Boeing Stearman PT-17 Kaydet
Boeing · Primary Biplane Trainer · USA · WWII (1939–1945)
The Boeing Stearman PT-17 Kaydet (Stearman Model 75) was the U.S. Army Air Forces' primary biplane trainer during WWII — the aircraft on which over 60,000 American military pilots received their first training. Boeing-Stearman built 10,346 Kaydets between 1934 and 1945. The aircraft's open-cockpit two-seat biplane design was deliberately old-fashioned even for the late 1930s; the U.S. Army Air Corps wanted a forgiving primary trainer that would teach novice pilots basic stick-and-rudder skills before they transitioned to faster monoplane intermediate trainers (BT-9, BT-13) and eventually to combat aircraft. The Kaydet remains one of the most-iconic WWII-era trainers and is the subject of a thriving warbird community.
The PT-17 was a two-seat open-cockpit biplane with fixed tailwheel landing gear. Power: Continental R-670 Wright (later Lycoming R-680) 7-cylinder radial (220 hp). Maximum speed 124 mph; range 505 miles; service ceiling 11,200 ft. Empty weight only 1,936 lb; fully-loaded 2,717 lb. The aircraft was deliberately benign — slow stall, gentle handling, simple instrumentation, no complicated systems. Trainees could spin the Kaydet to its limits without risking the catastrophic loss-of-control accidents that more-later-stage trainers caused.
WWII initial training service was massive. About 60,000 U.S. military pilots learned to fly in Kaydets between 1939 and 1945. The U.S. Army Air Corps' main training plants (Gunter Field, Alabama; Randolph Field, Texas; Carlsbad Field, New Mexico; and dozens of contract civilian flying schools) all used the PT-17 as their primary trainer. U.S. Navy designations were N2S Kaydet (essentially identical airframe). Royal Canadian Air Force Kaydet 71 served the British Commonwealth Air Training Plan in Canada. Approximately 70% of U.S. WWII military pilots flew Kaydets at some point in their training pipeline.
Post-war the Kaydet was widely retired but found a marked second life in agricultural aerial-application service. About 4,000 surplus Kaydets were converted to crop-dusting in the late 1940s and 1950s; the aircraft's slow speed, large wing area, and rugged construction made it ideal for low-altitude pesticide application over fields. The Kaydet remained in active commercial agricultural service into the 1980s. About 1,500 Kaydet airframes survive in 2026, including a remarkable ~700 in airworthy condition — by far the most-numerous flying WWII-era warbird type.
For Kids — a shorter, friendlier version
The Boeing Stearman PT-17 Kaydet was a special airplane used during World War Two. It was a biplane, which means it had two sets of wings stacked on top of each other. The American military used it to teach brand-new pilots how to fly.
Over 60,000 American military pilots learned to fly in the Kaydet. That is a huge number of students! Boeing built 10,346 of these planes between 1934 and 1945. It was one of the busiest training planes ever made.
The Kaydet had two open cockpits, so both the student and the teacher could feel the wind on their faces. It flew at a top speed of 124 miles per hour. That is much slower than a fighter jet, but perfect for learning. The plane was easy to handle and hard to crash by mistake.
The Kaydet was heavier than a compact car when fully loaded, but it was still simple and safe to fly. Its gentle design let students practice tricky moves called spins without getting into real danger. Pilots called it forgiving, which means it was kind to beginners.
Today, about 700 Kaydets are still flying. That makes it the most common flying World War Two airplane in the world. People love to show them off at airshows and keep their history alive.
Fun Facts
- Over 60,000 pilots learned to fly in the Kaydet — that's like filling a big football stadium with student pilots!
- Boeing built 10,346 Kaydets, making it one of the most-produced trainer planes ever.
- The Kaydet had two open cockpits, so pilots felt the wind rushing past their faces while flying.
- Its top speed was 124 miles per hour, slower than many race cars but just right for beginners.
- The Kaydet is heavier than a compact car when fully loaded, yet still easy and gentle to fly.
- About 700 Kaydets are still flying today, making it the most-numerous flying World War Two airplane in the world.
- The plane had two sets of wings, which gave it extra lift and helped beginners feel stable in the air.
- Pilots loved the Kaydet because it was forgiving — even big mistakes in the air rarely caused serious trouble.
Kids’ Questions
Why did the military choose a biplane to train pilots?
The military wanted a plane that was easy and safe for beginners. The Kaydet's two wings and slow speed made it very stable and gentle to fly. Students could make mistakes and still land safely. It was the perfect first step before moving on to faster planes.
What does 'open cockpit' mean?
An open cockpit means there is no roof or windshield covering the pilot's seat. The pilot sits outside in the open air while flying. It can be cold and windy, but pilots could feel everything the plane was doing. Both the student and the teacher had their own open cockpit in the Kaydet.
Can I still see a Kaydet flying today?
Yes! About 700 Kaydets are still airworthy today. That means they can still fly safely. You can often spot them at airshows around the country. They are the most common flying World War Two airplane in the world.
Variants
- PT-13 / PT-17 / PT-18 / PT-27
- USAAC / USAAF designations. Different engines: PT-13 (Lycoming R-680), PT-17 (Continental R-670), PT-18 (Jacobs R-755), PT-27 (Continental R-670 winterised). PT-17 was the most-produced sub-variant at ~3,500 airframes.
- N2S Kaydet (US Navy)
- U.S. Navy designation for the same airframe. About 1,758 N2S-1 through N2S-5 built. Used by U.S. Navy and Marine Corps primary flight training.
- Kaydet 71 (RCAF / Commonwealth)
- Canadian and Commonwealth Air Training Plan trainer. About 350 delivered. Used in BCATP primary flight training in Canada.
- Crop-duster conversion
- Post-war agricultural conversion. About 4,000 surplus Kaydets converted to crop-dusters 1946-1955. Hopper installed in front cockpit, spray bars under wings. Continued commercial service into the 1980s.
Notable Operators
- U.S. Army Air Corps / U.S. Army Air Forces
- Largest user. Primary trainer for about 60,000 U.S. military pilots 1939-1945. Operated by every major U.S. flight-training base.
- U.S. Navy / U.S. Marine Corps (N2S Kaydet)
- About 1,758 N2S airframes. Used at Pensacola, Corpus Christi, and other Navy primary-training bases through 1948.
- Royal Canadian Air Force / RAF Empire Air Training Scheme
- About 350 Kaydet 71s for British Commonwealth Air Training Plan service in Canada.
- Civilian warbird operators (~700 airworthy)
- About 700 airworthy Kaydets operate worldwide in 2026 — by far the most-numerous flying WWII warbird type. Major events: National Stearman Fly-In (Galesburg, IL), Reading Aerodrome WWII Weekend, Oshkosh AirVenture.
Frequently Asked Questions
Why was the Kaydet a biplane?
The U.S. Army Air Corps deliberately specified an open-cockpit biplane for primary training, believing the slow, draggy biplane configuration would teach novice pilots fundamental aerodynamic skills (stalls, slips, slow flight) without the higher accident rate of fast monoplane primary trainers. The bet paid off; the Kaydet's training accident rate was markedly lower than the contemporary Vultee BT-13 Valiant intermediate trainer.
How many pilots did the Kaydet train?
About 60,000 U.S. military pilots between 1939 and 1945. Combined with U.S. Navy N2S users and Commonwealth Air Training Plan Kaydet 71 users, the total trained-pilot count exceeds 80,000. Approximately 70% of U.S. WWII military pilots flew Kaydets at some point in their training pipeline.
How many Kaydets were built?
10,346 airframes between 1934 and 1945. Production was at Boeing-Stearman's Wichita, Kansas plant. About 1,758 of those were U.S. Navy N2S variants. Production ended in 1945 with no post-war run.
Why are there so many Stearmans flying?
About 700 Kaydets are airworthy in 2026 — by far the most-numerous flying WWII-era warbird. The reason: about 4,000 surplus Kaydets entered civilian crop-dusting service after WWII and remained in-servicely active through the 1980s. When commercial agricultural use ended, large numbers of well-maintained airframes became available for warbird and personal use. The aircraft is also relatively cheap to operate (small radial engine, simple systems) compared with WWII fighters.
Did Kaydets see combat?
No — the PT-17 was strictly a primary trainer and never carried weapons. Some Kaydets were used as utility aircraft and forward air control aircraft in the early Pacific theatre, but no Kaydet engaged enemy forces in combat.
Sources
See Also
- North American T-6 Texan — Successor U.S. WWII later-stage trainer (next training stage)
- de Havilland Tiger Moth — British equivalent primary trainer biplane
- North American P-51 Mustang — Combat aircraft that Kaydet graduates eventually flew
- Supermarine Spitfire — Combat aircraft that Kaydet graduates eventually flew