Cessna AT-17 Bobcat explained

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.

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,[1] and was issued Approved Type Certificate 722 on 24 March 1940.[2]

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 two Jacobs L-4MB radial engines rated at for takeoff. Production began in December 1939.[3]

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 US Army ordered an additional 450 AT-17s, based on the T-50. Modifications included additional cockpit windows and Jacobs R-755-9 engines.[3] Production for the U.S. Army Air Corps continued under the designation AT-17 reflecting a change in equipment and engine types. In 1942, the U.S. 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 as JRC-1s. The Navy 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.[4]

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).[5]

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.[2] 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.[6] [7] [8]

Notable appearances in media

It was featured in the popular television series Sky King of the early-to-mid 1950s.[3] 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 2 June 1941.
  • P-10: 1941 advanced bomber trainer with modified fuselage, sliding canopy and Jacobs engines, one built.[9]

    • 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, 1354 built.
  • UC-78: C-78 redesignated in 1943
  • UC-78A: 17 civilian T-50s 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

    Ethiopia

    Surviving aircraft

    References

    Bibliography

    Notes and References

    1. Wixley, 1984, p.13
    2. Juptner, 1994, pp.85-88
    3. Shiel, 1995, pp.15-16
    4. Swanborough, 1989, p.?
    5. Phillips, 1985, p.?
    6. Web site: FAA Registry - Aircraft - Make / Model Inquiry. faa.gov. 11 June 2016. 7 August 2016. https://web.archive.org/web/20160807033133/http://registry.faa.gov/aircraftinquiry/AcftRef_Results.aspx?Mfrtxt=CESSNA&Modeltxt=T-50&PageNo=1. dead.
    7. Web site: FAA Registry - Aircraft - Make / Model Inquiry. faa.gov. 11 June 2016. 7 August 2016. https://web.archive.org/web/20160807040957/http://registry.faa.gov/aircraftinquiry/AcftRef_Results.aspx?Mfrtxt=CESSNA&Modeltxt=AT-17&PageNo=1. dead.
    8. Web site: FAA Registry - Aircraft - Make / Model Inquiry. faa.gov. 11 June 2016. 7 August 2016. https://web.archive.org/web/20160807031439/http://registry.faa.gov/aircraftinquiry/AcftRef_Results.aspx?Mfrtxt=CESSNA&Modeltxt=UC-78&PageNo=1. dead.
    9. Web site: Cessna: P-10. aerofiles. 15 September 2018.
    10. Milberry, 1990, pp.456-459
    11. Jońca, 1985, p.12
    12. Bridgman, 1952, p.28
    13. Web site: Trinkle . Kevin . History of PSA . 2024-03-23 . www.psa-history.org . en-US.
    14. Skaarup, 2020
    15. Web site: Cessna Crane Mk. I . Canadian Warplane Heritage Museum . 21 December 2020.
    16. Web site: CESSNA CRANE. Canada Aviation and Space Museum. Canada Science and Technology Museums Corporation. 23 May 2017.
    17. Web site: Cessna UC-78B (JRC-1) Bobcat . 21 February 2022. Pima Air & Space Museum. Pima Air & Space Museum. pimaair.org. 2021. https://web.archive.org/web/20210302233147/https://pimaair.org/museum-aircraft/cessna-uc-78/. 2 March 2021. live.
    18. Web site: Cessna UC-78B Bobcat. 21 February 2022. National Museum of the United States Air Force. National Museum of the United States Air Force. nationalmuseum.af.mil. https://web.archive.org/web/20220202054227/https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/196259/cessna-uc-78b-bobcat/. 2 February 2022. live.

    This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Cessna AT-17 Bobcat".

    Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.