In 1931 Italian aeronautics engineer Secondo Campini submitted a report to the Regia Aeronautica (Royal Italian Air Force) on the potential of jet propulsion, with some proposals for its implementation. Later that year, Campini founded his own company to seek after both the development and practical applications of the jet engine. Accordingly, the next year he demonstrated a jet-powered boat in Venice, being that way the first vehicle to harness jet-propulsion and reached a speed of 28 knots during testing. This experiment attracted much attention from the Italian government, and shortly later Campini received a government-issued contract to produce a pair of engines for testing purposes.
During 1934 the Regia Aeronautica allowed the development of two prototypes together with a static testbed for the purpose of demonstrating the principle of a jet aircraft and explore its military applications. Considering that Campini's company lacked the needed industrial infrastructure for such endeavour, he reached an agreement with Caproni aviation manufacturer, under which they provided the needed material assistance for the manufacturing of the prototypes. Under this partnership Campini developed his design, which later received the official military designation of N.1.
Its development, unlike its German or British counterparts, was made totally public, because the Italian government wanted to give the impression that Italian industry was modern and sophisticated.
The Caproni Campini N.1 was an experimental aircraft, designed to demonstrate the feasibility of the jet engine. It was entirely out of duraluminium and had a monoplane layout, outfitted with an eliptical wing. The initial aircraft lacked certain elements like a pressurised cabin, however, that feature was included in the second prototype. However, after initial flight testing, it was found that the heat output generated by the pioneering propulsion system, the canopy had to be left permanently open as a heat mitigating measure.
The engine itself was different from the later jet engines. One radical difference was the compressor, a three-stage variable-incidence one, located forward of the cockpit, was driven by a conventional piston engine, which was a 900hp liquid-cooled Isotta Fraschini. The flow provided by the compressor was used to cool down the engine before being mixed with the engine's exhaust gases recovering that way most of the heat energy that in traditional piston-propelled designs would've been discharged overboard. A ring-shaped burner would then inject fuel into the gas flow and ignite it, just before the exhaust nozzle to further increase thrust.
The engine turned to be powerful enough to provide enought thrust for flight even without activating the rear burner, similar to a ducted fan coupled with an afterburner. Campini named this configuration as a "Thermojet", although with time it has been known as a "Motorjet". However, due to the small size of the duct, limited the mass flow and therefore the propulsive efficiency of the engine, resulting in relatively low pressure ratios with poor thrust and poor fuel efficiency. Ground tests of the engine yielded a thrust of around 700Kgf (1500Lbf.)
The maiden flight took place on 27th August 1940 in Taliedo, Milan at the hands of test pilot Mario De Bernardi, a veteran pilot who had previously set various aviation records. The initial flight took under 10 minutes, during which the speed was kept under 362 km/h (225mph) on purpose, due to insecurities about the untested frame. Considering that the German Heinkel He.178 had flown a year before, but it was kept as a secret, the Fédération Aéronautique Internationale recorded the event as the first successful flight of a jet aircraft.
Subsequent flight tests achieved the speed of 515 km/h (320mph). Anyway, testing revealed issues with the engine as it lacked the ability to provide enought thrust to achieve high performance.
Later, on 30th November 1941 the second prototype was flown by De Bernardi and engineer Giovanni Pedace from Linate Airport in Milan to Guidonia, in Rome, as a publicity maneouver. That was the first cross-country jet flight to occur and the first mail delivery performed by a jet powered aircraft. In that flight there was a stopover at Pisa for refuel and was made entirely without using the rear burner.
The N.1 served as a pioneer and jet demonstrator. After that November 1941 flight, a total of 33 nations, some of which at war with Italy at the moment, sent their official congratulations to Italy for the achievement, making the prototype successful.
Thanks to the experience gained with the N.1, Campini, partnered this time with Reggiane (another Italian aircraft manufacturer) and aircraft designer Roberto Longhi, commenced work on a completely new design including the decission of abandoning the native Italian jet engines in favour of its German counterparts, this aircraft, which was never completed was called Reggiane Re.2007.
The N.1 was kept testing well into 1943 when, due to the outcome of the war, and the Allied bombing campaign which destroyed Caproni's factory at Taliedo, one of the prototypes was destroyed and subsequent testing was cancelled. After the war, the N.1 was transported to RAF Farnborough were it was tested and later scrapped. Another prototype was kept in storage at Caproni's facilities, where it survived the war. During the 1950s it was sent to the Italian Aeronautica Militare (Italian Air Force) to be kept in the Italian Air Force's museum, where it's being showed today.
We've drawn also an entirely fictional single-seater fighter variant (with the cabin heat problem solved) which was armed with two 12,7mm Breda-SAFAT machine guns placed in the nose plus two additional 12,7mm ones placed in the wings.
Sources:
1. https://en.wikipedia.org/wiki/Caproni_Campini_N.1
2. https://it.wikipedia.org/wiki/Campini-Caproni_C.C.2 (translated)
3. Salamander Books - The Complete Book of Fighters
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