McCook Field 1920's Prototype Wooden Airplane Propeller w/ Spinner

Rare McCook Field Prototype Wooden Propeller w/ Spinner – S.K. 5530 – 1920s U.S. Army Air Service Experimental Piece

This is a truly rare piece of early American aviation history. Stamped “McCook Field”, this 1920s prototype wooden propeller was part of the U.S. Army Air Service’s experimental development program at McCook Field in Dayton, Ohio — the nation's hub for cutting-edge aviation innovation after World War I.

Marked with MFG No. 03258 and S.K. 5530, this piece was likely used in wind tunnel testing or high-RPM structural experiments. The removable, hand-formed aluminum spinner cone exhibits wear consistent with heavy use, while the blades show signs of period repairs — all reinforcing its role in McCook’s hands-on R&D process.

McCook Field was the birthplace of modern military aircraft design. Between 1917 and 1927, its engineers and test pilots developed everything from variable-pitch propellers to altitude-capable engines and record-setting aircraft. Experimental items like this were often built in-house for engineering trials and performance validation — and each prototype was cataloged with a unique design number, such as “S.K. 5530”.

• Stamped on blades and hand-etched into hub: “McCook Field”, MFG No. 03258, S.K. 5530

• Dimensions: 31-1/2” long x 4-3/4” wide x 3” tall from bottom of hub to top of spinner

• Weight: Approx. 1 lb

• Condition: Excellent overall; blades show period-correct repairs, spinner is well-worn from testing — a testament to its use in experimental development

A phenomenal display piece for collectors, aviation museums, or anyone drawn to the pioneering days of flight testing and engineering.