Spokane, Washington-based conversion specialist Rocket Engineering is developing a turboprop conversion for the Beechcraft Duke BE60 six-seat light piston twin, and hopes for certification within two months.
Dubbed the Royal Turbine, the re-engined Duke has been put through a series of flight tests since making its first sortie in September 2004. With Pratt & Whitney Canada PT6A-35 turboprops in place of its standard Lycoming TIO-541 pistons, the aircraft’s performance has improved dramatically, says Rocket, which has completed 60h of flight testing towards US Federal Aviation Administration supplemental type certification.
“Performance has been at or better than predicted, and service ceiling is better than we expected,” says Rocket sales and service consultant Doug Smith.
The aircraft has a 4,000ft/min (20.3m/s) rate of climb versus almost 1,600ft/min for the standard aircraft, and “at 18,000-19,000ft [5,500-5,800m] it has a single-engined rate of climb of around 1,500ft/s,” says Smith.
The Royal Turbine’s maximum cruise speed climbs to 300kt (555km/h) versus the standard aircraft’s 245kt, and maximum take-off weight increases from 3,080kg (6,780lb) to 3,180kg. The conversion costs $887,000.