Vietnam War In August 1967, 25 A-37As were deployed to Vietnam under the "Combat Dragon" evaluation program, and flew from
Bien Hoa Air Base on USAF "air commando" missions, including
close air support,
helicopter escort,
FAC, and night
interdiction. The most noticeable problem was that the aircraft lacked range and endurance. Other concerns were heavy control response during attack runs (the flight controls were not power-boosted) and the vulnerability of the aircraft's non-redundant flight control system. Some pilots also criticised the machine gun as ineffective and negatively impacting the pilot's view. , California|alt= The USAF signed a contract with Cessna in early 1967 for an improved Super Tweet, designated the "A-37B". The initial order was for 57 aircraft, but this was quickly increased to 127; the unit cost of these aircraft were roughly one quarter of the
McDonnell Douglas F-4 Phantom II all-weather fighter aircraft. The A-37Bs were primarily intended to be supplied to the
Republic of Vietnam Air Force (RVNAF) as replacements for their
A-1 Skyraiders. The A-37B prototype was rolled out in September 1967, with deliveries to the South Vietnamese beginning in 1968. The A-37Bs were all newly built airframes that were considerably stronger than those of the A-37A, capable of pulling six
g instead of five, and were built to have a longer fatigue life of 4,000 hours. Field experience would demonstrate that 7,000 hours between overhauls could be tolerated. The A-37B weighed almost twice as much as the T-37C; a remarkable fraction of the loaded weight, , could be external stores. In practice, the A-37B usually operated with at least two and sometimes four underwing fuel tanks to improve combat endurance. The A-37B added a refueling probe to the nose, leading to pipes wrapped around the lower lip of the canopy, for probe-and-drogue
aerial refueling. This was an unusual fit for USAF aircraft, which traditionally are configured for boom refueling. Other improvements included updated avionics, a redesigned instrument panel to make the aircraft easier to fly from either seat, an automatic engine inlet
de-icing system, and revised landing gear. Like its predecessors, the A-37B was not pressurized. In order to accommodate the increased weight, the A-37B was powered by General Electric J85-GE-17A engines, providing thrust each. These engines were canted slightly outward and downward to improve single-engine handling. Air commando pilots in Vietnam operating the A-37A had found single-engine cruise an effective means of improving their flight endurance. Modifications were made to control surfaces to improve handling. To improve aircraft and crew survivability, the A-37B was fitted with redundant elevator control runs that were placed as far apart as possible. The ejection seats were armored, the cockpit was lined with nylon flak curtains, and foam-filled
self-sealing fuel tanks were installed. To extend endurance, pilots were authorized to fly the A-37 on only one active engine, an uncommon practice outside of emergency situations at that time. in nose compartment The
GPU-2/A and AMD cannon pods were tested with favorable results on the A-37B, but reports indicate that such pods were either seldom or never used in operation. The A-37 proved to excel at the close air support mission. It was able to engage targets at speeds roughly 100 miles per hour slower than swept-wing fighters and by doing so improve its bombing accuracy; pilots were reportedly able to achieve an average accuracy of . While the aircraft's slow speed was feared to make it more vulnerable to hostile ground fire, the A-37's relatively small size, atypical speeds, and relatively low altitudes combined to make it somewhat hard to effectively hit with gunfire. The A-37 did not typically attract attention from the media, unlike many other USAF combat aircraft used in the theatre; one reason for this was that the type was never flown into North Vietnam, where hostile air defenses were proved to be challenging, claiming to have downed almost 200 F-4s and 300 F-105s by the conflict's end. Instead, A-37s operated in the south, as well as in neighboring
Laos and
Cambodia, where it was typically used to support US ground forces. As a consequence of the North Vietnamese capture of
Da Nang Air Base at the end of March 1975, their forces captured large amounts of stores and equipment, including 33 intact A-37s. On 28 April 1975, several of these captured A-37s were used by the North Vietnamese
to attack Tan Son Nhut Air Base, still held by the South Vietnamese.
Post-Vietnam era Approximately 187 A-37Bs are believed to have been in RVNAF service by the Fall of Saigon in April 1975. Ninety-two of these were recovered by the US, while the other 95 aircraft would be operated by the
Vietnam People's Air Force in missions over
Cambodia and during the
China conflict in 1979. These "renegade" aircraft were phased out of service in the late 1970s or early 1980s, likely due to the lack of spare parts. Some of these captured A-37s were shipped to Vietnam's then-
Communist allies such as
Czechoslovakia,
Poland, the
Soviet Union and
East Germany. Others were sold to private foreign owners; six A-37B became the property of American warbird fans while four A-37Bs became privately owned by individuals in
Australia and
New Zealand. Following the conflict's end, the USAF opted to transfer their A-37Bs from the USAF
Tactical Air Command (TAC) to TAC-gained units in the
Air National Guard and
Air Force Reserve. During the early 1980s, these aircraft were assigned to the FAC (Forward Air Control) role and given the designation
OA-37B. The OA-37Bs were eventually phased out in the 1980s and 1990s and replaced in the FAC mission by the much more formidable
Fairchild Republic A-10 Thunderbolt II in USAF, Air National Guard, and USAF Reserve service. OA-37s from the
24th Composite Wing's (later
24th Wing's)
24th Tactical Air Support Squadron (
24 TASS) also saw service during
Operation Just Cause, the United States invasion of Panama in December 1989.
Salvadoran Civil War A-37Bs were used extensively by the
Salvadoran Air Force during the
Salvadoran Civil War, supplied by the United States in 1983 as a replacement for the Salvadoran Air Force's
Dassault Ouragans, several of which had been destroyed on the ground by the
FMLN. A-37Bs were used to bomb rebel bases, columns, towns, provided close air support, and flew interdiction missions. A total of 21 A-37Bs and 9 OA-37Bs were supplied during the war, one of which was lost on November 18, 1989 when fire from a
Dragunov sniper rifle killed the co-pilot, causing the pilot to eject, and another that was shot down by an
SA-7 missile on November 23, 1990. Nine A-37s remained in operational condition by the end of the war.
Other Latin American countries The A-37B was also exported to Latin America, mostly during the 1970s. It was well suited to their needs because of its simplicity, low cost, and effectiveness for insurgent warfare. Most of the A-37Bs exported south had the refueling probe shortened to act as a single-point ground refueling probe, or deleted completely. During the late 1970s, amid rising tensions between
Argentina and
Chile over conflicting territorial claims, commonly referred to be as the
Beagle conflict, the
Chilean Air Force retrofitted their T-37s into an armed configuration near identical to that of the A-37. In anticipation of a need for additional combat aircraft, the service subsequently procured A-37s from the United States as well. The
Guatemalan Air Force flew the A-37 in extensive counter-insurgency operations throughout the 1970s-1990s, losing one aircraft in action in 1985. The type has also been widely used for counter-narcotics operations. During the mid-1970s, 36 A-37Bs were procured for the
Peruvian Air Force. On 10 February 1995, a Peruvian A-37 was shot down by an
Ecuadorian Air Force IAI Kfir over a border dispute. On 20 April 2001, a Peruvian A-37B
shot down a civilian
Cessna A185E floatplane with a
minigun under surveillance by CIA controllers who advised against engaging—-according to the story version created by the CIA to cover their violation of Presidential conditions on their conduct. The Peruvian controller had the final authority in this situation, and he believed that the flight was
carrying drugs out of the country, and so ordered the A-37 pilot to open fire. (See author Tim Weiner’s explanation in his book The Mission). As a result a US missionary and her daughter were killed. The Cessna A185E crash landed in a river where locals in their boats helped the passengers. ==Variants==