1936 Boeing Stearman PT -13
The Stearman (Boeing) Model 75 is an American biplane formerly used as a military trainer aircraft, of which at least 10,626 were built in the United States during the 1930s and 1940s. Stearman Aircraft became a subsidiary of Boeing in 1934. Widely known as the Stearman, Boeing Stearman, or Kaydet, it served as a primary trainer for the United States Army Air Forces, the United States Navy (as the NS and N2S), and with the Royal Canadian Air Force as the Kaydet throughout World War II. After the conflict was over, thousands of surplus aircraft were sold on the civilian market. In the immediate postwar years, they became popular as crop dusters and sports planes, and for aerobatic and wing walking use in air shows.
In late 1933, Stearman engineers Mac Short, Harold W. Zipp, and J. Jack Clark took a 1931 Lloyd Stearman design, and added cantilever landing gear and adjustable elevator trim tabs, to produce the Model 70. Able to withstand +12g and -9g, the aircraft was powered by a 210-hp Lycoming R-680, first flew on 1 January 1934, before flight tests were conducted at Wright Field, Naval Air Station Anacostia, and Pensacola. The Navy then requested a similar model built to Navy specifications, including a 200-hp Wright J-5 engine. The resultant Model 73, was designated NS-1 by the Navy, of which 41 were ordered, including enough spares to build another 20 aircraft.
In the summer of 1934, Stearman engineers refined the Model 73 into the Model X75. The Army Air Corps evaluated the plane that autumn, powered by a 225-hp Wright R-760 or a 225-hp Lycoming R-680. In July 1935, the Army Air Corps ordered 26 with the Lycoming engine, designated the PT-13A, while the navy ordered an additional 20. In August 1936, the Army ordered an additional 50 PT-13As, followed by another 30 in October, and another 28 in December. Simultaneously, the company received orders for its primary trainer from the Argentinian navy, the Philippine Army Air Corps, and the Brazilian Air Force. In January 1937, the army ordered another 26 PT-13As.
On 6 June 1941, the U.S. government issued Approved Type Certificate No. 743 for the civilian version of the Model 75. Designated the Model A75L3 (PT-13) and Model A75N1 (PT-17), about 60 were sold to civilian flights schools such as Parks College of Engineering, Aviation and Technology, and for export.
On 15 March 1941, the company delivered the 1000th trainer to the Army, and the 1001st trainer to the Navy. Then on 27 August 1941, the company delivered the 2000th trainer to the Army. On 27 July 1944, the company delivered its 10,000th primary trainer.
Tour the Cockpit!
Front Cockpit View
Rear Cockpit View
Post-war usage
After World War II, thousands of surplus PT-17s were auctioned off to civilians and former military pilots. Many were modified for crop-dusting use, with a hopper for pesticide or fertilizer fitted in place of the front cockpit. Additional equipment included pumps, spray bars, and nozzles mounted below the lower wings. A popular approved modification to increase the maximum takeoff weight and climb performance involved fitting a larger Pratt & Whitney R-985 Wasp Junior engine and a constant-speed propeller.
The Kaydet was a conventional biplane of rugged construction, with a large, fixed tailwheel undercarriage, and accommodation for the student and instructor in open cockpits in tandem. The radial engine was usually not cowled, although some Stearman operators choose to cowl the engine when using certain engine applications using increased horsepower, most notably the Red Baron Stearman Squadron.
Sources: Stearman Aircraft: A Detailed History – Phillip Edwards, United States Navy aircraft since 1911 – Peter Bowers, Stearman Guidebook, Wikipedia
This particular aircraft has been in the Ala Doble Flying Collection since its inception. Considered one of the collection cornerstones, it is serial number 1 of the PT-13s. Meaning it was the first Stearman trainer of its kind produced that was used in a long history of training WWII pilots that helped win us the war. It was acquired from the family of Bud Field who was a long -time friend and mentor of collection founder Walt Bowe. It currently resides at the Ala Doble Flying Ranch where it is maintained in flying condition.
1936 Boeing Stearman PT-13
- Crew: 2
- Registration: 75001
- Serial number: 75-001
- Fuel capacity: 46 US gallons
- Empty weight: 2,700 lb (1,225 kg)
- Gross weight: 4,230 lb (1,919 kg)
- Powerplant: Lycoming R-680 9-cylinder air-cooled radial piston engine, 220 hp
- Propellers: 2-bladed fixed-pitch propeller
- Performance:
- Maximum speed: 124 mph
- Cruise speed: 96 mph
- Dimensions:
- Length: 24 ft 9 in
- Wingspan: 32 ft 2 in
- Height: 9 ft 8 in
- Wing area: 298 sq ft
- Empty weight: 1,931 lb
- Max takeoff weight: 2,635 lb
