Cessna AT-17 Bobcat


The Cessna AT-17 Bobcat is a twin-engined advanced trainer aircraft designed and made in the United States, and used during World War II to bridge the gap between single-engined trainers and twin-engined combat aircraft. The AT-17 was powered by two Jacobs R-755-9 radial engines. The commercial version was the Model T-50, from which the AT-17 was developed.

Design and development

The AT-17 was a military version of the commercial Cessna T-50 light transport. The Cessna Airplane Company first produced the wood and tubular steel, fabric-covered T-50 in 1939 for the civilian market, as a lightweight and low-cost twin for personal use where larger aircraft such as the Beech 18 would be too expensive. A low-wing cantilever monoplane, it featured retractable main landing gear and wing trailing edge flaps, both electrically actuated. The wing structure was built up of laminated spruce spar beams with spruce and plywood ribs. The fixed tailwheel is not steerable and full-swivelling. The prototype T-50 made its maiden flight on 26 March 1939.
In 1940, the United States Army Air Corps ordered them under the designation AT-8 as twin-engined advanced trainers.

Operational history

Thirty-three AT-8s were built for the U.S. Army Air Corps, and production continued under the designation AT-17 reflecting a change in equipment and engine types. In 1942, the U.S. Army Air Force adopted the Bobcat as a light personnel transport and those delivered after January 1, 1943 were designated UC-78s. By the end of World War II, Cessna had produced more than 4,600 Bobcats for the U.S. military, 67 of which were transferred to the United States Navy as JRC-1s. In addition, 822 Bobcats had been produced for the Royal Canadian Air Force as Crane Is, many of which were used in the British Commonwealth Air Training Plan. The aircraft did not last long in North American postwar military service. Few Bobcats were in service with the United States Air Force when it was formed in September, 1947. Surviving military aircraft were declared obsolete in 1949.
Dubbed the "Bamboo Bomber" by the pilots who flew them, it was one of the aircraft featured in the popular television series Sky King of the early-to-mid 1950s. The aircraft was replaced in later episodes by the T-50's successor, the all-metal Cessna 310.
After the war, surplus AT-17s and UC-78s could be converted by CAA-approved kits to civilian-standard aircraft allowing their certification under the T-50s original Type Certificate. They were used by small airlines, charter and "bush" operators and private pilots. Some were operated on floats. By the 1970s, the number of airworthy aircraft had dwindled as they were made obsolete by more modern types and by the maintenance required by their aging wood wing structures and fabric covering. Since then, several have been restored by antique airplane enthusiasts.
As of December 2017, FAA records show 52 T-50s, two AT-17s, and five UC-78s listed on its registration database.
In the postwar years, Bobcats continued in military service with Brazil and the Nationalist Chinese.

Variants

;T-50: Company design number. Five-seat twin-engined commercial transport aircraft, fitted with Jacobs L-4MB radial piston engines.
;AT-8: Military trainer version of the T-50 with two 295 hp Lycoming R-680-9 radial piston engines, 33 built.
;AT-17: As the AT-8 but powered by Jacobs R-755-9 engines, 450 built some later converted to AT-17E.
;AT-17A: As the AT-17 but with metal propellers and reduced weight, 223 built. 182 to Canada as Crane IAs and later conversion to AT-17Fs.
;AT-17B: As the AT-17A but with equipment changes, 466 built. Subsequent aircraft were built as UC-78Bs.
;AT-17C: As the AT-17A but different radio equipment, 60 built.
;AT-17D: As the AT-C with equipment changes, 131 built.
;AT-17E: AT-17 with gross weight limited to.
;AT-17F: AT-17A with gross weight limited to.
;AT-17G: AT-17B with gross weight limited to.
;C-78: Military transport version for the United States Army Air Forces, redesignated UC-78 in 1943, 1354 built.
;UC-78: C-78 redesignated in 1943; variable-pitch propellers.
;UC-78A: 17 impressed civilian T-50s
;UC-78B: Originally the AT-17B, wooden propellers and reduced weight, 1806 built.
;UC-78C: Originally the AT-17D, same as UC-78B with equipment changes, 196 built and 131 AT-17Ds redesignated.
;JRC-1: Navy light transport version of the UC-78 with two Jacobs -9 engines, 67 delivered.
;Crane I: Royal Canadian Air Force designation for T-50s with minor equipment changes, 640 delivered as light transports.
;Crane 1A: 182 AT-17As delivered to Canada under lend-lease.
;P-7: An experimental variant of the T-50 with more powerful Jacobs L-6MB engines, and plywood covered tailplane and wings, one aircraft only first flown June 2, 1941.
;P-10: 1941 advanced bomber trainer with modified fuselage, sliding canopy and Jacobs engines, 1 built.

Operators

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