Origins The T-37 can be traced back to the spring of 1952 and the issuing of a request for proposals by the
United States Air Force (USAF) for what would become the "Trainer Experimental (TX)" program. The request called for a lightweight twin-seat basic trainer that would be suitable for introducing USAF cadets to jet aircraft. More specifically, the aircraft had to be simple to operate, easy to maintain, structurally strong, possess favourable low-speed handling qualities, be relatively safe while performing high altitude maneuvers, adequate fuel capacity for at least two flight hours, a service ceiling of 30,000 feet, a maximum approach speed of 113 knots, a maximum all-up weight of 4,000 lbs, and the ability to land and take off in less than 4,000 feet. Cessna was one of eight aircraft manufacturers to respond to the TX request, the company designed a twin-jet aircraft with
side-by-side seating that it internally designated as the
Model 318. The XT-37 was fitted with a pair of
Continental-Teledyne J69-T-9
turbojet engines, which were
French Turbomeca Marboré engines produced under
license, each being capable of generating up to 920
lbf (4.1 k
N) of
thrust. Many of the aircraft's components were designed and built internally by Cessna; relatively few external
contractors were involved in the production. however, due to the cockpit being
unpressurized, it was limited to an operational ceiling of by USAF regulations. The initial prototype crashed during
spin tests. To improve handling, subsequent prototypes were equipped with new aerodynamic features, such as lengthy
strakes along the nose and an extensively redesigned and enlarged
tail. On 3 May 1955, the third and final prototype took flight for the first time. in 2007 operated as part of the Euro-NATO Joint Jet Pilot Training Program.
Production The production T-37A was similar to the XT-37 prototypes, differing only in only minor ways as to address problems revealed by flight testing. During September 1955, the first T-37A was completed, it made its first flight later that year. The USAF ultimately ordered 444 T-37As, the last of which was produced in 1959. During 1957, the US Army evaluated three T-37As for battlefield observation and other combat support roles, but eventually procured the
Grumman OV-1 Mohawk for this purpose instead. Darling alleges that this outcome had been largely due to political factors, including the opposition of the USAF. USAF officials reportedly liked the T-37A but often considered it to be underpowered; consequently, the service ordered an improved version, the
T-37B. It was outfitted with uprated J-69-T-25 engines that provided roughly 10 percent more thrust as well as being more reliable. The new variant also featured improved
avionics, fuel flow improvements, as well as various changes to reduce maintenance requirements. Following a series of accidents caused by
bird strikes between 1965 and 1970, all T-37s were later retrofitted with a new windshield made of
Lexan polycarbonate plastic 0.5 in (12.7 mm) thick; this had sufficient strength to reliably withstand the impact of a bird at a relative speed of . While early examples of this new windshield suffered from distortion, this was rectified via production changes. In 1962, Cessna suggested the T-37B as a replacement for the
North American F-100 Super Sabre as the primary aircraft for the USAF aerobatic demonstration team, the
Thunderbirds, but the USAF was satisfied with the F-100. The T-37A and T-37B had no built-in armament and lacked any
stores pylons for external armament. During 1961, Cessna began developing a modest enhancement of the T-37 for use as a weapons trainer. The new variant, the designated
T-37C, was intended for
export and could be used for light attack duties if required. The prototype T-37C was a modified T-37B; the principal changes made included strengthened wings and the addition of a stores pylon under each wing outboard of the main landing gear well. The T-37C could also be fitted with a
reconnaissance camera mounted inside the
fuselage. It could also be fitted with wingtip fuel tanks, each with a capacity of 65 US gal (245 L), that could be dropped in an emergency. The primary armament of the T-37C was the
General Electric "multipurpose pod" with a .50 caliber (12.7 mm)
machine gun with 200 rounds, two 70 mm (2.75 in) folding-fin
rocket pods, and four practice
bombs. Other stores, such as folding-fin rocket pods or
Sidewinder air-to-air missiles, could be carried. A computing
gunsight and
gun camera were also added. The changes increased the weight of the T-37C by . As the engines were not upgraded, the changes caused a reduction in the aircraft's top speed to 595 km/h (370 mph), though the wingtip tanks increased its maximum range to 1,770 km (1,100 mi). Production of the T-37 slowed considerably during the early 1960s, although there was an uptake during the latter half of the decade, both to address attrition and an uptick in demand as the
Vietnam War intensified. Around this time, the aircraft was authorised for supply to friendly overseas operators under the
Military Aid for Assistance programme. Production of the T-37 was terminated in 1975. By this point, export sales of the type included 273 T-37Cs. Being derived from the T-37, the USAF had determined that a prospective COIN model would need to be able to carry a far greater payload, have more
endurance, and possess better short-field performance. Specific alterations made included the adoption of strengthened wings, the use of larger wingtip fuel tanks of capacity, additional avionics suitable for battlefield communications, navigation, and targeting, toughened
landing gear that were suitable for rough-field operation, and the fitting of a
General Electric-supplied
GAU-2B/A "Minigun" Gatling-style machine gun capable of a rate of fire of 3,000 rounds/minute and 1,500 rounds of ammunition that was installed in the aircraft's nose along with an accompanying
gunsight and
gun camera. Three
stores pylons were installed on each wing that were compatible with various munitions. This A-37 would not only be used in frontline combat in Vietnam, but was also exported to various other air forces, including several South American nations. Cessna proposed a number of innovative variants of the T-37 that never went into production. In 1959, Cessna built a prototype of a light jet transport version of the T-37, designated the Cessna
Model 407, which was stretched to accommodate a four-place pressurized cockpit with an automobile-type configuration. Only a wooden mockup of the Model 407 was constructed. The project was cancelled due to insufficient customer interest. The company also proposed a similar four-place military light transport, the
Model 405, with a large clamshell canopy, but it was never built. In response to a
United States Navy "Tandem Navy Trainer" (TNT) requirement, Cessna proposed a T-37 with a modified fuselage featuring a tandem cockpit. The Navy selected the
North American T-2 Buckeye, instead. Cessna proposed various other trainer derivatives for the US Navy and USAF, including a
vertical takeoff version based on the TNT configuration and incorporating lift-jet pods in the wings, but none of them reached the prototype stage. ==Operational history==