The Cessna T-37 Tweet was the first purpose built jet trainer used by the US Air Force. It served served as the U.S. Air Force's primary pilot trainer for over 50 years. It was also modified to serve as a light attack aircraft for both the U.S. and other nations. In 2001 the Air Force began replacing the T-37 with the T-6 Texan II, a process that was completed in 2009.

The T-37 is a small, economical twin jet with side by side seating for a student and instructor.

Development

Origins

In 1952 the USAF issued a request for proposals for a "Trainer Experimental (TX)" program, specifying a lightweight two-seat basic trainer for introducing USAF cadets to jet aircraft.

Cessna responded to the TX request with a twin-jet design with side-by-side seating. The USAF liked the Cessna design since the side-by-side seating let the student and instructor interact more closely than with tandem seating. In of 1954, the USAF awarded Cessna a contract for three prototypes of the plane, and a contract for a single static test aircraft. The Air Force designated the type as XT-37.

The XT-37 had a low straight wing, with the engines buried in the wing roots, a clamshell-type canopy hinged to open vertically to the rear, a control layout similar to that of contemporary operational USAF aircraft, ejection seats, and tricycle landing gear. It first flew in October 12, 1954.

The wide track gear of the XT-37 and a steerable nosewheel made the aircraft easy to handle on the ground, and the short landing gear avoided the need for access ladders and service stands. The plane was designed to be simple to maintain, with more than a hundred access panels and doors. An experienced ground crew could change an engine in about a half hour.

The XT-37 was fitted with two Continental-Teledyne J69 -T-9 turbojet engines, French Turbomeca Marboré engines built under license, with 920 lbf (4.1 kN ) thrust each.

Tests showed the XT-37 had a maximum speed of 390 mph at altitude, with a range of 935 mi. The aircraft was unpressurized, limiting it to a ceiling of 25,000 ft by USAF regulations.

Production

The production T-37A was similar to the XT-37 prototypes, except for minor changes to fix problems revealed by the flight test program. The first T-37A was completed in September 1955 and flew later that year.

The Air Force liked the T-37A, but considered it to be underpowered; consequently they ordered an improved version, the T-37B, with uprated J-69-T-25 engines. The new engines provided about 10% more thrust and were more reliable. Improved avionics were also specified for the new variant.

A total of 552 newly-built T-37Bs were constructed through 1973. All surviving T-37As were eventually upgraded to the T-37B standard.

Due to a series of accidents caused by bird strikes, all T-37s were later retrofitted with a new windscreen made of half inch Lexan, which could tolerate the impact of a 4 lb bird at a relative speed of 288 mph.

The T-37A and T-37B had no built-in armament or pylons. In 1961 Cessna began developing a modest enhancement of the T-37 for use as a weapons trainer. The new variant, the T-37C, was intended for export and could be used for light attack duties if required.

The primary changes for the T-37C included stronger wings, with a stores pylon under each wing outboard of the main landing gear well. The T-37C could also be fitted with wingtip fuel tanks, each with a capacity of 65 gal, that could be dropped in an emergency.

The primary armament of the T-37C was the General Electric "multi-purpose pod" with a 12.7 mm (0.50 caliber) machine gun with 200 rounds, two 70 mm (2.75 in) folding-fin rockets, and four practice bombs. Other stores, such as folding-fin rocket pods or Sidewinder air-to-air missiles, could be carried.

T-37 production ended in 1975. The list of exports amounts to 273 T-37Cs. Adding this to the 444 T-37As and 552 T-37Bs gives a total of 1,269 aircraft built.

Significant Models

XT-37A

Two-seat jet trainer prototype aircraft, powered by two Continental YJ69-T-9 turbojet engines; two built.

T-37A

Two-seat basic jet trainer aircraft, powered by two Continental J69 -T-9 turbojet engines; 534 built.

T-37B

Two-seat basic jet trainer aircraft, powered by two Continental J69-T-25 turbojet engines, fitted with improved navigation and communications equipment.

T-37C

Two-seat basic jet trainer, light-attack aircraft, fitted with two weapons pylons, one under each wing; 269 built.