The Cessna AT-17 Bobcat or Cessna Crane 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 larger multi-engined combat aircraft. The commercial version was the Model T-50, from which the military versions were developed.
|Role||Trainer, five-seat light transport and utility aircraft|
|Manufacturer||Cessna Aircraft Company|
|First flight||26 March 1939 (T-50)|
|Primary users||United States Army Air Forces|
Royal Canadian Air Force
United States Navy
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, and was issued Approved Type Certificate 722 on 24 March 1940.
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.: 35–36, 45–46
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.: 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.
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).
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.
Aircraft of comparable role, configuration, and era