In October 1943, the British Ministry of Aircraft Production issued Specification E.24/43: build an aircraft capable of 1,000 mph at 36,000 feet. Miles Aircraft — a small firm best known for training aircraft — won the contract. What they designed was so far ahead of contemporary aerodynamics that when they shared it with the Americans in 1944, Bell Aircraft quietly redesigned the X-1 around it.

The Miles M.52 was the first aircraft ever designed from the outset to fly supersonically. Its features read like a 1955 spec sheet written in 1944:

• Bullet-shaped fuselage shaped after the .303 rifle round — the only object engineers knew for certain went supersonic without shredding itself
• Biconvex wings with a razor-thin 7.5% thickness-to-chord ratio, sharply tapered
• An all-moving tailplane ("slab tail") — the entire horizontal stabilizer pivoted, sidestepping the elevator control reversal that killed pilots in transonic dives
• A jettisonable, pressurized nose capsule with parachute recovery — history's first practical escape pod
• Powered by Frank Whittle's Power Jets W.2/700 turbojet with a rudimentary reheat/afterburner and augmentor tailpipe pushing 4,000 lbf

By early 1946 the first prototype was 82% complete at the Miles factory in Woodley. First flight was scheduled for later that year.

Then on February 12, 1946, Sir Ben Lockspeiser, Director-General of Scientific Research, cancelled the entire program. His stated reason: "the risks attending high-speed flights are too great to warrant the use of a manned aircraft." De Havilland's Geoffrey de Havilland Jr. would die seven months later in the tailless DH 108, seeming to vindicate the decision. It didn't. The M.52's whole point was that the all-moving tail solved the problem that killed him.

The real reasons were budgetary — the postwar Attlee government was slashing military R&D — and a disastrous 1944 technology-exchange agreement in which Britain handed the M.52's complete design data, wind tunnel results, and tail configuration to Bell Aircraft. The reciprocal American data never arrived. Bell engineers, who had been struggling with elevator lock-up on the XS-1, incorporated the all-moving tail. Chuck Yeager broke Mach 1 on October 14, 1947 using exactly that feature.

Vindication came a year later. A 30% scale, rocket-powered unmanned model of the M.52 — built by Vickers-Armstrong under Barnes Wallis — was launched from a Mosquito over the Scilly Isles on October 10, 1948. It reached Mach 1.38 in stable level flight. The design worked. Britain had just proven it on a shoestring, two years after cancelling the manned version.

Why revive the concept now? The M.52's core problem was materials and thrust — its aluminum airframe would have suffered kinetic heating at sustained Mach 1.5, and the W.2/700 was marginal. Both are solved:

• Titanium and carbon-carbon composites handle Mach 2+ skin temperatures routinely (F-22, Concorde legacy)
• Modern variable-cycle turbofans (GE XA100 class) produce 5× the M.52's thrust at half the fuel burn
• The all-moving tail is now standard on every supersonic fighter — the M.52 was right
• Small-team, single-purpose supersonic demonstrators (Boom XB-1, NASA X-59) are back in fashion; the M.52's Whittle-era simplicity and escape capsule are a template for cheap, safe supersonic research

Boom Supersonic's XB-1, which broke Mach 1 in January 2025, is essentially the aircraft the M.52 would have become had it flown — 78 years later.