By 1934, both teams had started to think about their monoplane designs when Camm and Mitchell received visits from Squadron Leader Ralph Sorley of the Royal Air Force's Operational Requirements Branch. He told them that the Air Ministry had been running tests on a firing range and had determined that it would require 266 hits from .303-caliber ammunition to lethally damage an all-metal bomber. The Air Ministry had further calculated that at a closing speed of 180 mph, a fighter would have two seconds to score. Thus, at 1,000 rounds per minute per machine gun, the new interceptor would need eight .303 Brownings to deliver a total of 266 rounds in a two-second burst. Could the designers squeeze eight guns into their interceptors?
The gun requirement was less of a problem for Camm's prototype Hurricane, which had wings thick enough to house four weapons apiece. But for Mitchell's thinner-wing Spitfire, the eight-gun requirement created a major problem. Beverly Shenstone, a Canadian aerodynamicist, had already convinced Mitchell that the Spitfire should have an elliptical wing, like the one on Germany's high-speed Heinkel He 70 airliner. Then considered the epitome of streamlined design, the He 70 had caused a sensation in British aeronautical circles. Such a planform would permit a speed-friendly, thin thickness-to-chord ratio (the ratio of wing depth to the distance from the leading to trailing edge) while still providing space sufficient to house the guns and retractable landing gear. But now, even this ellipse had to be broadened and skewed slightly forward to ensure that it could retain its thin section yet accommodate the additional weapons. Gone was a Heinkel-like symmetrical ellipse; in its place was the Spitfire's trademark pointy-tip shape.
The Hurricane flew for the first time on November 6, 1935. The first Spitfire flew four months later, on March 5, 1936. In June—not a moment too soon—the Air Ministry ordered 600 Hurricanes and 310 Spitfires. The first production Hurricanes began reaching squadrons in January 1938. The Royal Air Force didn't get its first service Spitfires until August 1938. The Second World War would begin 13 months later.
Time had already run out for Mitchell, who died in June 1937. Mitchell's successor, Joseph Smith, had the daunting job of transforming a prototype into an operational military aircraft. No one in Britain had ever mass-produced a fighter as advanced as the Spitfire. It took Smith and Vickers Supermarine a while to figure the process out, which is part of the reason that in the Battle of Britain, more Hurricanes flew than Spitfires. In 1940 there were just enough of each to hold off the Luftwaffe. To understand how close Britain (and the rest of the free world) came to defeat that summer, I had to see a Hurricane naked.
I went looking for one in the idyllic village of Milden, deep in the Suffolk countryside of eastern England. Milden is the home of Hawker Restorations Limited, which is the domain of Tony Ditheridge. Hidden behind a towering hedge on a narrow lane, Hawker Restorations comprises a compound of garages, workshops, and fields surrounding Ditheridge's 15th century moated farmhouse. "It's a listed building," Ditheridge says, meaning that before he can so much as dredge the moat, a historic preservationist has to come out for an inspection.
I had come in secret hopes of cadging a seat in a Hurricane cockpit, but Ditheridge broke it to me immediately: I was a week too late. He'd just dispatched an ocean-going shipping container housing the fuselage of a late-model Hurricane XIIB and a 40-foot cargo rack holding the airplane's wings. They were bound for the port of Seattle and Microsoft billionaire Paul G. Allen's Flying Heritage Collection in Arlington, Washington (see "Crown Jewels," Oct./Nov. 2004). Ditheridge had photographs of the Hurricane and of the motor crane that he'd rented to lift it over his front hedge and onto a flatbed lorry.
A seat in a Hurricane is rarer today than one in any old Spitfire: Over time, 22,129 Spitfires were built, versus 14,074 Hurricanes. Hawker Restorations welcomes every opportunity to preserve the scarce fighters. With the Seattle-bound Hurricane out the door, Ditheridge's shop crew had already filled the empty bay with a new restoration project.
As Ditheridge and I walked down to the shop, he told me how he made his fortune in the 1980s selling medical imaging systems around the world. In the 1990s he moved into aircraft reconstruction, combining his passion for flying with his knack for managing technologies, only this time it was the technologies of 1940s metal warplanes like Spitfires, Corsairs, and Mustangs. Along the way, Ditheridge was drawn into pre-World War I projects, restoring and replicating flying machines made of wood, wire, and canvas. From there, a jump to Hurricane technology was not too far.
To give me an idea of what some of his rougher projects look like when they arrive, we stop outside the shop so Ditheridge can show me his aluminum scrap heap. "Just imagine 2,000 pounds of this," he says, pointing to a three-foot-high mound of shredded, corroded sheet metal.
Inside the shop, three bare-bones Hurricanes are waiting. One look around is more enlightening than a thousand pages of Battle of Britain history. Though the modern eye might perceive them as a manufacturing nightmare, the Hurricane's mechanical joints would have seemed very familiar to aircraft builders in 1940, says Ditheridge. It was the Spitfire that gave them conniptions. The Air Ministry calculated that building a Spitfire took 15,200 man-hours but a Hurricane took only 10,300. Camm's old technology saved the day, at least in 1940.