The Bell 400 TwinRanger was a prototype four-bladed, twin-engine civil helicopter developed by Bell Helicopter in the 1980s. Both the TwinRanger and another planned version, the Bell 440, were attempts to market a twin-engine development of the Model 206L LongRanger. The Bell 400A was a planned single-engine version of the 400. TwinRanger, however development was canceled when Bell could not acquire enough orders for production. The TwinRanger name was later used for a twin-engine version of the LongRanger produced from 1994 to 1997.
Bell has tried several incarnations of a twin-engine version of its successful Bell 206 series. The TwinRanger name dates back to the mid-1980s when Bell first considered developing a twin-engine version of the LongRanger.
The Bell 400 TwinRanger featured a reprofiled fuselage, two Allison 250 turboshafts, the OH-58D Kiowa's four-bladed main rotor, and a new shrouded tail rotor.[1] Bell also planned the single-engine 400A, and the 440 twin with a larger fuselage made possible by a high degree of composites.[2] The Bell 400 first flew on April 4, 1984. Bell suspended development of the 400/440 family in the late 1980s as it felt unable to achieve a profitable production rate of 120 units a year.[1]
After the success of Tridair's Gemini ST twin-engine conversions of the 206L in the early 1990s, Bell produced the equivalent Bell 206LT TwinRanger based on the 206L-4. Only 13 206LTs were built between 1994 and 1997. The 206LT was replaced in Bell's lineup by the Bell 427, a mostly-new development of the Bell 407, itself a four-bladed single-engine derivative of the 206L.[1]