Maintenance and Modifications
Blackhawk STCs 5-blade Prop on XP67 Engine+ Upgrade
Composite propellers provide a quieter cabin and less exterior noise
Blackhawk XP67A Engine+ upgrade to the King Air 350
© Blackhawk Group

The FAA has approved a supplemental type certificate (STC) for Blackhawk Group’s integration of the Hartzell five-blade composite propeller on the King Air 350 XP67A Engine+ upgrade. That powerplant modification replaces the original Pratt & Whitney Canada PT6A-60A engines with 1,200-shp PT6A-67As.

Weighing about 10 pounds less than the four-blade aluminum propeller, the carbon-fiber five-blade propeller has a smaller diameter, reducing cabin and exterior noise. Development of the composite propeller included more than 50,000 flight-test hours, 20 lightning-strike simulations, and more than 200 bird-strike tests, according to Blackhawk.