Cessna AT-17 Bobcat

The Cessna AT-17 Bobcat or Cessna Crane is a twin-engine advanced trainer aircraft designed and made in the United States, and used during World War II to bridge the gap between single-engine trainers and larger multi-engine combat aircraft. The commercial version was the Model T-50, from which the military versions were developed. Additional versions and names include the AT-8 trainer, UC-78 transport and bomber, and the Crane Mk.I in Canadian service.

Design and development

In 1939, three years after Clyde Cessna retired, the Cessna T-50 made its first flight, becoming the company's first twin-engine airplane, and its first retractable undercarriage airplane. The prototype T-50 first flew on 26 March 1939,Wixley 1984, p. 13. and was issued Approved Type Certificate 722 on 24 March 1940.Juptner 1994, pp. 85-88.

The AT-8, AT-17, C-78, UC-78, and Crane were military versions 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 lower cost twin for personal use where larger aircraft, such as the Beechcraft Model 18, would be too expensive. A low-wing cantilever monoplane, it featured retractable main landing gear and trailing edge wing flaps, both electrically actuated via chain-driven screws. The retracted main landing gear left some of the wheels extended below the engine nacelle for emergency wheel-up landings. The wing structure was built around laminated spruce spar beams, truss-style spruce and plywood ribs, and plywood wing leading edges and wing tips. The fixed tailwheel is not steerable, but can be locked straight. The Curtiss Reed metal fixed-pitch propellers were soon replaced with Hamilton Standard 2B-20-213 hydraulically-actuated, constant-speed, non-featherable propellers. Power was provided by a pair of Jacobs L-4MB radial engines rated at for takeoff. Production began in December 1939.Shiel 1995, pp. 15-16.

Operational history

US military On 19 July 1940, United States Assistant Secretary of War Louis A. Johnson ordered 33 AT-8 trainers, based on the T-50 for the United States Army Air Corps (USAAC). Modifications included cockpit roof windows, more powerful Lycoming R-680 engines and military radios. The first AT-8 was delivered to the USAAC in December 1940, and in late 1941, the United States Army ordered an additional 450 AT-17s, based on the T-50. Modifications included additional cockpit windows and Jacobs R-755-9 engines. Production for the USAAC continued under the designation AT-17 reflecting a change in equipment and engine types. In 1942, the United States Army Air Force (the successor to the Air Corps from June 1941) ordered the Bobcat as a light transport as C-78s, which were redesignated as UC-78s on 1 January 1943. By the end of World War II, Cessna had produced more than 4,600 Bobcats for the U.S. Army, 67 of which were transferred to the United States Navy (USN) as JRC-1s. The USN used the aircraft primarily for shuttling crews of ferry flights to and from their home bases. The Bobcat was given the nickname "Bamboo Bomber" in US service. Few Bobcats were still in service with the United States Air Force when it was formed in September 1947, and the type was declared obsolete in 1949.Swanborough 1989, p.?

Royal Canadian Air Force In September 1940, the Royal Canadian Air Force ordered 180 Crane Mk.I trainers, Cessna's largest order to date. Modifications for the RCAF included Hartzell fixed-pitch wooden propellers, removable cylinder head baffles, and oil heaters. The first Crane Mk.I was delivered to the RCAF in November 1940, and Cessna then received an additional order from the RCAF for 460 more Crane Mk.Is. An additional 182 AT-17A were received by the RCAF through lend-lease, operated under the designation Crane Mk.IA, bringing the total produced for the RCAF to 822, which were operated under the British Commonwealth Air Training Plan (BCATP).Phillips 1985, p.?

Other operators

In addition to military orders, the Civil Aeronautics Administration (CAA, precursor to the FAA) ordered 13 T-50s, and Pan American Airways ordered 14 T-50s. Aircraft operated by the US military and by the RCAF were retired shortly after the end of the war and many were exported worldwide including to Brazil and the Nationalist Chinese.

After the war, surplus AT-17s and UC-78s could be converted with CAA-approved kits to civilian-standard aircraft allowing their certification under the original T-50 approved 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.

By December 2017, 52 T-50s, two AT-17s, and five UC-78s were still listed on the Federal Aviation Administration's (FAA) registration database.

Notable appearances in media It was 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. One also stood in for Japanese twin engine bombers in the low level attack scene on the US PT boat base in the 1963 film, PT-109

Variants Company designations

T-50 Fitted with Jacobs L-4MB radial piston engines. P-7 Experimental T-50 with more powerful Jacobs L-6MB engines, and plywood covered tailplane and wings, one built, first flown on 2 June 1941. P-10 1941 advanced bomber trainer with modified fuselage, sliding canopy and Jacobs engines, one built.

USAAC/USAAF designations

AT-8 Military advanced trainer with two Lycoming R-680-9 radial piston engines, 33 built. AT-17 As per AT-8 but powered by Jacobs R-755-9 (L-4) engines, 450 built, some later converted to AT-17E. AT-17A As per AT-17 but with metal propellers and reduced weight, 223 built. 182 to Canada as Crane Mk.IAs and later conversions to AT-17Fs. AT-17B As per AT-17A but with equipment changes, wooden propellers and reduced weight, 466 built. Subsequent aircraft were built as UC-78Bs. AT-17C As per AT-17A but different radio equipment, 60 built. AT-17D As per AT-17C 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 Transport with variable-pitch propellers, became UC-78 in 1943, 1,354 aircraft built. UC-78 C-78 redesignated in 1943 UC-78A 17 civilian T-50s that were impressed. UC-78B AT-17B redesignated, 1806 built.

UC-78C AT-17D redesignated, 131 AT-17Ds redesignated and 196 built.

US Navy designation JRC-1 Navy light transport version of the UC-78 with two Jacobs -9 engines, 67 delivered.

RCAF designations Crane Mk.I 640 T-50s with minor equipment changes. Crane Mk.IA 182 AT-17As delivered to RCAF under lend-lease.

Operators

Brazilian Air Force (operated 39 from 1943 to 1956)

Royal Canadian Air Force (operated 822 from 1941 to 1949) No. 3 Service Flying Training School RCAF (SFTS) — Calgary, AlbertaMilberry 1990, pp. 456-459. No. 4 SFTS — RCAF Station Saskatoon No. 10 SFTS — RCAF Station Dauphin No. 11 SFTS — RCAF Station Yorkton No. 12 SFTS — RCAF Station Brandon No. 15 SFTS — RCAF Station Claresholm No. 1 Flying Instructor School — RCAF Station Trenton No. 2 Flying Instructor School — RCAF Station Vulcan/RCAF Station Pearce No. 3 Flying Instructor School — RCAF Station Arnprior Central Flying School — RCAF Station Trenton Queen Charlotte Airlines

Air Force of Costa Rica (operated one in 1948)

Ethiopian Air Force (operated two from 1946 to 1965)

French Air Force and French Navy (operated eight from 1943 to 1951)

Guatemalan Air Force (received one in 1949)

Haiti Air Corps (operated four from 1943 to 1995)

Nicaraguan Air Force (received two in 1947)

Yemeni Air Force (operated three from 1950 to 1958)

Republic of China Air Force (operated 15 from 1946 to 1950)

Peruvian Air Force (operated nine from 1945 to 1958)

LOT Polish Airlines (operated 14 in 1946-1950)Jońca 1985, p. 12.

Civil Aeronautics Authority United States Army Air Corps/United States Army Air Forces United States Navy Northern Consolidated Airlines Wiggins AirwaysBridgman 1952, p. 28. Wisconsin Central Airlines Friedkin Airlines

Surviving aircraft

Canada 7829 – Crane Mk.I at the Western Development Museum in Moose Jaw, Saskatchewan. 7862 – Crane Mk.I airworthy at the Canadian Warplane Heritage Museum in Hamilton, Ontario. 8676 – Crane Mk.I on static display at the Canada Aviation and Space Museum in Ottawa, Ontario. 8769 – Crane Mk.IA airworthy with Vintage Wings of Canada in Gatineau, Quebec. 8778 – Crane Mk.IA the Reynolds-Alberta Museum in Wetaskiwin, Alberta. 8841 – Crane in storage at the Memorial Military Museum in Campbellford, Ontario. c/n 3760 – UC-78B at the Bomber Command Museum of Canada in Nanton, Alberta. Crane on static display at the Commonwealth Air Training Plan Museum in Brandon, Manitoba. T-50 on static display at The Hangar Flight Museum in Calgary, Alberta.

United States 8139 – Crane Mk.I airworthy at the Wings of War Museum in Palmyra, Pennsylvania. 42-39162 – UC-78B on static display at the Pima Air & Space Museum in Tucson, Arizona. 42-71507 – UC-78 on display at the Western Antique Aeroplane & Automobile Museum in Hood River, Oregon. 42-71626 – UC-78B on static display at the National Museum of the United States Air Force in Dayton, Ohio. 42-71714 – UC-78B on static display at the Museum of Aviation in Warner Robins, Georgia. 43-1838 – UC-78 in storage at the Castle Air Museum in Atwater, California. 43-7995 – UC-78B on static display at the National Naval Aviation Museum in Pensacola, Florida. 43-31765 – UC-78 at the Military Aviation Museum in Virginia Beach, Virginia. 43-31917 – UC-78B under restoration at the Mid-Atlantic Air Museum in Reading, Pennsylvania. 43-32549 – UC-78A airworthy at the National WASP WWII Museum at Avenger Field in Sweetwater, Texas. 43-32578 – UC-78B airworthy with the Jayhawk Wing of the Commemorative Air Force in Wichita, Kansas. 43-81935 – UC-78B in storage at the Mid-Atlantic Air Museum in Reading, Pennsylvania. 3696 – JRC-1 airworthy at the American Heritage Museum in Stow, Massachusetts. 64469 – JRC-1 in storage at the Yanks Air Museum in Chino, California. c/n 4629 – T-50 in storage at the Alaska Aviation Museum in Anchorage, Alaska. c/n 6184 – T-50 at the Airpower Museum in Ottumwa, Iowa.

Specifications (AT-17)

See also

References

Notes

Citations

Bibliography