The T-37 first flew in 1954 as a basic jet trainer — forgiving, side-by-side and, thanks to its shrill turbojets, universally nicknamed the “Tweet.” In 1962–63 the USAF formally evaluated whether it could do counter-insurgency work, and awarded Cessna a contract for two prototype YAT-37D conversions. The changes were dramatic: General Electric J85 turbojets in place of the trainer’s little Continental engines roughly doubled the power; the structure was beefed up; hardpoints, a minigun, armour and wingtip tanks were added. The production A-37A followed in 1967 and the definitive, more powerful A-37B from 1968. Crews inevitably christened the muscled-up attacker the “Super Tweet” — a rare case of a frontline warplane that pilots had first soloed on as students.

For its size the Dragonfly was heavily armed. Built into the forward fuselage was a GAU-2B/A 7.62 mm minigun, a six-barrel Gatling gun typically fed around 1,500 rounds and able to saturate a target with fire. Under the wings, eight hardpoints carried a flexible mix of iron bombs, cluster munitions, rocket pods, napalm and gun pods, with a maximum external load commonly cited at roughly 2,300–2,600 kg. Permanent wingtip fuel tanks extended loiter time over the battlefield — important for close air support, where staying overhead to protect troops mattered as much as raw speed. In USAF service the type reportedly achieved an average bombing accuracy of about 45 feet, praised by the forward air controllers who directed it.

Because it worked low and slow over hostile ground, the A-37 was designed to absorb punishment. The B model added foam-filled, self-sealing fuel tanks, armoured ejection seats, nylon flak curtains lining the cockpit, and elevator control runs deliberately routed far apart so a single hit was less likely to sever both. During the 1967 Combat Dragon evaluation, the 25 deployed Dragonflies flew thousands of sorties and, by the most-repeated accounts, lost none to enemy fire — only two were written off in landing accidents. Over the whole war a relatively small number of USAF A-37s were lost to combat given the enormous sortie count, a record that reinforced its reputation for toughness.

The A-37 was prized above all for its economy, but precise dollar figures are hard to pin down. It was one of the cheaper combat jets of its generation — period accounts put the flyaway price in the low six figures in 1960s US dollars, though that should be read as an order-of-magnitude estimate rather than a sourced number. No reliable public cost-per-flight-hour figure exists for the type. What is well documented is the metric that mattered to the air forces that bought it: about two maintenance man-hours per flight hour, perhaps a sixth of what a contemporary fast jet demanded. Combined with its ability to fly from short, austere strips, that low running cost — not speed or sophistication — is the real reason the Dragonfly stayed in service for half a century.