Boeing Stearman Kaydet Primary TrainerJune 29, 2015
Posted on June 29, 2015
By Ray Panko | [email protected] | Pearl Harbor Aviation Museum
Why do we call it the Bush Stearman and why is it yellow?
“Boeing Stearman N67193” by Juergen Lehle — Own work (See also AlbSpotter Flugzeugbilder Aircraft Photos). Licensed under CC BY-SA 3.0 via Wikimedia Commons – https://commons.wikimedia.org/wiki/File:Boeing_Stearman_N67193.jpg#/media/File:Boeing_Stearman_N67193.jpg
- Key Points
- The Stearman “Kaydet”
- Flying the Stearman
- The George H.W. Bush Connection
- U.S. versus Japanese Flight Training
- Yellow Camouflage?
- Appendix; Additional Information
- Used in World War II Primary Training stage, in which pilot candidates first took to the air.
- Built by the Stearman Division of the Boeing Company.
- Usually called the Kaydet or simply “the Stearman,” it was the N2S to the Navy, the PT-13 or PT-17 to the Army, and the Kaydet to British Commonwealth forces. To Stearman, it was the Model 75.
- Simple (e.g., no flaps, etc.), to avoid overloading new pilot candidates.
- Rugged and docile, although its long nose made take-offs and landings difficult, and landing was a problem in crosswinds.
- The museum’s N2S-3 was flown by future president George H.W. Bush during his Primary Training.
- The yellow paint color was not camouflage. It was like a “new driver” sign in the back window of a car.
- Stages in training were Ground School, Primary Training, Basic Training, Advanced Training, and transitional training with a squadron. Note that Primary and Basic Training are different.
- The Army outsourced Primary Training to civilian flight schools, conserving its few combat pilots. The Navy did not.
The Stearman “Kaydet”
The bright yellow biplane in Hangar 37 is a Boeing Stearman Primary Trainer. Most World War II pilots remember it as the plane in which they first took to the air. Boeing’s Stearman Division called it the Model 75. To the U.S. Navy, it was the N2S. The U.S. Army called it the PT-13 or PT-17, depending on its engine. Canadians called their lend-lease version the Kaydet, and this name is widely used today for all Model 75s (Military Factory). For most instructors and students, it was simply “the Stearman.”
It took about a year to produce a combat-ready pilot. The first flying stage of pilot training was Primary Training. (This is why the Army designation began with PT.) Cadet pilots initially flew with an instructor pilot. Once they reached reasonable proficiency, they began to fly solo (without an instructor). The Stearman was balanced to fly solo from the rear seat (Wilson), which had better visibility to the sides than the front seat, but it could be flown solo from the front seat if weight was added to the back. Cadet pilots who passed Primary went through several more advanced stages of training.
Flying the Stearman
The simple Kaydet was a good airplane for first-time fliers. It had no flaps (Wilson), it lacked a radio and navigation instruments, its engine management was rudimentary, and there was no need to retract or extend the landing gear. Simplicity reduced mental workload. By the standards of other Primary Trainers and operational war aircraft, the cockpit was roomy (Davisson). It usually flew about 100 mph, and landing speed was a modest 60 mph. This further made it suitable for new pilots. It was also relatively docile. One pilot who flew in the Stearman (Wright) described the flying characteristics of the Stearman this way:
The stall is gentle, predictable, and recovery is straightforward. I doubt there is another airplane that stalls with such grace. It will spin when coaxed, but does so in such a docile and kind way that you may find yourself yawning while you recover.
The big Stearman was also easy to maintain (Davisson), and its rugged frame used tubes as thick as gas pipes, allowing it to survive student abuse (Davisson). Its price tag of $9,000 to $10,000 even made it a bargain (Davisson).
The Stearman was not entirely viceless, however. Its big nose made forward visibility nonexistent in take-offs and landings (Wilson). To taxi, the pilot had to make a series of S-turns to see ahead. The actual take-off and landing were done primarily by looking off to the sides (Wilson).
Its biggest problem was that the Kaydet was treacherous to land in a crosswind (Davisson). In fact, the original flight manual said to avoid crosswind landings (Wright). Fortunately, crosswinds were less of a problem in World War II than they are today. Training fields were generally large rectangles without runways, so the pilot could usually land into the wind by keeping an eye on the field’s windsock. When this was not possible, however, problems abounded.
By the end of Primary, however, successful candidates were reasonably good at unpowered landings, stall recoveries, and mild aerobatics. In subsequent flight training stages, the candidates flew progressively more powerful and complex aircraft on more complicated missions. They built and honed their skills in long-distance navigation, radio use, night flying, instrument flying, formation flying, and, of course, gunnery and air-combat maneuvering.
Boeing Stearman Doing Acrobatics
Air Force Historical Research Agency, Photo 080129-f-3927s-253.
The George H.W. Bush Connection
The museum’s Stearman is a Navy N2S-3 (BuNo 92468, C/N 75-6707). The museum calls it the “Bush Stearman” because the future president made several solo flights in this particular airplane (although not his first solo) during Primary Training. At 18, George H.W. Bush became the youngest Navy pilot to earn his wings. Aboard the aircraft carrier USS San Jacinto (CVL-30), he flew a Grumman TBM Avenger. In 1943, Bush was flying a mission over Chichijima island. During his bombing run, ground fire crippled his aircraft. Bush was able to bail out over the ocean, but his two crewmen were not. Fortunately, the submarine USS Finback was waiting to pull him out of the water. Bush ultimately flew 58 combat missions. He received the Distinguished Flying Cross and three Air Medals.
George Bush and an Avenger
“TBF GeorgeBush.” Licensed under Public Domain via Wikimedia Commons — https://commons.wikimedia.org/wiki/File:TBF_GeorgeBush.jpg#/media/File:TBF_GeorgeBush.jpg
“TBF early1942” by US Government — Originally uploaded to en.wikipedia by Felix c www.daveswarbirds.com. Licensed under Public Domain via Wikimedia Commons — https://commons.wikimedia.org/wiki/File:TBF_early1942.jpg#/media/File:TBF_early1942.jpg
A good question for young visitors is, “Why is this airplane yellow?” They probably know that aircraft in World War II were camouflaged in dull colors to make them less visible. Beginning in the 1920s, however, both the Navy and the Army Air Corps painted the wings and tail surface of their airplanes bright yellow. (Navy fuselages were gray; Air Corps fuselages were olive drab or blue.) The idea was to make the aircraft highly visible in the sky and on the ground to reduce accidents. When the Navy and Air Corps began camouflaging their combat aircraft in 1940, trainers remained brightly colored. The Navy painted the Stearman’s fuselage and wings bright yellow, while the Army retained the prewar yellow and blue colors. By 1943, however, newly built Stearmans for both services were finished in overall silver.
The yellow was the equivalent of a “student driver” sign in the back window of a car. It warned other aircraft to give the cadet pilot a little more room. Pilot candidates also joked that yellow made it easier to find the wreckage. Pilots often called the plane the “yellow peril.” However, “yellow peril” was also a racist slur against the Japanese.
A red stripe around the fuselage and wings signified that the aircraft was additionally outfitted as an instrument trainer. When the red dot was dropped from the national insignia in 1942 (to make it seem less Japanese), the red stripes were gradually changed to a medium green color (Dana Bell).
“Stearman.e75.g-bswc.longshot.arp.” Licensed under Public Domain via Wikimedia Commons — https://commons.wikimedia.org/wiki/File:Stearman.e75.g-bswc.longshot.arp.jpg#/media/File:Stearman.e75.g-bswc.longshot.arp.jpg
Characteristics (All Models; Ours is an N2S-3)
|Boeing Stearman Model Number||Wichita 75|
|Our Aircraft Model Number||N2S-3|
|Number Built, All Models||8,585 assembled, plus 1,785 aircraft worth of parts. (Davidson)
N2S-3: 1,875 (Wikipedia)
|Crew||2 (student pilot in back, instructor in front)|
|Length||24 feet, 3 inches|
|Wingspan||32 feet, 2 inches|
|Empty Weight (Davisson)||1,935 lbs|
|Maximum Weight||2,717 lbs|
|Top Speed||124 mph|
|Cruising Speed||106 mph|
|Engine||PT-13 or N2S: 9-cylinder 225 hp Lycoming R-680 (Davisson)
N2S-3: R-670-4 (Wikipedia)
PT-17: 7-cylinder 220 hp Continental R-670 (Davisson)
Source: Unless otherwise noted, the Boeing Company.
Note: Performance was nearly identical for all models.
Appendix: Additional Notes
Primary Training: Army Vs. Navy
There was an interesting difference in how the Navy and Army conducted Primary Training. The Navy taught all phases of training itself, including Primary. The Army outsourced Primary Training to civilian flight schools. The military gave them both the trainers they needed to teach their military student. PT was essentially the same training that civilian private pilots received to pass their license exams, so there were no problems in outsourcing. For quality control, however, each student had to pass a final check ride with a military pilot.
Outsourcing Primary allowed the Army to conserve its pilot corps. Fewer had to be taken out of operational squadrons to train pilots in Primary. Primary Training was a particularly good phase to outsource because it was the phase in which most candidates washed out.
Later Stages of Training
Training was a massive undertaking during World War II. The Army alone trained more than 324,000 pilots during the war.
- Ground School. Even before Primary, there was a Ground School phase. Here, the pilot candidates learned core flight concepts. Many failed this phase of training, but those who graduated had a solid understanding of core aeronautics concepts and principles.
- Primary Training. As noted earlier, PT taught pilots civilian private flying skills.
- Basic Training. After Primary, the students began Basic Training. Students flew a two-seater that was more complex than the Stearman. In Basic, students began to learn military flying. They learned to fly longer distances and flew more complex missions.
- Advanced Training. In Advanced Training, the pilot candidate flew an airplane with roughly the performance and complexity of a fighter. Higher performance required a more complex aircraft that took far more management than Primary and Basic trainers. Pilots learned close formation flying, long-distance flying under difficult conditions, gunnery, and air combat maneuvering.
- Transitional Training. After Advanced Training, the pilot candidate earned his wings. However, training did not end. He moved into a squadron with the fighter he would be using in combat. There was a lot to learn about this particular aircraft and real-world combat flying in general. Before the war, new pilots went to operational squadrons for this final training. Once the war started, however, the services created dedicated transitional squadrons to teach the pilot combat skills before going into actual combat.
Multiengine pilots, navigators, and bombardiers diverged from the fighter pilot sequence at some point. Multi-engine cadet pilots flew in small two-engine aircraft to learn the intricacies of managing multiple engines and coping with skewed thrust if the aircraft lost an engine. Bombardiers flew small bombers that dropped practice bombs. Navigators had flying classrooms in which a group of candidates did real navigation exercises for their aircraft. Gunners and mechanics had their own training sequences.
Crosswind Landings in a Stearman
Crosswinds were problematic because the airplane’s high center of gravity and the narrow landing gear were a perfect recipe for a ground loop (Wright), in which the airplane touched the ground and then pivoted around one wheel. This usually did substantial damage and could even prove fatal. Crosswinds often produced ground loops in a Stearman. Even before touchdown, a crosswind made the airplane difficult to keep level (Wright). During the actual touch down, the pilot had to place the windward side of the landing gear down first, so that the crosswind planted the second wheel off the ground instead of lifting the windward wheel. All of this is daunting for even an experienced pilot.
We have used the term Army rather than U.S. Army Air Corps or U.S. Army Air Forces. The Air Corps became the Air Forces on June 20, 1941. The training saga spans the two naming periods, and this can be confusing. The separate United States Air Force was not established until Sept. 17, 1947.
For brevity, the preceding text only mentioned the PT-13, PT-17, and N2S versions of the Model 75. There were a few others, but their numbers were insignificant. The PT-18 was a PT-13 with a 245-horsepower Jacobs R-755 radial; 150 were built. Three hundred PT-17s were supplied to Canada as lend-lease aircraft; they were designated PT-27s. The NS was the precursor to the N2S. It used a surplus Wright J-5 Whirlwind with 220 hp. About 60 were built. All Model 75s had nearly the same power, so performance differences were small.
The Stearman was not the only Primary Trainer. The next most common was the Ryan PT-22 Recruit. This was a monoplane used by the Army. It only had 160 hp but was lighter than the Stearman, with an empty weight of 1,308 lbs (593 kg). This gave the Recruit and the Stearman nearly identical performance. Harrison Ford was flying one of these aircraft when he crashed on a golf course in March 2015. The Navy version was the NR-1: many of these had their wings clipped and could only taxi while they taught crosswind landings. The services used other primary trainers in small numbers.
The blue SNJ in Hangar 79 was the most common advanced trainer for the Navy in World War II. The Army called it the AT-6 Texan, while Commonwealth countries dubbed it the “Harvard.” Docents at the museum who flew it said that it handled very much like an SBD Dauntless scout/dive-bomber.
Ryan PT-22 Primary Trainer
“Ryanpt22” by Tram2 at English Wikipedia. Licensed under CC BY-SA 3.0 via Wikimedia Commons – https://commons.wikimedia.org/wiki/File:Ryanpt22.jpg#/media/File:Ryanpt22.jpg
Boeing Company, Stearman Kaydet Trainer. http://www.boeing.com/history/products/stearman-kaydet-trainer.page
Davisson, Bud, Air Progress Vintage Guide, 1989. http://www.airbum.com/PriepStearmanPT17.html.
Military Factory, Boeing-Stearman Kaydet Trainer Aircraft (1941), version of June 20, 2013. http://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=334.
Wilson, Randy, “Flying the Army Primary Trainers: A Comparison of the Stearman, Fairchild, and Ryan PTs, The Dispatch, 24(2) (Summer 1999). Commemorative Air Force.
Wikipedia, Boeing-Stearman Model 75, https://en.wikipedia.org/wiki/Boeing-Stearman_Model_75. Last accessed June 14, 2015.
Wright, Theodore, Love Affair with a Stearman. http://flightaware.com/squawks/view/1/unset/user/36390/Love_Affair_with_a_Stearman.