In February 1943 a German evaluation commission arrived at the Italian flight test centre at Guidonia with an Fw 190A-5 and a Bf 109G-4, and spent several weeks flying them against three new Italian fighters.

The head of the commission, Oberst Petersen, telegraphed Göring afterwards. His verdict on the Fiat G.55 Centauro was that it was the best fighter in the Axis.

Six months later Italy signed an armistice, and by then thirty-five had been delivered.

The Serie 5 competition

Italy entered the war with fighters that were beautiful, agile and hopelessly underpowered, because Italian industry could not build a competitive high-output inline engine. The answer, eventually, was to licence-build the Daimler-Benz DB 605, and three manufacturers designed fighters around it. These became the Serie 5.

The Macchi C.205 Veltro was the quickest to produce, being a re-engined development of an existing airframe, but its performance faded above eight thousand metres. The Reggiane Re.2005 Sagittario was the fastest at altitude and the best dogfighter of the three, and it was also plagued by vibration and required a ruinous amount of labour to build.

The G.55 came second on raw performance and won the contract anyway. It had the strongest airframe, the largest wing, the steadiest handling across the whole altitude band, and the heaviest armament with the deepest ammunition supply. It also had a known vice, a strong yaw to the left on take-off, partially cured by offsetting the fin.

What the Germans actually said

The Guidonia trials are the source of the G.55’s modern reputation, and the reputation is slightly bigger than the document.

Luftwaffe officers had visited in December 1942 and come away impressed enough that the matter reached Göring within days. The formal commission under Oberst Petersen, with Flugbaumeister Malz, began testing on 20 February 1943. The G.55 was rated excellent, the Re.2005 excellent but too complex to build, the C.205 average.

That line has been doing heavy lifting for eighty years. The written trials summary is more measured, and worth quoting properly, because it is a better description of the aeroplane than the telegram.

The same report also recorded that the G.55 was slower by 25 km/h, which the Germans attributed to the Italian-built DB 605 delivering around a hundred horsepower less than the German original; that the view from the cockpit was worse than on German types; and that aileron forces were high. Its conclusion was that the G.55 was the best Italian aircraft in the trials, which is a narrower claim than Petersen’s.

Even so, on 22 February 1943 a meeting chaired by Göring, with Petersen, Milch and Galland present, voted to put the G.55 into production in Germany. Kurt Tank flew one at Rechlin, was enthusiastic, and was in Turin that October to discuss manufacturing.

Why Germany did not build it

Arithmetic. An early G.55 absorbed something like fifteen thousand man-hours, against a target of nine thousand and an actual figure of around five thousand for a Bf 109. Germany in 1943 did not need a slightly better fighter that took three times as long to build; it needed volume.

Allied bombing settled the rest. A raid on Turin on 25 April 1944 destroyed fifteen completed G.55s. The three DB 603 engines the Luftwaffe had supplied for development went to Kurt Tank’s Ta 152C instead, and German production of the Centauro was quietly abandoned.

A short and awkward war

After the armistice the G.55 served with the Aeronautica Nazionale Repubblicana, the air arm of the German-backed Italian Social Republic, from November 1943. Ninety-seven of the 164 aircraft completed were built after the armistice, under German supervision, until production was stopped in September 1944.

The ANR units were then progressively forced to give up their Centauros and convert onto Bf 109Gs, a decision the Italian pilots resented and complained about, since most of them considered the G.55 the better aeroplane. Given the German trials report rated the two broadly comparable, they had a case.

The long afterlife

The interesting part is what happened next. Fiat restarted production in 1946 from leftover airframes, building the single-seat G.55A and the two-seat G.55B. The Italian air force took nineteen and ten respectively. Argentina bought thirty G.55As and fifteen G.55Bs, and in the anti-Perón coup attempt of September 1951 some of them tried to defect to the rebels and were impounded on landing.

Then the DB 605 stocks ran out. So Fiat re-engined the airframe with a Rolls-Royce Merlin and called it the G.59, which is a pleasing final twist: an Italian fighter designed around a German engine, finishing its career on a British one. The Italian air force flew G.59s at Lecce until 1964, nearly twenty-two years after the prototype first flew.

There was one more variant that never was. The G.56 fitted the larger DB 603A and reportedly out-turned both the Bf 109G and the Fw 190A in testing during 1944. Two were built. The Germans blocked it.

The Centauro is the clearest illustration of a problem that ran through the whole Italian war effort: the designs were competitive, and the industry behind them was not. Gabrielli produced an aircraft the Luftwaffe wanted to build under licence, and Italy managed 164 of them.

Sources: German comparative fighter trials report, Guidonia, February 1943, transcribed at ww2aircraft.net; Nino Arena, La Regia Aeronautica; Italian Air Force Museum, Vigna di Valle.