340+ knot Beechcraft King Air You thought your King Air was fast? Maybe it is to a certain point but with new improvements and a Supplemental Type Certificate (STC) from the FAA, Blackhawk is making sure King Air 300s are getting the most out of performance. It is really a combination of a number of elements to make this happen. Propeller manufacturer Hartzell is making a swept-tip 5-blade prop made from composite which makes the blades strong but also very light. The swept design also makes them more aerodynamically efficient as they operate, creating less drag which in turn positively affects the performance of the aircraft.