This propeller was designed by the U.S. National Advisory Committee for Aeronautics (i.e. NASA’s predecessor) to reduce noise in light airplanes. The investigation was undertaken as an aid to the personal plane industry which had suffered from opposition to airports in built- up population areas. Research was conducted in 1946-47 utilizing noise studies dating back to 1935. The studies indicated that the noise level could be substantially reduced with a propeller having a large blade area and low tip speed. This propeller was one of two so designed. In tests on a Stinson L-5 airplane with a muffled 138 kw (185 hp) engine at 1000 rpm, flying 209 kph (130 mph) at 90 m (300 ft), this specially designed NACA propeller reduced the noise level of the airplane to the point where no distinct engine or propeller frequency could be heard from the ground.

 Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Date ca. 1946 Country of Origin United States of America Type PROPULSION-Propellers & Impellers Manufacturer National Advisory Committee for Aeronautics
 Physical Description Wood varnished with black leading edges, ground adjustable Type: Five-Blade, Fixed-Pitch, Various-Materials Diameter: 243.8 cm (96 in.) Chord: 35.6 cm (14 in.) Engine Application: Lycoming 0-435 Dimensions Rotor/Propeller: 243.8 x 35.6 x 106.7 x 30.5 x 27.9cm (96 x 14 x 42 x 12 x 11 in.)
 Materials Laminated wood, Plastic, Aluminum alloy, Steel, Paint, Museum Varnish
 Inventory Number A19500106000 Credit Line Transferred from the National Advisory Committee for Aeronautics Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
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