Hartzell and Marsh Aviation Introduce New Propeller System For Boeing North American
OV-10 Broncos.

Comprehensive Package of Upgrades
Modernizes the Entire Propulsion System.

The new Marsh OV-10 Bronco conversion is fitted with new Hartzell four-bladed propellers for increased performance, reliability and maintainability.
PIQUA, Ohio – April 2, 2004 – Hartzell Propeller Inc. announced today that it has made the first production delivery to Marsh Aviation of a new four-bladed propeller system designed to replace the aging original three-bladed propellers on Boeing North American OV-10 Bronco aircraft. The propellers are part of a conversion package developed by Marsh Aviation that includes modifications to the engine control system to accept the new Hartzell propellers. The conversion will provide operators with a modern, highly serviceable propeller that can take advantage of Hartzell’s extensive world wide support network. The system also features Hartzell’s latest airfoil technology with blades specifically designed for the broad speed, weight and maneuver spectrum of the OV-10 and OV-10D’s flight envelope.

Marsh has a foreign military contract to convert 10 OV-10s for the launch customer. The company also has contracts to upgrade an additional 18 OV-10A aircraft to the Hartzell Propeller system.

“While we wanted Hartzell propellers for our OV-10 conversion for their maintainability and reliability, their new design is also exceeding our expectations for its flight performance,” said Floyd Stilwell, CEO, Marsh Aviation.

The propeller features Hartzell’s proven steel hub turbine design with forged aluminum alloy blades. This combination has been utilized in thousands of utility aircraft applications with millions of flight hours in operation. The new OV-10 propellers measure 100 inches in diameter and are counter-rotating for use with the Marsh modified Honeywell (Garrett) T76 engines. The propellers have completed vibrational strain survey testing and are approved for use on all versions of the OV-10, including the higher-powered OV-10D model.

Marsh Aviation of Mesa, Arizona is one of the world’s leading modifiers of utility aircraft such as the OV-10. The company is also well-known for its work with Honeywell engine conversions and on military aircraft refurbishment. Prior to this most recent application, Marsh refurbished and converted 23 Grumman S-2 aircraft to 1200 gallon turbine powered tankers with Honeywell TPE331-14 engines and Hartzell five-bladed propellers for the California Department of Forestries. These aircraft replaced 25 radial engine powered 800 gallon S-2 air tankers. Dispatch rates for the new turbine powered aircraft configured with the Hartzell propellers increased by 35%. A similar Marsh S-2 conversion also set NAA records for altitude, speed and time-to-climb in its class.

For more information on the new OV-10 propeller conversion, contact Marsh Aviation at 480-832-3770. Fax 480-985-2840. Or email stilwell@marshaviation.com.

Hartzell Propeller Inc. is widely recognized as the leader in advanced propeller design and manufacturing technology. NASA has recognized Hartzell's advanced design capability by naming it the exclusive propeller partner for its General Aviation Propulsion (GAP) program. The company has recently developed the next generation of propeller designs based upon innovative “blended airfoil” technology and is manufacturing these blades on revolutionary machining centers to provide mission optimized performance for its customers. Hartzell traces its beginnings in 1917 to a relationship with Orville Wright and was founded on the principal of Built on Honor - a tradition that continues today. For more information visit the company on the Web at www.hartzellprop.com or fax your request to Hartzell at (937) 778-4321.