Press Releases

PIQUA, Ohio — April 28, 1994 — Hartzell announced today that AlliedSignal Engines is issuing a service bulletin which allows for reconfiguration of TPE331-8 and -10N engines required to accommodate Hartzell four-bladed propeller conversions on Cessna Conquest II aircraft.

The conversion, including modification of the engine, was approved by the FAA prior to the issuance of this bulletin, however, the installation now has AlliedSignal Engines’ recognition and acceptance. The bulletin is being issued in response to the large number of aircraft already converted and widespread acceptance of the new system. This AlliedSignal Engines Bulletin (TPE331-72-0904) enables operators to re-designate the model number of their engines to maintain proper configuration when undergoing maintenance and overhaul.

The bulletin provides procedures for properly converting the engine to accommodate the Hartzell props. This includes installation procedures for the 3103328-1 Plug and 897602-1 Cam included in the Hartzell propeller kit. Once this procedure is completed, the engine can be re-designated such that AlliedSignal Engines can recognize that these parts have been installed. For example, a TPE331-8-402S will become a TPE331-8-422S and a TPE331-10N-511S becomes a TPE331-10N-531S.

Hartzell engineers specifically designed the four-bladed system for the Conquest II application. As a result, the Hartzell four-blade system is the only conversion available that accommodates either of the two different beta tube systems installed on these aircraft without expensive additional parts. Beta tubes differ based upon the currently installed propellers — three-bladed Hartzell’s or three-bladed McCauley’s.

In the propeller conversion kit, Hartzell provides all the required AlliedSignal Engine hardware, including an 965664-5 Gasket (Propeller Pitch Control) which will allow compliance with Service Bulletin A72-0857 at the same time.

Hartzell Propeller Inc. is the world’s leading manufacturer of propeller systems enjoying 60 percent market share on turboprop airliners and 85 percent market share on corporate turboprops. The 76-year-old company is also well known for its design leadership having introduced the industry’s first full-feathering propeller for light twins, the first fully-reversing propellers for corporate turboprops and the industry’s first composite structure blades.