North America:1 (800) 942-7767 International:+1 (937) 778-4200

Hartzell Propeller Achieves Certification of Propellers for Walter M601 Turboprop Engines

Date: September 10, 2001 Category: Press Releases
Print Friendly, PDF & Email

Cascade Flying Service First to Certify New Hartzell / Walter Propulsion System

Hartzell Propeller Inc. has received certification from the Federal Aviation Administration (FAA) for a new propeller model designed specifically for installation on Walter M601 series turboprop engines.

PIQUA, Ohio – September 10, 2001 — Hartzell Propeller Inc. announced today that it has received type certification from the Federal Aviation Administration (FAA) for a new propeller model designed specifically for installation on Walter M601 series turboprop engines. Additionally, Cascade Flying Service of Garfield, Washington, has obtained a Supplemental Type Certificate (STC) for installation of this new Hartzell propeller and a Walter M601E-11 engine for Air Tractor AT-300 / 400 series aircraft.

Another installation of the Hartzell / Walter propulsion package is currently in development. Lancair of Redmond, Oregon, plans to offer this package as an option for its Lancair IVP kit.

Customer demand for improved performance propellers initiated Hartzell’s relationship with Walter a. s. of Prague, Czech Republic. In April 1999, the two companies embarked on a project to jointly develop and certify adaptations of Hartzell propellers and Walter turbine engines.

Previously, Walter’s engines utilized a propeller control system incompatible with Hartzell propellers. This system required a dual-acting propeller and relied upon a built-in mechanism within the prop for overspeed protection. Hartzell’s propellers in this power class utilize single-acting controls and an engine-driven overspeed governor. Walter and its control system supplier developed the appropriate modifications to accommodate the Hartzell propeller.

Extensive testing of this combination was conducted in Walter test cells throughout 2000. In addition to Walter’s certification testing, Hartzell was required to successfully complete endurance and functional pitch change cycle testing to achieve propeller certification of its new propeller model.

The new Steel Hub propellers, designated as HC-B3TW models, along with eligibility for use with the revised Walter control system, were added to Hartzell’s type certificate in February 2001. Hartzell plans to complete certification of the Lightweight Turbine Series for the Walter engines in late 2001.

Hartzell reached an important milestone in the project when it successfully completed a propeller vibration stress survey using a 106-inch diameter, three-blade Steel Hub Series propeller on a Walter M601 installed in an Air Tractor 401. The successful results of this test will allow this propeller to be certified on single-engine aircraft using the M601 and paved the way for Cascade Flying Service to complete its STC.

This 106-inch diameter feathering and reversing propeller is particularly well suited for agricultural and other utility aircraft applications where a high amount of thrust is required at low speeds. The 106-inch Hartzell provides 3100 pounds of static thrust when installed on the M601 E-11 engine. Flight tests by Cascade confirm that the propeller offers improved performance for Walter-equipped agricultural and utility type aircraft.

Cascade’s installation was first unveiled at the National Agricultural Aviation Association convention held last December in Reno and their STC was granted in January of this year.

“We’re extremely pleased with the performance of this engine and propeller combination on the Air Tractor aircraft we have converted,” said Doran Rogers, President and Owner of Cascade Flying Service. “Hartzell’s strong reputation in the agricultural aircraft market led us to select this high performance propeller.”

About Cascade Flying
Cascade Flying is a diverse multi-faceted aerial applicating company located in Eastern Washington and has been serving the farming communities of “The Palouse” for 30 years. Cascade Flying is an industry leader in the remanufacturing of wrecked Air Tractor aircraft. Believing in the Air Tractor plane for it’s quality and performance in 1992 Cascade Flying became an authorized Factory repair station for Air Tractor Inc.. For more information on Cascade’s Hartzell / Walter conversion of the Air Tractor AT-300 / 400 series aircraft contact them at (509) 635-1212, fax to (509) 635-1477, email to or visit the web at .

About Hartzell Propeller
Hartzell Propeller Inc. is the world’s leading manufacturer of propeller systems, well known for its advanced engineering and manufacturing capabilities. The company is rich in aviation heritage tracing its beginnings to relationships with Orville Wright and Glenn Curtiss. Significant technical innovations include 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. Hartzell was recently selected by NASA as the exclusive propeller partner for its General Aviation Propulsion (GAP) program – developing the next generation of general aviation propulsion systems.

For more information on Hartzell, fax your request to Hartzell at (937) 778-4321.

Hartzell Propeller