The upgrade package on the King Air 350 promises more power and better perfomance. (07/22/2025)
Aircraft modification specialist Blackhawk Group has completed the application process for supplemental type certificate (STC) approval for its integration of the Hartzell advanced five-blade composite propeller with Blackhawk’s XP67A Engine+ upgrade on the Beechcraft King Air 350. The company said today at EAA Airventure that it has submitted all flight test data—derived through the installation of the package on its testbed King Air—to the FAA for validation.
According to Blackhawk, the upgrade provides a 24% increase in available horsepower (1,200 she), with improved performance including cruise speeds of more than 337 knots and climb to FL350 in less than 18 minutes.
Hartzell’s five-blade composite propellers offers a 10-pound weight reduction on each side of the aircraft versus standard four-blade aluminum propellers. Its reduced diameter also lowers cabin noise while enhancing occupant comfort and its blades offer unlimited service life.