For anyone interested, here is a bit from my upcoming article in November's Aviation History (Advt.):
Mitchell insisted on the wings being both as thin and strong as possible, with low drag, superior maneuverability, mild stall characteristics and high speed capability — an apparent engineering conundrum even the brilliant Willy Messerschmitt never solved.
The resulting double-ellipse shape, largely the work of Beverley Shenstone, with a main spar of hollow sections slotted into each other, was exceptionally strong and had the low loading of 26 pounds per square foot (psf). The Messerschmitt Me 109’s was closer to 40 psf, allowing the Spit to out-turn it — a critical factor when either pursuer or pursued. Despite their thinness they could house eight machine guns (later, four 20mm cannons), ammunition belts, undercarriage, coolant and oil radiators, flight controls and other essentials.
The design was so advanced it could reach high Mach numbers. In 1943 Sq. Ldr. J.R. Tobin dove a Spitfire XI to an indicated airspeed (IAS) of 675 mph (Mach 0.92). Vickers test pilot Jeffrey Quill wrote: "That any operational aircraft off the production line, cannon sprouting from its wings ... could easily be controlled at this speed when the early jet aircraft such as Meteors, Vampires, F-80s etc. could not, was extraordinary," especially when almost nothing had been known in the 1930s about aircraft behavior at transonic speeds. (The Me 109’s controls tended to freeze in a high-speed dive, many unfortunate Luftwaffe pilots discovering this by “augering in.”)
And in 1951 Flt. Lt. Ted Powles flew a PR XIX to 51,550 feet, a world record for piston-engined aircraft. When cockpit pressurization began to fail, Powles had to lose altitude rapidly, reaching an IAS of 690 mph — Mach 0.94.
The Spitfire wasn't a great deal heavier than the legendary lightweight Japanese Zero, which had no bullet-proof windshield, armor, self-sealing tanks, starter motor or, usually, radio. In a moderate wind it could be airborne in 50 yards, while the heavy P-47 Thunderbolt needed closer to 500. Spitfire pilots on shared airfields would take off and perform rolls while the Thunderbolts labored to takeoff speed, an activity finally forbidden as contrary to good relations.
This eagerness to leave the ground contributed to one of the plane's enduring anecdotes. Flt. Lt. Neill Cox, DFC, unaware that WAAF mechanic Margaret Horton was still riding on the rear fuselage — normal procedure to keep the tail down when taxiing — gunned the engine and took off with Horton still clinging to the tail. Radioing that he couldn't trim for level flight, Cox was ordered to land, without mentioning his "passenger." He told the shaken but unharmed Horton: "put in a pay chit for ten minutes' flying time and I'll sign it."
