Cessna AT-17 Bobcat

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AT-17/UC-78 Bobcat
Crane
Model T-50
Role Trainer, five-seat light transport and utility aircraft
Manufacturer Cessna Aircraft Company
First flight 26 March 1939 (T-50)
Status retired
Primary users United States Army Air Forces
Royal Canadian Air Force
United States Navy
Produced 1939-1944
Number built 5,422

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[edit]

T-50 in flight

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 225 hp (168 kW) Jacobs L-4MB engines rated at 245 hp (183 kW) for takeoff. Production began in December 1939.[3]: 35–36, 45–46 

Operational history[edit]

UC-78 in flight

US Military[edit]

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 290 hp (220 kW) 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 245 hp (183 kW) Jacobs R-755-9 engines.[3]: 36–41  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. It was given the nickname the "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[edit]

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[edit]

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[edit]

It was featured in the popular television series Sky King of the early-to-mid 1950s.[3]: 44–45  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[edit]

Company designations[edit]

CAA (FAA precursor) Cessna T-50
T-50
fitted with Jacobs L-4MB radial piston engines.
P-7
experimental T-50 with more powerful 300 hp (220 kW) 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 330 hp (250 kW) Jacobs engines, one built.[9]

USAAC/USAAF designations[edit]

Cessna AT-17 trainer
Restored UC-78C
AT-8
Military advanced trainer with two 295 hp (220 kW) Lycoming R-680-9 radial piston engines, 33 built.
AT-17
As per AT-8 but powered by 245 hp (183 kW) 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 5,300 lb (2,400 kg).
AT-17F
AT-17A with gross weight limited to 5,300 lb (2,400 kg).
AT-17G
AT-17B with gross weight limited to 5,300 lb (2,400 kg).
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.
RCAF Cessna Crane as used in the BCATP at the Canadian Warplane Heritage Museum
UC-78C
AT-17D redesignated, 131 AT-17Ds redesignated and 196 built.

USN designation[edit]

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

RCAF designations[edit]

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

Operators[edit]

Cessna Crane mounted on floats for use as bushplane in Canada
 Brazil
 Canada
 Costa Rica
 Ethiopia
 France
 Guatemala
 Haiti
 Nicaragua
 North Yemen
 Republic of China
 Peru
 Poland
 United States

Surviving aircraft[edit]

UC-78 Bobcat of the National WASP Museum.

Specifications (AT-17)[edit]

3-view line drawing of the Cessna AT-17 Bobcat
3-view line drawing of the Cessna AT-17 Bobcat

General characteristics

  • Crew: pilot + four
  • Length: 32 ft 9 in (9.98 m)
  • Wingspan: 41 ft 11 in (12.78 m)
  • Height: 9 ft 11 in (3.02 m)
  • Wing area: 295 sq ft (27.4 m2)
  • Empty weight: 3,500 lb (1,588 kg)
  • Gross weight: 5,700 lb (2,585 kg)
  • Max takeoff weight: 6,062 lb (2,750 kg)
  • Powerplant: 2 × Jacobs R-755-9 seven-cylinder, air-cooled, radial piston engine, 245 hp (183 kW) each

Performance

  • Maximum speed: 195 mph (314 km/h, 169 kn)
  • Cruise speed: 175 mph (282 km/h, 152 kn)
  • Stall speed: 63–66 mph (101–106 km/h, 55–57 kn)
  • Range: 750 mi (1,210 km, 650 nmi)
  • Service ceiling: 22,000 ft (6,700 m)
  • Rate of climb: 1,150 ft/min (5.8 m/s)
  • Take-off run: 650 ft (200 m) to 50 ft (15 m)[note 1]
  • Landing run: 1,400 ft (430 m) from 50 ft (15 m) with a 90 mph (140 km/h) approach speed[note 1]

See also[edit]

Aircraft of comparable role, configuration, and era

Related lists

References[edit]

Notes[edit]

  1. ^ a b At a gross weight of 5,200 lb (2,400 kg)

Citations[edit]

  1. ^ Wixley, 1984, p.13
  2. ^ a b Juptner, 1994, pp.85-88
  3. ^ a b c Shiel, 1995, pp.15-16
  4. ^ Swanborough, 1989, p.?[page needed]
  5. ^ Phillips, 1985, p.?[page needed]
  6. ^ "FAA Registry - Aircraft - Make / Model Inquiry". faa.gov. Archived from the original on 7 August 2016. Retrieved 11 June 2016.
  7. ^ "FAA Registry - Aircraft - Make / Model Inquiry". faa.gov. Archived from the original on 7 August 2016. Retrieved 11 June 2016.
  8. ^ "FAA Registry - Aircraft - Make / Model Inquiry". faa.gov. Archived from the original on 7 August 2016. Retrieved 11 June 2016.
  9. ^ "Cessna: P-10". aerofiles. Retrieved 15 September 2018.
  10. ^ a b c d e f g h i j Milberry, 1990, pp.456-459
  11. ^ Jońca, 1985, p.12
  12. ^ Bridgman, 1952, p.28
  13. ^ Trinkle, Kevin. "History of PSA". www.psa-history.org. Retrieved 23 March 2024.
  14. ^ a b c d e f g h Skaarup, 2020
  15. ^ "Cessna Crane Mk. I". Canadian Warplane Heritage Museum. Retrieved 21 December 2020.
  16. ^ "CESSNA CRANE". Canada Aviation and Space Museum. Canada Science and Technology Museums Corporation. Retrieved 23 May 2017.
  17. ^ Pima Air & Space Museum (2021). "Cessna UC-78B (JRC-1) Bobcat". pimaair.org. Archived from the original on 2 March 2021. Retrieved 21 February 2022.
  18. ^ National Museum of the United States Air Force. "Cessna UC-78B Bobcat". nationalmuseum.af.mil. Archived from the original on 2 February 2022. Retrieved 21 February 2022.

Bibliography[edit]

  • Bridgman, Leonard (1952). Jane's All the World's Aircraft 1952–53. London, UK: Sampson Low, Marston & Co. ASIN B000S9SYD8.
  • "Cessna Model T-50". Aviation. Vol. 39, no. 1. January 1940. pp. 46–47.
  • Jońca, Adam (1985). Samoloty linii lotniczych 1945-1956 [Airplanes of the airlines 1945-1956]. Barwa w lotnictwie polskim no.4 (in Polish). Warsaw: Wydawnictwa Komunikacji i Łączności. p. 12. ISBN 8320605296.
  • Juptner, Joseph P (1994). U.S. Civil Aircraft Series, Vol.8. TAB Books. ISBN 0-816891788.
  • Milberry, Larry; Halliday, Hugh A. (1990). The Royal Canadian Air Force at War, 1939-1945. Toronto, ON: CANAV Books. ISBN 978-0921022046.
  • Mondey, David (2006). American Aircraft of World War II. Hamlyn Concise Guide. London, UK: Bounty Books. ISBN 978-0753714614.
  • Phillips, Edward H (1985). Cessna, A Master's Expression. Flying Books. ISBN 0911139044.
  • Shiel, Walt (1995). Cessna Warbirds, A Detailed & Personal History of Cessna's Involvement in the Armed Forces. Iola, WI: Jones Publishing. ISBN 978-1879825253.
  • Skaarup, Harold A. (6 February 2020). "Warplanes of the Second World War preserved in Canada". www.SilverHawkAuthor.com. Retrieved 16 October 2022.
  • Swanborough, Gordon; Bowers, Peter M. (1989). United States Military Aircraft Since 1909. Putnam. ISBN 085177816-X.
  • Wixley, Kenneth E. (January 1984). "Cessna Bobcat: A Production History". Aircraft Illustrated. Vol. 17, no. 1. pp. 13–16. ISSN 0002-2675.