Everyone knows the Lockheed A-12 and its famous descendant, the SR-71 Blackbird — the black, Mach-3 spy planes that outran every missile ever fired at them. Almost nobody remembers the aircraft that nearly beat them to the job: Convair’s Kingfish, an angular, radar-dodging spy plane that lost the most important design contest of the Cold War by a whisker, and then vanished from history.

Yet the Kingfish may have been the more prophetic design. Two decades before the F-117, its creators were already shaping an aircraft to be invisible to radar — and that idea would outlive the contest it lost.

The race to replace the U-2

After a U-2 proved it could be tracked over the Soviet Union, the CIA launched Project GUSTO to find a successor that radar could not see. Two giants competed: Lockheed’s Skunk Works, under Kelly Johnson, and Convair of Fort Worth. Lockheed’s answer became the A-12 Oxcart. Convair’s was the Kingfish.

Convair took radar cross-section seriously in a way that was decades ahead of its time. The Kingfish buried its two Pratt & Whitney J58 engines inside the fuselage, used ceramic and radar-absorbing materials on its edges, and wore an angular shape that looks startlingly like the stealth aircraft of the 1980s. On paper it cruised at Mach 3.2 above 90,000 feet.

A rivalry decided by reputation

Kelly Johnson was not impressed by his rival — or rather, he was suspicious of how Convair had chased a small radar signature. In his classified log of the OXCART programme, he was blunt.

On 28 August 1959, the panel chose Lockheed. The A-12 was rated slightly faster and higher, and — crucially — cheaper. But the deciding factor was trust. Some CIA officers actually preferred the Kingfish for its smaller radar signature; they were talked out of it by the Air Force members of the panel, who remembered Convair’s troubled, over-budget B-58 bomber programme.

The Kingfish was never built. Funding dried up the moment Lockheed’s design succeeded, and Convair’s angular spy plane became a footnote. But look at an F-117 Nighthawk — buried engines, faceted skin, radar-absorbing edges — and you are looking at an idea Convair had first. It lost the contract. It may have won the argument.

Sources: Pedlow & Welzenbach, CIA history of the U-2 and OXCART Programs; Kelly Johnson, OXCART programme log; Wikipedia.