Blackhawk Aerospace has received FAA supplemental type certificate (STC) approval for its XR Upgrade Kit for the King Air 350-series twin turboprop. The XR package increases cruise speed by 30 to 40 knots and maximum takeoff weight to 16,500 pounds, as well as cutting climb time to FL350 by 60 percent to 18 minutes. The modification reduces basic aircraft empty weight by 220 pounds and provides 25 percent more endurance and 24 percent more horsepower at typical loiter altitudes for the multi-role aircraft.
The XR kit replaces the original Pratt & Whitney PT6A-60A engines and four-bladed aluminum propellers with new 1,200-shp PT6A-67A engines and MT five-bladed composite propellers. It also includes new heavyweight landing gear, high floatation tires, Raisbeck fully enclosed high floatation gear doors, the True Blue Power TB44 lithium-ion battery, and conformal auxiliary CenTex Saddle tanks that are 172 pounds lighter than the OEM’s extra range fuel tanks.
The quieter propellers have higher ground clearance. The new lithium-ion battery yields a weight savings of 30 pounds and doubles cranking amps.