When Britain and France announced in 1962 that they would be working together on the Concorde supersonic airliner, the US was stunned. America’s best aviation engineers had been working on designs for exactly this type of cutting-edge high-speed passenger aircraft for more than a decade and they weren’t about to let some European upstart steal their thunder.

Therefore, President John F. Kennedy launched the National Supersonic Transport Program in 1963 to develop an all-American airliner able to fly at up to Mach 3.

This drew upon and resulted in some of the most audacious, ambitious and technologically advanced aircraft designs ever conceived. Many remarkable proposals were drafted, ranging from twisted and almost organic-looking oddities to brutally angular speed machines, some utilising the forms of existing supersonic military aircraft, others being entirely and stunningly novel. 

As these designs were studied, refined and tested, practical shapes and configurations took centre stages – such as Lockheed’s elegant L-2000 and Boeing’s swing-wing Model 733. The latter would emerge as the winner, losing its swing and becoming the Boeing 2707 – only for the whole programme to come crashing down amid worries about sonic booms and commercial viability. 

Dozens of these incredible designs, many of them previously unknown, are illustrated in US Aviation Secret Projects 4: America’s Concorde, with aerospace engineer Scott Lowther charting the dizzying rise and spectacular fall of the aircraft meant to transport Americans into a high-tech age of streamlined supersonic commercial flight.