Rocket Engineering of Spokane, Wash., said it will soon have an STC to re-engine Beechcraft Duke BE60 twin pistons with two P&WC PT6A-35 or -21 turboprops. Preliminary performance of the “Royal Turbine” includes a 301-knot maximum cruise speed, 4,000-fpm climb rate, 7,000-pound mtow, 2,520-pound useful load and a 1,200-nm range. According to Rocket Engineering, the conversion will cost $887,000.