The first Centauro to see operational use was the third prototype. On 21 March 1943, it was assigned to 20°
Gruppo (
squadron), 51°
Stormo (
wing) CT, based at
Roma-Ciampino, for operational evaluation. In May, the unit transferred to Capoterra, near
Cagliari having its baptism of fire on 5 June 1943 against Allied aircraft attacking
Sardinia. The two first pre-production series flew, respectively, on 10 April and in May 1943. In early June they were assigned to
353a Squadriglia (
flight)
CT based in
Foligno,
Umbria, were, until August, were transferred nine more aircraft. Pilots were delighted when they began to receive the new fighter in summer 1943. In June, the first Serie I were assigned to
Gruppo Complementare of 51°
Stormo in Foligno, near
Perugia, but in July the 11 G.55 of
Gruppo Complementare were transferred to 353a
Squadriglia, that already had in charge the "pre-series" machines, to operate from Roma-Ciampino Sud airfield. The 353a
Squadriglia, commanded by
Capitano Egeo Pittoni, flew many missions against the American bomber formations, but the flights were stopped when
Rome was declared "Città aperta" (
open city). On 27 August, the
Squadriglie 351a and 352a left Sardinia and arrived in Foligno to be re-equipped with G.55. But at the date of the 8 September the G.55 had not been delivered yet. During the first week of September, 12
Centauros had been assigned to 372a
Squadriglia of 153°
Gruppo in
Torino-Mirafiori. On 8 September 1943, the date of Armistice, the
Regia Aeronautica had received 35 G.55s. Only one of them flew to southern Italy, accepting the invitation of ''Maresciallo d'Italia''
Pietro Badoglio to surrender to Allied forces.
Service with the Aeronautica Nazionale Repubblicana There is no exact information about the G.55's captured by the
Luftwaffe or acquired by
Aeronautica Nazionale Repubblicana. About 18 G.55s were acquired by ANR while 12–20, or even 42, according to some reports, were requisitioned by the
Luftwaffe. It had three
Squadriglie (the 4th,
Gigi Tre Osei, the 5th,
Diavoli Rossi, and the 6th,
Gamba di Ferro). The unit operated near
Milan and
Varese until April 1944, then it was transferred near
Parma and
Pavia, then again near the
Lake Garda (
Brescia and
Verona). At the end of May, the 2°
Gruppo gave its G.55s to 1°
Gruppo and re-equipped with 46 ex I./JG 53 and II./JG 77 Bf 109G-6/R6 With the ANR, the G.55s gave a good account of themselves against Allied fighters, including the Spitfire and Mustang.
German interest In December 1942, a technical commission of the
Regia Aeronautica was invited by the
Luftwaffe to test some German aircraft in
Rechlin. The visit was part of a joint plan for the standardization of
Axis aircraft production. In the same time, some
Luftwaffe officers visited Guidonia, where they were particularly interested in the performance promised by the
Serie 5 fighters. On 9 December, these impressions were discussed in a
Luftwaffe staff meeting and raised the interest of
Hermann Göring himself. In February 1943, a German test commission was sent to Italy to evaluate the new Italian fighters. The commission was led by
Oberst Petersen; it was formed by
Luftwaffe officers, pilots and by technical personnel, among them
Flugbaumeister Malz. The Germans also brought with them several aircraft, including a
Fw 190 A-5 and a
Bf 109 G-4 for direct comparison tests in simulated dogfights. The tests began on 20 February 1943. The German commission very impressed by the Italian aircraft, the G.55 in particular. In general, all the
Serie 5 fighters were very good at low altitudes, but the G.55 was also competitive with its German opponents in term of speed and climb rate at high altitudes, while still maintaining superior handling characteristics. The definitive evaluation by the German commission was "excellent" for the G.55, "excellent" for the Re.2005 although very complicated to produce, and merely "average" for the C.205.
Oberst Petersen defined the G.55 "the best fighter in the
Axis" and immediately telegraphed his impressions to Göring. After listening to the recommendations of Petersen,
Milch and
Galland, a meeting held by Göring on 22 February 1943 voted to produce the G.55 in Germany. German interest, apart from the good test results, derived also from the development possibilities they were able to see both in the G.55 and the Re.2005. Particularly, the G.55 was bigger and heavier and was considered a very good candidate for the new, significantly larger and more powerful
DB 603 engine, which was considered too large to fit in the Bf 109's airframe. Other visits were organized in Germany during March and May 1943 in Rechlin and Berlin. The G.55 was again tested at Rechlin at the presence of Milch. Gabrielli and other FIAT personnel were invited to visit German factories and to discuss the evolution of the aircraft. The specifications of the German G55/II included the DB 603 engine, five 20 mm guns and a
pressurized cockpit. The suggestion of weapons in the wings, limited to one 20 mm gun for each wing, originated the final configuration of the
Serie I, while the DB 603 engine was successfully installed in what became the G.56 prototype. As a concrete expression of the German interest in the G.55, the
Luftwaffe acquired three complete G.55/0 airframes (MM 91064-65-66) for evaluations and experiments providing three DB 603 engines and original machinery for the setup of other production line of the Italian copy of DB 605. Two of the
Luftwaffe G.55's remained in Turin, at the
Aeritalia plants, where they were used by German and Italian engineers to study the planned modifications and the possible optimizations to the production process. Later these two were converted to Serie I and delivered to the ANR. The third one was transferred to Rechlin for tests and experiments in Germany. The DB 603 engines were used to build the G.56 prototypes. The interest in the G.55 program was still high after the Armistice. In October 1943,
Kurt Tank, who previously personally tested a G.55 in Rechlin, and who had had nothing but praise for the aircraft, was in Turin to discuss G.55 production. However, events in the war (including intention efforts by the Allies to bomb Italian aircraft factories) and the not yet optimized production process were the reasons for which the G.55 program was eventually abandoned by the
Luftwaffe. The aircraft's official maximum speed was 685 km/h (426 mph). It was armed with three 20 mm MG 151/20 cannon, one firing through the propeller hub while the other two were installed in the wings. It reportedly possessed excellent performance and proved to be superior to both the
Bf 109K and Bf 109G and Fw 190A, being capable of outmaneuvering all types during testing. Production of the G.56, however, was not allowed by the German authorities.
Postwar service During 1946, Fiat restarted production of the G.55, making use of the large stock of partly complete airframes and components remaining in its factories. It was available in two versions, the G.55A, a single-seat fighter/advanced trainer, and the G.55B, a two-seat advanced trainer, whose prototypes flew on 5 September 1946 and 12 February 1946 respectively. In September 1951, units of the
Argentine Navy and
Army attempted a
military coup against the government of
Juan Perón. The G.55s and the sole Argentine G.59 of
Grupo 2 de Caza of the Argentine Air Force attempted to defect to the rebel forces, flying to the
Punta Indio Naval Air Base. The pilots were arrested on arrival and the aircraft immobilised, however, and took no further part in the revolt, which was defeated by Loyalist forces.
G.59 The production of these orders for G.55s for Italy and Argentina caused the available stocks of the Italian licence-built version of the DB 605 engine to run short. As there was still a demand for the aircraft, it was decided to convert the type to use the more readily available
Rolls-Royce Merlin engine, with the first conversion flying in early 1948. The conversion was successful, and the AMI decided to convert its G.55s to Merlin power, these re-entering service at the
Lecce flying school in 1950 as the G.59-1A and G.59-1B (single- and two-seat versions). The AMI continued operating the G.59 until 1964.
Syria placed an order for 30 similar aircraft, which by this time, were completely from new production as the stocks of G.55 components had been exhausted. Of these, 26 were single-seaters (designated G.59-2A) and the remaining 4 two-seaters (G.59-2B). A single G.59-2A was acquired by Argentina for evaluation, but no further orders followed from the South American republic. The final versions were the G.59-4A single-seater and G.59-4B two-seater, which were fitted with bubble canopies for improved visibility. 20 G.59-4As and ten G.59-4Bs were produced by Italy. ==Variants==