How the “Super Tweet” Became an Unsung Hero of Vietnam

The Cessna A-37 Dragonfly, affectionately known as the “Super Tweet,” is a lesser-known, unsung hero of military aviation. Developed from the T-37 Tweet basic trainer aircraft, this light attack aircraft served with distinction throughout the Vietnam War under the United States Air Force.

It might not look as intimidating as its heavier counterparts, but the A-37 proved itself to be a remarkably effective combat platform. It particularly excelled in precision counter-insurgency operations where raw speed and payload weren’t as vital.

In the early 1960s, as American military involvement in Vietnam intensified, the need for specialized counter-insurgency (COIN) aircraft became increasingly apparent. The aging Douglas A-1 Skyraider, while effective, presented challenges for younger pilots accustomed to jet aircraft rather than radial-engine “taildraggers.” 

The Air Force’s Special Air Warfare Center at Eglin Air Force Base saw potential in the T-37 Tweet trainer as a promising COIN platform. The USAF determined the aircraft could be modified to effectively perform counter-insurgency missions. Cessna responded by essentially doubling the aircraft’s power, replacing the twin Continental J-69 engines with General Electric J85 turbojets capable of generating 2,400 pounds of thrust each.

In 1963, Cessna received a contract to produce two prototypes designated YAT-37D. These modified T-37s featured strengthened wings, larger wingtip fuel tanks, improved avionics, toughened landing gear for rough-field operations, and perhaps most importantly, a General Electric GAU-2B/A 7.62mm “Minigun” installed in the right side of the nose. Three stores pylons were mounted on each wing, allowing for a variety of munitions configurations.

The first YAT-37D completed its maiden flight in October 1964, followed by the second prototype a year later. Test results were positive, but ironically, the Air Force’s interest in counter-insurgency aircraft had begun to wane. The program stalled temporarily, with the second prototype actually being sent to the National Museum of the United States Air Force for display.

Fate intervened as combat losses of Douglas A-1 Skyraiders in Southeast Asia proved higher than anticipated. The YAT-37D suddenly looked attractive again, and the Air Force adopted an unusual approach—they’d evaluate the aircraft directly in combat. Cessna received a contract for 39 pre-production aircraft, initially designated AT-37D but quickly renamed A-37A.

Despite its small size, the A-37 packed quite a punch. The aircraft featured a 7.62mm General Electric GAU-2B/A minigun in its nose, capable of firing 3,000 rounds per minute with a supply of 1,500 rounds of ammunition. With eight pylons, the Dragonfly could carry up to 3,000 pounds of external munitions.

The A-37B model, developed after initial combat evaluations, weighed almost twice as much as the T-37C trainer it evolved from. A remarkable 5,800 pounds of its loaded weight could consist of external stores. To manage this increased weight, the “B” variant used more powerful General Electric J85-GE-17A engines, each providing 2,850 pounds of thrust.

Fuel tanks were fitted at the tip of each wing, and the A-37B incorporated a refueling probe for probe-and-drogue aerial refueling. This was an unusual configuration for USAF aircraft, which typically used boom refueling systems. The A-37B could reach speeds between 485-507 MPH, impressive for an aircraft of its class.

In August 1967, 25 A-37As arrived in Vietnam under the “Combat Dragon” evaluation program. Operating from Bien Hoa Air Base, they flew various missions including close air support, helicopter escort, forward air control, and night interdiction. Combat loads typically included high-explosive bombs, cluster munitions, unguided rocket packs, napalm tanks, and minigun pods. For most missions, aircraft carried additional external fuel tanks on their inner stores pylons.

The results were impressive. By December 1967, these A-37As had flown 3,000 missions without a single aircraft lost to enemy fire. 

The combat evaluation did reveal some limitations. Range and endurance were insufficient, control response during attack runs was heavy (as the flight controls weren’t power-boosted), and the non-redundant flight control system posed vulnerability concerns. Some pilots also criticized the effectiveness of the nose-mounted minigun.

To address these issues, Cessna developed the improved A-37B. The USAF quickly placed an order for 57 aircraft, and then increased that order to 127. These planes cost roughly one-quarter the price of a McDonnell Douglas F-4 Phantom II. At the time, that made them an exceptionally economical option for close air support operations.

The A-37 could engage targets at much lower speeds than swept-wing fighters. Pilots reportedly achieved average accuracies within a 45-foot radius of their targets. As one forward air controller remarked, “Thank God, now I have somebody who can actually hit the damn target.”

While some feared the aircraft’s slower speed would make it vulnerable to ground fire, its small size, unusual speed profile, and low-altitude operations actually made it difficult to target effectively. 

The A-37 required relatively little maintenance (only two hours of maintenance for each flight hour, six times less than what the McDonnell F-101 Voodoo required).

Following the Vietnam War, the USAF transferred their A-37Bs from the Tactical Air Command to Air National Guard and Air Force Reserve units. During the early 1980s, these aircraft were designated OA-37B and assigned to the Forward Air Control role. They remained in service until gradually being replaced by the more formidable Fairchild Republic A-10 Thunderbolt II.

The A-37 found extensive use in Central and South America, where its simplicity and effectiveness in counter-insurgency operations made it ideal for regional air forces. The aircraft was exported to many Latin American countries during the 1970s, including Chile, which retrofitted their T-37s to an armed configuration nearly identical to the A-37 during rising tensions with Argentina.

As of 2022, the A-37 Dragonfly remains in service with the air forces of Colombia, El Salvador, Guatemala, Honduras, Peru, and Uruguay.

The Cessna A-37 Dragonfly demonstrated that sometimes smaller, more agile platforms could outperform larger, more powerful aircraft in specific roles. Despite flying thousands of combat missions, the A-37 has been largely overshadowed in popular accounts of Vietnam’s “Heavy Metal” fighters like the F-4 Phantom II, F-100 Super Sabre, and F-105 Thunderchief.

Nevertheless, the “Super Tweet” earned its place in aviation history (and of course still sees continued service in several air forces decades after its introduction). For an aircraft that began life as a trainer, the A-37 Dragonfly proved remarkably adept at the business of war.