and the wing nearly canceled the effects of the winglet.
The Learjet Model 45 winglet blend design took into account the lessons learned from the Model 60 and the ogive was not necessary.
The single ventral fin was replaced with two ventral fins that Learjet called "Delta Fins".
Production of the Learjet 60 ended in 2007 after 314 aircraft had been built.
Learjet 60 XR
The company launched a new variant in 2005 designated the Learjet 60 XR and following certification in 2005 deliveries started in 2007. The new 60 XR has an upgraded cabin, new avionics and other improvements.
One distinguishing characteristic of this aircraft is its time-to-climb. This aircraft can climb faster than most jets, making it very impressive to see.
The July 2008 issue of Flying magazine features the plane. |
