Public domain
Production. Airplane propellers. Finished propeller blades ready for assembly at a Hartford, Connecticut, plant. These blades will later be mounted in combinations of two, three and four in hydromatic mechanisms that permit adjustments of blade pitch while planes are in action
From the collection of Library of Congress. Free to download, adapt and use — no permission needed.
Credit lineProduction. Airplane propellers. Finished propeller blades ready for assembly at a Hartford, Connecticut, plant. These blades will later be mounted in combinations of two, three and four in hydromatic. 1942-01-01. United States. Office Of War Information, Feininger, Andreas. Farm Security Administration/Office of War Information Collection, Library of Congress. Public domain.