” 500 km/h is already passé; in a few years, it will be common to all planes. We are so sure of it that we are looking even further… (Italo Balbo, 1931). This declaration perfectly recaps the spirit which brought about, a few years later, the first Italian jet. Since 1931, Secondo Campini, an aeronautical engineer, had shown to the Ministry of Aeronautics his studies of a new kind of engine, which promised higher speed and greater elevation. In brief, the schema proposed called for the dynamic collection and compression of air, which, subsequently, would be further compressed by a mechanical device, heated and then expanded through a jet to generate thrust.
In February 1934, the “Regia Aeronautica” stipulated a contract with Campini for the realization of two jet airplanes. For the construction of his machines, Campini contacted the firm “Aeroplani Caproni” of Taliedo, whose owner had been a believer in this new kind of propulsion since the beginning. The production of the first two prototypes began immediately, but was delayed mostly due to the unavailability of the aeronautical engines used to propel the compressor, and by increasing costs. The first prototype was not completed until 1940.
These delays caused the German Henkel He.178V1 to become, on August 27, 1939, the first jet plane in the history of aeronautics. Campini-Caprini prototype number one called for a propulsion system capable of dynamically collecting and compressing air via the movement of the airplane itself. Subsequently, air was further compressed using a three-stage axial compressor mechanically operated by an internal combustion engine (Alfa Romeo Asso L.121 RC40 900Hps). Upon exiting the compressor, air was heated by external burners and then allowed to expand through a Bernoulli jet. This device was adjustable by means of a “never-ending screw” of the Pelton type; the total thrust was about 750 Kg.
In reality, this propulsion system was still quite rudimental because the air was heated by a series of burners placed outside the jet. For better performance, these burners should have been placed inside the combustion chamber, thus allowing the air-gasoline mix to burn internally and not externally. Another substantial limitation was the fact that an auxiliary combustion engine actuated the three-stage compressor, and not, as usually found in similar engines, by a turbine directly connected and actuated by the exhaust gases. Naturally, this second choice would have caused substantial difficulties in terms of the proper material to be used by the turbine itself due to the extreme heat.
The prototype which flew for the first time on August 27, 1940 was an elegant monoplane with two seats wholly constructed of metal with a low wing of elliptical shape. After a series of tests and demonstration flights, the first prototype was transferred in November 1941 from Milan to the “Centro Sperimentale” in Guidonia, near Rome.
Test flights continued until 1942 when the plane was abandoned and later mined by the retreating Germans. The relic was examined by the British, sent to England and later scrapped. The second prototype, which left the assembly line in 1941 and had flown only once, survived the war and is currently preserved in excellent condition at the “Museo Storico dell’Aeronautica” in Vigna di Valle, just north of Rome. The Campini-Caproni jet plane was an aircraft of modest performance because of its excessive weight and the propulsion solution chosen. It never passed the prototypical stage but still represents a testimonial to a fascinating but unlucky technological gamble.