Several former engineers of the failed Franklin Automobile Company formed Air Cooled Motors in 1935. By 1938 a range of flat-4 and 6 aircraft engines was being produced, retaining the Franklin name. This post-war product was the largest model. In 1975, the company disbanded and sold all rights to the Polish government, becoming part of PZL, an association of Polish aero and engine manufacturers. Following the 1989 fall of Communism, the firm became WSK PZL – Rzeszów.

This is an early vertically-mounted, fan-cooled helicopter engine. The Aircooled Motors (Franklin) O-405-9 was installed in the Sikorsky XH-6A, YH-6A, H-6A, YH-6, Sikorsky XH-7, Kellett XH-8, and XH-8A helicopters. The Franklin designation for this engine was 6ACV-403.

 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 Circa1943 Country of Origin United States of America Type PROPULSION-Reciprocating & Rotary Manufacturer Aircooled Motors Corporation (Franklin)
 Physical Description Type: Reciprocating, opposed-type, 6 cylinders, air-cooled Power rating: 183 kW (245 hp) at 3,275 rpm Displacement: 6.97 L (425 cu in.) Bore and Stroke: 121 mm (4.75 in.) x 102 mm (4 in.) Weight: 207.7 kg (458 lb) Dimensions Length 108.3 cm (42.6 in.), Width 112.4 cm 44.25 in.), Height 131.4 cm (51.75 in.)
 Materials HAZMAT: Cadmium Plating
Aluminum
Paint
Steel
Paper
Ink
Adhesive
Synthetic Rubber
 Inventory Number A19600105000 Credit Line Transferred from the U.S. Air Force Central Museum Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
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