The PT-13 Kaydet was one of several different trainers that were introduced by the Stearman Company. Nearly every American pilot who flew fighters, bombers, or cargo planes during World War II got their first flying lessons in a Kaydet.
“Icons of Aviation History” is a diary series that explores significant and historic aircraft.
By the mid-1930s, the US needed a new airplane for basic flight training. Warplane design had advanced rapidly, from cloth-covered biplanes to all-metal mono-wings, but the United States had not kept up—the US Army Air Force and Navy were still using the PT-3 Trusty, introduced back in 1927, as their primary trainer for new pilots. (At this time, the training for American military pilots happened in three stages with three different airplanes: the “primary trainer” was used for teaching new students how to fly, the “basic trainer” was used for instruction in subjects such as formation flying and aerial gunnery, and an “advanced trainer” was a more powerful aircraft intended to prepare students in air tactics before they began specific training in the type of airplane they would be using in their combat assignment. The rate of student failure, known as “washing out”, usually got higher with each step.)
In the inter-war years, though, America was stuck in a wave of isolationism, and nobody in Congress wanted to spend money to modernize the military. It wasn’t until 1935, with war clouds looming in both Europe and the Pacific, that enough funding was finally provided for a new training aircraft.
The Stearman Company, however, anticipating that the military would be looking for a new trainer soon, had already began design work on its Model 75 airplane in 1934. It was, at the time it was introduced, already an obsolete design: a fabric-covered biplane in an era when all-metal mono-wings were supreme. But the Stearman was very stable at low speeds and was easy to control, making it very good for training rookie pilots. It also used a radial engine, which was reliable, durable, and easy to repair. Both the Army Air Corps and the Navy began ordering two-seat versions of the biplane for use as basic trainers.
There were a bewildering variety of Stearman trainers, differing mostly in which engine had been fitted to them. The first production models obtained in 1935 used a Lycoming R-680 engine, and they received the Army designation PT-13. After the Boeing Company purchased Stearman in 1936, they continued to produce PT-13s. But as war came closer, the military began ordering them in increasing numbers—3500 in 1940 alone—and the manufacturers were unable to keep up. When bottlenecks began to appear in the fabrication of Lycoming engines, the Army Air Corps, anxious to maintain production, ordered that the more readily-available Continental R-670 engine be fitted to the same airframe, designating the resulting plane as the PT-17. With a 220-horsepower radial engine and a top speed of around 125mph, this would be the most widely-produced variant, but others followed. In 1942, in turn, now faced with a shortage of Continental engines, Stearman began using the Jacobs R-755-7 instead, and this variant was listed as the PT-18.
The Navy, meanwhile, was using the same airframe for its own primary trainer, but with a different variety of radial engines, and they used the designation N2S instead of PT. At one point in 1942, both the Army and Navy found themselves using the same Lycoming R-680-17 engine, and the Army PT-13D and Navy N2S-5 were identical—the only time this ever happened. A number of the Army versions were also sent to Canada under Lend-Lease. At first these were equipped with the standard open cockpits, but during winter training the Canadians decided that they didn’t like this very much and installed enclosed cockpits.
The Stearman was a superb training platform. As with all trainers, the plane had dual cockpits, with the student sitting in front and the instructor in back. The instructor had a duplicate set of flight controls and could take over immediately if the student got himself into trouble. The big engine was powerful but the airframe had handling characteristics that were forgiving, especially for takeoffs and landings, making it easier for student pilots to learn the basics. Somewhat inconsistently, it soon earned the nickname “The Yellow Peril”; this was perhaps because of its bright yellow and blue paint scheme, perhaps because the high washout rate was hazardous to a young pilot’s career, or perhaps because whenever a student pilot was flying it near you never knew what he was going to do next. But it was the Canadians who gave the plane the nickname by which it is still most widely known: the Kaydet.
In all, over 10,000 Kaydets of various models (mostly PT-17s) were produced during the war, with the last one rolling off the Boeing assembly line in Wichita KS in February 1945. Although the Air Force continued to use the Stearman as a basic trainer well into the jet age, after the war several thousand of the planes were declared surplus and sold. Through the 1950’s, many found use as agricultural crop dusters; large numbers of these were fitted with newer Pratt and Whitney R-985 engines with 450 horsepower. By the 1960s, restored to their original military specs, they were appearing at air shows. Today, 75 years after production stopped, there are at least 1,000 Kaydets still flying.
The PT-13D obtained by the Smithsonian Air and Space Museum was manufactured in 1944 and used at the Moton Field training base in Tuskagee, Alabama, to train members of the famous “Tuskagee Airmen”, the first African-American fighter squadron. Originally exhibited at the Museum’s Udvar-Hazy Center, it is now housed in the National Museum of African American History and Culture.
NOTE: As some of you already know, all of my diaries here are draft chapters for a number of books I am working on. So I welcome any corrections you may have, whether it's typos or places that are unclear or factual errors. I think of y'all as my pre-publication editors and proofreaders. ;)
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