Mosquito mothership and Mini-Miles during Operation NEPTUNE

‘One of those flashes of genius that can change the course of history.’

–Eric ‘Winkle’ Brown

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If General Hap Arnold was feeling at all jaded, the sight of the yellow-painted Mosquito, impressively displayed by its test pilot, Geoffrey de Havilland, raised his spirits. The previous night, on April 19, 1940, following dinner with Prime Minister Winston Churchill, the United States Army Air Corps Chief had been up talking until 2 am. This energy-sapping encounter did nothing to dampen his enthusiasm for de Havilland’s new twin-engined bomber, which he deemed to be ‘outstanding’.

Returning to the United States with a set of plans for the Mosquito, America’s own entry into the war was still eight months away. It would take until July 1943 before the USAAC, lobbied by the President’s son, Elliot Roosevelt, made a formal bid to acquire Mosquitos which, two years on, still outperformed any other machine in the sky. It was one of only three British designs, alongside the Spitfire and a small quantity of Beaufighters, supplied to the US under the reverse lend-lease agreement.

Accelerated by war, Britain’s aviation industry was world-leading, a position reinforced by machines like the magnificent Mosquito. Four years later, de Havilland’s finest would play a supporting role in the country’s retreat from the race.

Lieutenant Commander Eric ‘Winkle’ Brown’s introduction to the Mosquito came in 1944 when he was asked to land one on an aircraft carrier – the first time anyone had attempted to do so in a twin-engined machine. A Fleet Air Arm fighter pilot with a number of kills to his name, Brown was already building a reputation as Britain’s most revered test pilot, and would, in a long career, set records for both the greatest number of different aircraft types flown and more carrier landings than anyone else in history. Both still stand today. In December 1945 he also became the first person to land a jet aircraft on a carrier when recovered aboard HMS Ocean in a de Havilland Sea Vampire.

The following summer, however, he was expecting to become the first person to fly faster than the speed of sound.

Details of Britain’s early jet engine development, led by Frank Whittle, had been shared with Hap Arnold during his April 1941 visit to Britain. Enthused by its potential, the USAAC boss pushed for its adoption on his return to the US, only to conclude that, with war seemingly imminent, it was more important to build sufficient numbers of good aircraft than to choose to ‘follow the mirage’ that jet propulsion seemed to offer.

Across the Atlantic, Britain’s first jet, the Gloster W.28/39, took to the air just a month after Arnold’s visit. Work on the experimental jet in which Winkle Brown was going to break the sound barrier began the following year. Four years later, in February 1946, with construction of the prototype Miles M.52 already well advanced, the project was cancelled, and all of the company’s research was shared with the United States. With the end of the war, Winkle’s hopes of going supersonic were deemed to be unaffordable and unnecessarily risky.

The cockpit of the Miles M.52 after its cancellation

In the US, though, work on a rival design continued unabated. At first glance, the bullet-shaped, straight-winged Bell X-1 and Miles M.52 looked similar but, lacking a sufficiently advanced jet engine, Bell chose to use a rocket engine. And, on 14 October 1947, Captain Charles ‘Chuck’ Yeager, after being carried aloft in the X-1 by a B-29 Superfortress, dropped from the bomber’s belly, ignited the rocket and flew beyond Mach 1 for the first time.

Winkle Brown’s disappointment cut deep. Not least because he, along with many others who had worked on the M.52 project, was convinced the X-1 had only been controllable at transonic speeds because of its adoption of the all-moving tailplane pioneered by Miles’s design.

A year later, a Mosquito XVI took off from St Eval airfield in Cornwall to complete Operation NEPTUNE. Climbing to a height of 36,400 feet, she levelled off west of the Isles of Scilly and accelerated to near 400 mph. Beneath the fuselage, she was carrying a 3/10-scale, rocket-powered model of the Miles design.

With the cancellation of Winkle Brown’s attempt to fly faster than sound, the distinctive M.52 design had been adopted by Barnes Wallis at Vickers-Armstrong for a series of unmanned high-speed trials. The first of these NEPTUNE flights, launched six days before Chuck Yeager’s record-breaking flight over the Mojave Desert, ended in failure when the model’s rocket engine blew up. A year of frustration followed. But on October 10, 1948, it all came good.

The model’s Alpha rocket fired six seconds after being dropped from the Mosquito mothership. The Mini-Miles accelerated smoothly, trailing a slim white exhaust plume. Sixty-two seconds later, telemetry equipment recorded that the little drone was flying at Mach 1.38, proving the soundness of the original design.

The Mini-Miles in flight after being dropped from the Mosquito mothership

For Winkle Brown, the cancellation of the Miles M.52 and the success of Chuck Yeager’s Bell X-1 represented the moment that Britain relinquished its position at the forefront of global aviation. If that was the case, the Mosquito, a machine that remained unsurpassed for its performance and versatility throughout the war, had represented something of a high-water mark. And, even three years after the war’s end, it was still the only place to turn when a high-speed, high-flying aircraft capable of launching the Mini-Miles drone was needed.

And Winkle was an unabashed fan of de Havilland’s finest. The Mosquito, he wrote, was ‘one of those flashes of genius that can change the course of history.’ After losing the race to Mach 1, he could never quite bring himself to be similarly generous about Chuck Yeager …

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