Not everyone here was born with a copy of the Observer's Book of Aircraft clutched in his tiny fist, so some of our readers are probably wondering about the first aircraft in the Finmeccanica ad that appears in our sidebar. The one that looks like a cross between a WW2 fighter and the placid kind of seaplane that carries a bunch of fishing buddies to a remote lake in Canada.
It's the Macchi-Castoldi MC.72, the last, fastest and utterly baddest of the extraordinary seaplanes which, in the 1920s and early 1930s, raced for the Schneider Trophy, a large and fugly piece of metal which Jacques Schneider, a French armaments manufacturer, had donated as the prize in a series of seaplane races. To add a twist to the contest, Schneider had decreed that any nation winning three successive races would win the prize outright.
Britain, the US and Italy made most of the running. The US Navy dropped out after 1926, leaving a scratch team of enthusiasts in the RAF, the Air Ministry and British industry to face the Italians, who had been ordered to win the prize by Il Duce himself. After British victories in 1927 and 1929, the 1931 race would be Italy's last chance - with the UK aiming at 400 mph speeds and the Italians at 700 kmh (434 mph).
Rather than using exotic components and fuels to coax more power from a V-12 engine, designer Mario Castoldi and his colleagues at Fiat decided to use two engines - but without asymmetric-power problems or added frontal area. The AS.6 in the new MC.72 seaplane comprised two V-12s on a single crankcase, installed nose-to-nose with a reduction gear between them. Concentric driveshafts ran between the cylinder banks of the front engine, and turned two contra-rotating props.
That's where the fun really started. Wind-tunnel tests showed that the rear prop, driven by the aft V-12, could not absorb as much power as the front propeller because it ran in the latter's slipstream. The Italians' answer was to ground-adjust the pitch of the rear prop accordingly, and to use the surplus power to drive a common supercharger for both V-12 units, located at the back of the entire powerplant.
(At this point, you may hear an IC-engine engineer screaming OH NOOOOOOO!)
The result was an induction system that varied in length from a few inches on the aftermost cylinders, to seven-plus feet long at the front of the engine. And this before the days of fuel injection or high-octane fuel. The result on the first few runs was that half the engine was starved of fuel and the other half got too much. Vesuvian backfire hilarity ensued.
The engine was finally induced to run reliably on the bench and the MC.72 - essentially a flying radiator - started tests in August 1931. During the first high-speed runs, the backfiring started again, but as Capt. Giovanni Monti made a run past the engineers the vibrations destroyed a propeller bearing and the aircraft crashed - Monti never had a chance to escape. Weeks later, with a second aircraft, Lt Stanislau Bellini tried again - and shared Monti's fate as the engine blew itself to bits. A week later, the British took the trophy in a walkover.
The Italian team persisted in pursuit of the world speed record, which the UK had raised to 407 mph. The problem: the engine ran in static conditions, but tests hadn't simulated the effect of 400 mph-plus ram air into the system. With a lot of work - and some help from Rod Banks, the UK's famed fuel expert - pilot Francesco Agello tried again in 1934, setting a new record at 440 mph with the AS.6 pumping out 3100 hp at 3300 rpm - performance that would not be equalled for ten years when Britain's barbaric Napier Sabre VI howled over Northern Europe. Watch this, and listen to that engine sing: