1903 Wright Flyer Propeller
A propeller from the 1903 Wright Flyer. Wright propellers were large and rotated at a relatively slow speed. Those used on the first flight were 8-1/2 feet long and rotated at 350 rpm. In comparison, the single-engine Cessna 172, the most popular modern light aviation aircraft, typically has a propeller a little over 6 feet long that rotates up to 2,700 rpm. (U.S. Air Force photo)