Fiat G.55 Centauro

By 1941 the Regia Aeronautica had learned a hard lesson: its nimble but lightly armed and underpowered fighters could not match the latest Allied types. The answer was the 'Serie 5' — a generation of fighters built around the powerful German Daimler-Benz DB 605 inverted-V12, built under licence by Fiat as the RA.1050 Tifone.

Fiat's chief designer Giuseppe Gabrielli drew the G.55 Centauro around this engine. First flown in April 1942, it joined the Macchi C.205 Veltro and Reggiane Re.2005 Sagittario as the three 'Serie 5' fighters — and of the three the G.55 was the largest, the most heavily armed, and arguably the best all-rounder.

The DB 605A delivered around 1,475 hp, pushing the Centauro to roughly 620 km/h at altitude with a service ceiling near 12,700 m — figures that finally let an Italian fighter meet Spitfires, Mustangs and heavy bombers on equal terms, especially at the high altitudes where earlier Italian types had struggled.

Armament was heavy and well-arranged. The definitive G.55/I carried three 20 mm MG 151/20 cannon — one firing through the propeller hub, one in each wing — plus two 12.7 mm Breda-SAFAT machine guns in the cowling. This concentrated, hard-hitting battery made it far deadlier against bombers than the two-gun fighters that had preceded it.

In February 1943 the Luftwaffe sent a technical commission to Italy under Oberst Petersen to fly the new Italian fighters against its own. At Guidonia the Bf 109G-4 and the Fw 190A-5 were flown in comparison with the three Serie 5 machines, and the Germans came away rating the G.55 the best of everything on the field — singling out its stability and controllability at every altitude, the quality that mattered most in a high-altitude interceptor and the one Italian fighters had most conspicuously lacked.

The line usually quoted is a remark attributed to Göring, that the Centauro was the best Axis fighter of its day; it is repeated everywhere and almost never with a source, and it is not needed. The commission’s own verdict is on the record and says the same thing with more authority, because Petersen’s pilots had no reason whatever to flatter an Italian design, and the practical consequence followed at once: Germany opened a study into building the G.55 under licence for the Luftwaffe.

The Centauro entered service in the summer of 1943, first flying in the defence of Rome and southern Italy against USAAF heavy-bomber raids. In these high-altitude interceptions its DB 605 engine and three-cannon battery made it the most effective Italian fighter available, credited with a number of B-17 and B-24 kills.

The gap between the verdict and the reality is the whole story of the aeroplane. On 8 September 1943, the day of the armistice, the Regia Aeronautica had taken delivery of 35 Centauros. The fighter that a German commission had just rated the best in the Axis existed, in the air force that ordered it, in thirty-five examples.

The armistice then split even those. In the south a handful flew on with the Italian Co-Belligerent Air Force alongside the Allies; in the German-occupied north the larger share went to the Aeronautica Nazionale Repubblicana, which fought beside the Luftwaffe over Italy until 1945. The same aircraft type, in the same year, carried the roundels of both sides of the same war.

Production continued in the north under German control, and the ANR received 148 more Centauros. They equipped units including the Squadriglia Montefusco and the 2° Gruppo Caccia in the defence of northern Italy, flying against American heavy bombers and their escorts in a campaign nobody expected them to win.

When the Fiat plant was finally taken, 37 more aircraft stood finished and 73 were on the line in various stages of assembly. Wartime production is usually totalled at 274 — a figure that includes the 35 of the Regia Aeronautica and the ANR’s 148, and that authors put lower when they count only aircraft actually delivered to units.

The Centauro’s fate was decided on the factory floor rather than in the air. It was an expensive aeroplane to make, needing roughly three times the man-hours of a Bf 109G, and Fiat’s Turin works lay under the Allied strategic bombing offensive for the whole of the period it was meant to be building them.

That figure also killed the German licence plan. Retooling costs time that a country losing a war does not have; German industry was committed to the Bf 109 and the Fw 190; and the DB 605 engines the G.55 needed were the same engines those two fighters were consuming. The study that began after Guidonia was dropped, and Germany chose instead to standardise the aircraft it already knew how to build fast.

Fiat’s answer was to fit a bigger engine. The G.56 was the Centauro rebuilt around the DB 603A, and two prototypes began flight testing in March 1944. Official maximum speed was 685 km/h, and on 30 March the test pilot Valentino Cus recorded between 690 and 700 km/h. In comparative flying it beat the Bf 109G, the Bf 109K and the Fw 190A, out-turning all of them.

It was never allowed to enter production, and the reason was stated plainly: the supply of DB 603 engines was limited and every one of them was earmarked for German designs. An occupied ally had built a fighter that beat the occupier’s newest types, and the occupier had the deciding vote on whether it could be made. Other developments went the same way — a G.55/II with five 20 mm cannon and a torpedo-carrying G.55S were both drawn and neither reached a squadron.

The design outlived the state that ordered it. With DB 605s gone, Fiat put the Rolls-Royce Merlin into the airframe as the G.59, first flying a Merlin-engined conversion in early 1948 and building just under 200 of all types, single- and two-seat. The wartime engine survived a little longer in the post-war G.55A fighter and G.55B two-seat trainer.

Argentina was the largest customer, taking around 30 G.55A and about 15 G.55B in the late 1940s; the Italian air force bought nine fighters and ten two-seaters; roughly 17 ex-Argentine Centauros went to Syria in 1948, and Syria later ordered 30 new-build G.59s. Counted together, the post-war airframes very nearly equal the 274 built during the war.

The Fiat G.55 came out of the German comparative trials as the finest of the Serie 5 — fast, strong, heavily armed and effective at the altitudes where the air war was being decided. What it never got was a factory. Design quality was not the constraint on the Regia Aeronautica; production was, and the Centauro is the cleanest proof of it in the whole Italian record.

The numbers make the point without needing an adjective. 274 were built in three years of war, against tens of thousands of the Bf 109 and Fw 190 it matched in the air, and 35 of them were in service on the day Italy left the war. Then Fiat put a Merlin in it and sold nearly as many again to Argentina, Egypt and Syria, where the last of them flew into the 1950s.

• Chris Dunning, Courage Alone: The Italian Air Force 1940–1943 (Hikoki Publications).
• Jonathan W. Thompson, Italian Civil and Military Aircraft 1930–1945 (Aero Publishers).
• Nino Arena, L’Aeronautica Nazionale Repubblicana 1943–1945 (STEM Mucchi).
• Gregory Alegi, Fiat G.55 Centauro (Ali d’Italia) — for the Guidonia comparisons and the production figures.