In an announcement from company executives on August 30, 2016, Blackhawk Modifications, Inc. unveiled details about their newest XP Engine + Upgrade program, specifically for the King Air 350. Blackhawk is developing a Supplemental Type Certificate (STC) that will allow the installation and operation of the Pratt & Whitney Canada PT6A-67A engine, replacing the King Air 350’s existing PT6A-60A engines. The XP67A Engine+ Upgrade is currently installed on Blackhawk’s King Air 350 that will be used as the STC test aircraft during the experimental flight process. Blackhawk anticipates receiving the STC in May of 2017.
The PT6A-67A engine is a 1,200-SHP power plant that will replace the existing 1,050 SHP PT6A-60A engines currently certified on the King Air 350 model. Blackhawk’s STC will flat-rate the engine to 1,050 SHP, to take advantage of more than 400 thermodynamic shaft horsepower per engine in climb and cruise settings (1,825 ESHP). This higher thermodynamic rating will also improve takeoff and climb performance in high altitude and hot ambient temperature conditions.
The initial performance results have exceeded forecast projections. In hot climate conditions, the XP67A will climb from sea level to its service ceiling of FL350 in as little as 18 minutes – more than doubling the rate of climb. Stock engines take 45 minutes. Typical cruise speeds are increased by up to 37 KTAS and can settle in at up to 340 KTAS if an operator chooses to fly at maximum engine power limits. Operators looking for increased endurance and range can throttle back and extend capabilities due to better specific fuel consumption ratings. Blackhawk’s STC will include a new Flight Manual Supplement with full performance for flight planning purposes.
“We worked very closely with Pratt & Whitney to bring to market the best PT6 engine model that will boost the King Air 350 to the next level,” said Jim Allmon, President and CEO of Blackhawk. “The PT6A-67A pushes the King Air 350 above and beyond what can be achieved with many jets. The XP67A will attain jet-like speeds, can carry twice the payload much farther, and will burn a fraction of the fuel while lowering maintenance, operating and acquisition costs. It reintroduces the King Air 350 to a larger group of private, business and commercial operators as well as the special missions arena.”
The PT6A-67A engine will require a more robust propeller assembly. Blackhawk is now flying with the German-designed five-blade natural composite propellers from MT. Their diameter of 102 inches provides more ground clearance, and the MT propellers have unlimited blade life, are field reparable and employ large nickel alloy leading edges for superior erosion protection. The ground RPM restrictions are removed as well as the Ground Idle Solenoid to allow smooth taxi operations. The MT propellers also offer significant reductions in noise and vibration levels while demonstrating a positive contribution in overall performance. Hartzell 105-inch diameter five-blade composite propellers are also likely be included in the initial certification plan, as an option. Raisbeck Engineering is working on a migration path to upgrade its newly-certified Swept four-blade aluminum propeller assembly to be compatible with the PT6A-67A installation.
For more information, visit www.blackhawk.aero. •T&T