The Nextant 400XT is a Beechjet 400A/Hawker 400XP with new Williams FJ44-3AP engines, a new Pro Line 21 avionics suite, a new cabin interior and an auxiliary power unit (APU). Williams implemented a low RPM Fadec control to the right-hand engine making it an APU.
The Raytheon Beechjet 400/400A evolved from the Mitsubishi Diamond 2 design that was bought by Beech in the mid-1980s.
The original Mitsubishi MU300 Diamond 1 flew for the first time in August 1978. In 1986, the Diamond 2 replaced the Diamond 1; however, only 11 Diamond 2s were built before Beech purchased the design and production rights. The Diamond 2 was renamed the Beechjet 400.
The Nextant 400XTi builds on the 400XT with the addition of raked winglets and auto-throttle, improving fuel economy and reducing the pilot workload. Inside the cabin, a new interior shell adds 3 inches of shoulder room and 2.5 inches of headroom, while the ambient noise is reduced with a new insulation package. Additionally, there are available cabin management and communications systems to match those found on a new jet in this class.
