PIQUA, Ohio — February 11, 1994 — Hartzell three-blade constant speed pusher propellers are significant aspects of the new Angel 44, an aircraft that was originally conceived for Christian missionary work. Hartzell’s long-term experience with pusher aircraft was one of the deciding factors. Hartzell props currently drive the vast majority of pusher configured aircraft including the Piaggio Avanti … the world’s fastest propeller driven business aircraft.
Those aircraft designed in a conventional tractor configuration create propeller air flow environments that are usually predictable from one aircraft to the next. Pusher configured aircraft, on the other hand, vary widely with different applications and it is typically difficult to predict the air flow environment and therefore more difficult to optimize the blade’s aerodynamic design. Piston powered pushers like the Angel 44 add one more interesting design element even compared to their turbine pusher brethren on account of more cumbersome piston engine nacelles which are difficult to fair aerodynamically.
Hartzell worked with the Angel 44 design team to build a propeller with a unique blade twist distribution. The inboard portion of the blade is a drastically reduced air flow area compared to the outboard area. As a result the transition area in the midsection of the blade features an unusually rapid rate of twist which observers of the aircraft will notice. Hartzell’s contributions to the aircraft include the aluminum blades with compact aluminum hubs as well as unusually long composite spinners that reduce drag and contribute to the aircraft’s impressive 13 hr. maximum endurance.
Along with missionary work, the Angel’s developers see potential uses for the aircraft in bush flying, surveillance, air ambulance, and fishery protection. For all of these applications, the pusher configuration contributes to the mission … superior visibility from aft movement of the engine nacelles, excellent low speed thrust and lift generation from undisturbed air flow over the wind, as well as ideal CG characteristics.
Hartzell Propeller Inc. is the world’s leading manufacturer of propeller systems, enjoying an 85 percent market share on corporate turboprops and a 60 percent share on turboprop airliners. The 76-year-old company is also well-known for its design leadership having introduced the industry’s first full-feathering propellers for light twins, the first fully-reversing propellers for corporate turboprops, and the industry’s first composite structure blades.
Pusher configured aircraft with Hartzell Propellers:
Embraer CBA 123 Vector
Piaggio Avanti P.180