One of the World's Earliest Jets
Not everybody really knows that Italy was the world's second country to launch a jet after Germany. That jet was the Campini-Caproni CC-2, of which the Milan Museum of Science houses the fuselage for static tests, and the engine. A complete aircraft of this type is preserved at the Aeronautical Museum of Vigna di Valle in the Rome area.
Ing. Campini
Soon after graduating from university in 1929, Bologna-born Ing. Secondo Campini set about studying jet propulsion, and published an article in the periodical, Rivista Aeronautica, on its prospective application to aeronautics. In 1931, Ing. Campini submitted a report on his propulsion system to the Italian Air Ministry. In the same year, he founded the V.E.N.A.R. (jet aircraft and watercraft) company, which was the world's first reaction engine manufacturer. Again in 1931, thanks to the support given by the Milan Riva company, he built the world's first motorboat propelled by water-jet drive. Water was collected and piped to a centrifugal pump featuring a double-throw spiral. The pump, which was driven by a 9 hp Isotta Fraschini engine, directed water through two adjustable needle nozzles, which could then be used as a helm. This motorboat attained the speed of over 28 knots in Venice, where it was tested in 1932.
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The CC-2 aircraft undergoing a ground test
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On 5 February, 1934, the Italian Air Ministry and Ing. Campini signed a contract to build two jets and one fuselage for static tests. As the company of Ing. Campini did not have the means to implement its designs, it affiliated with the Caproni company of Taliedo. But the former was solely responsible for the supervision of the work for the plan and construction of the aircraft. Tests led Ing. Campini to work on a United States patent in order to make another jet, which unfortunately was never built. The 31st/12/1936 deadline set for the submission of the prototypes was missed because of technical difficulties and rising costs. This led the Air deputy-minister, Mr. Valle, to grant
an extension. So it was that a fuselage for static and engine tests - which is now housed at the Milan Museum of Science - was completed. This fuselage provided static thrust for 700 kg. Two prototypes nos. M.M.487 and M.M.488 of the Campini-Caproni CC-2 aircraft were then made. Ing. Campini's prototypes in progress included a two-jet aircraft flying in stratosphere, and an autogiro. They were named S.C.3 and S.C.5 respectively - their modified versions being named, S.C.4 and S.C.6 respectively -. The autogiro was a two-seater jet-propelled helicopter, whose all-up weight was 500 kg. By going round, its rotor blades generated high speed and dynamic pressure, thus actuating the ramjet engines which were fixed to their ends. A 120 hp engine produced the power required to activate the ramjet engines. These plans, however, were never to be implemented because of the war.
The CC-2 Aircraft Flies!
On 27 August, 1940, the first prototype was tested for 10 minutes over the Taliedo airfield by the great pilot, Mario De Bernardi. On 16 September that same year it was flown for another 5 minutes, thus undergoing the acceptance flight test in order that the second prototype was upgraded. The latter made its maiden flight on 11 April, 1941. On 30 November, 1941, at 2:47 pm, Mario De Bernardi and Ing. Giovanni Pedace flew the second prototype on an official flight from the airport of Milan Linate and that of Rome Guidonia. After flying over Pisa, they landed at 4:58 pm after covering 475.554 km at the average speed of 217.147 km/h. According to the pilot's wish, the afterburner was never actuated in order to save fuel.
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The Caproni aircraft undergoing an acceptance flight test
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The flight was a tremendous success, su much so that Mussolini personally complimented De Bernardi, and low-altitude flights were made over Rome, preceded by announcements repeatedly broacast by radio. The event took the world by storm, and no less than 33 countries congratulated the Italian government. These flights were recognized by the F.A.I. (Fédération Aéronautique Internationale) to be the first ever made by a jet. Truth to tell, the plan conceived by the German, Hans von Ohain, and the Heinkel group, whereby the extraordinary He.178 aircraft was flown precisely a year before, on 27th August, 1939, had been kept secret.
Wartime and Postwar Years
In 1942, Ing. Campini was commissioned by the Italian Royal Navy two single-seater water-jet-propelled mini-submarines
(maximum power 1,000 hp; displacement 7 tons at the estimated speed of 30 knots; cruising radius 1,000 km). The prototypes
completed, fitted with the reaction engines, which had already undergone the acceptance flight test, were destroyed in 1944
by air raids. Other brainchildren of Ing. Campini, like a two-jet bomber and a fighter driven by the Campini-devised propulsion
system, were never implemented. De Bernardi and a panel of military engineers went on testing the CC.2 aircraft at the
experimental centre at Guidonia until September, 1942. However, the results were disappointing because of the limited overall
maximum power. So it was that the prototypes, having no further prospective developments, were stored in a hangar where
they were damaged by German air raids on 24 October, 1943. In June, 1944, the Anglo-American commission salvaged the
fuselage of the second prototype, and transferred it to the Royal Aircraft Establishment of Farnborough. After 1949, all trace
was lost of the second prototype. The first prototype, on the other hand, is now housed in the Aeronautical Museum of Vigna
di Valle, near Rome. The fuselage for static tests, and the reaction engine are on display at the Milan Museum of Science and
Technology.
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The prototype housed in the Aeronautical Museum of Vigna di Valle
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In 1948, Ing. Campini moved to the USA, where he conceived of a four-seater helicopter with a 200 hp turbine. In 1949, he carried out a new plan for a big helicopter with a rotor actuated by two turbines, which were capable of lifting a 40-ton armoured car. He received a commission by the American government to design a 6,000 kg-thrust long-range turbojet, and considered replacing the 4 propeller-driven engines of the Northrop YB-35 bomber with turbojets, and constructing the strategic bomber, B-49. Ing. Secondo Campini passed away in Milan on 7 February, 1980.
The Engine of the CC-2 Aircraft
Like a gun, which 'reacts' with a quick backward movement (i.e. the recoil) when a projectile is shot forward at high speed, a jet engine derives its thrust by reaction to its high-speed ejection of combustion products, and by the expansion of heated air, which is pushed out at a higher speed than when the air is drawn in. (After all, ordinary propellers work in a similar way. They accelerate backwards the air mass that moves through their rotating blades.) These introductory remarks are meant to help our visitors gain an insight into the workings of Ing. Campini's thermojet. It is, in effect, to be considered more as a hybrid than as a jet engine proper. An internal combustion engine characterized by reciprocating motion of pistons in its cylinder - in our case, a 900 hp Isotta Fraschini L. 121/R.C. 40 engine - drove a compressor incorporating 2 ducted propellers and a propeller designed to direct the flow and minimize the breakdown of the smooth airflow. A ring of injectors (i.e. the burners) introduced kerosine, whose combustion increased the volume of the thermojet and the exhaust velocity.
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Plan of the engine of the Campini-Caproni aircraft
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It was an interesting application, albeit structurally different from German turbojets - like those fitted to the Messerschmitt Me 262 aircraft - which, in place of the reciprocating engine, featured a turbine-driven air compressor. The turbine was to be found past the blast chamber, and the air under pressure was heated not through the injectors, but through several blast chambers that heated the air by conduction. Which was a more effective solution. What's more, the higher the altitude and speed, the better the performance of turbojets. On the other hand, endothermic reciprocating engines - like the one used by Ing. Campini - attain top efficiency at sea level, while they call for an extra compressor to operate at high altitude where the air is rarefied.
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Plan of the Jumo reaction engine of the Messerschmitt Me-262 aircraft
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The engine designed by Ing. Campini had many other drawbacks. That is, it was heavy and bulky, the type of engine used to drive the compressor was rather complex, the efficiency of the burner was low - although it came close to the best possible performance of the day -, and maximum power was considerably limited. This is why the German design - which came into use when World War II was drawing to an end, and was partly due to the British research work carried out in parallel - is the forerunner of the modern jet engines, while the Italian version has a purely historical value.
Technical Specifications
The Campini Caproni CC.2 aircraft is a single-propelled, tandem, two-seat, low-wing monoplane of all-duralumin construction.The wings are elliptical in plan. Other features include a pressurized cabin for altitude flight. The undercarriage is of the retractable type, the wheels rotating outwards during retraction into the wing thickness. The tail wheel retracts into dedicated fairing. The fuselage is of circular section structure. The rear section accommodates the exhaust pipe, complete with a cone for directing the flow of gases.
Other Data
Ducted fan with three rotors, of which two are rotating, and one is fixed; burners provide 700 kg thrust; engine of the compressor, 900 hp Isotta Fraschini L. 121/R.C. 40; length, 12.10 m; height, 4.70 m; span, 14.63 m; wing area, 36 sq m; weight empty, 3,640 kg; total weight, 4,217 kg; useful load, 577 kg; maximum speed at an altitude of 3,000 m without burner, 325 km/h; maximum speed at an altitude of 3,000 m with burner, 359.5 km/h; climb, 1,000 m in 9 min. (with burner); maximum altitude attained in the course of acceptance flight tests, 4,000 m.
Texts by Aldo Curti - Editing by Giuliano Gaia
We gratefully acknowledge the technical assistance of Ing. Mario Mantero.
For further, detailed information on Italian vintage aircraft you are referred to the periodical, Aerofan, published by Giorgio Apostolo, and to the book Gente dell'aria 2 by Giorgio Evangelisti published by Olimpia.
