Italian Whirlwind; The IMAM Ro.57

October 6, 2023

As my last article was on the Breda Ba.88 it seems that I am on a theme at the moment of “Italian aircraft that looked the part but just didn’t deliver”. Because in the IMAM Ro.57 we certainly have just that.

In 1938 the Italian Industrie Meccaniche e Aeronautiche Meridionali company (IMAM) identified that there might be a need in the near future by the Royal Italian Air Force for an aircraft type that most other major European countries were either actively fielding or planning on introducing – the twin-engine heavy fighter which could act as a long-range escort for bombers or as an interceptor.

IMAM had in fact already been working on a design for the same original 1936 requirement for a multirole attack fighter that had generated the Ba.88. But as IMAM was a part of Breda and the mother company’s design had already been selected, the design team decided that it might be prudent to not aggravate head office and so rapidly changed their design to meet the perceived new requirement a long-range fighter.

And considering that IMAM had originally been founded by Nicola Romeo in 1923 (the same guy who founded ALFA Romeo) before being taken over by Breda, I would say that the design team came up with a remarkably sleek aircraft that would have done the company’s founder proud.

I mean look at it. It looks like the sort of thing a cool 1930’s comic book hero would fly.

A sleek, low-winged monoplane flown by a single pilot, in appearance the Ro.57 is not entirely dissimilar to the contemporary Westland Whirlwind and Grumman XP-50.

The Ro.57 was constructed in a similar fashion to the Breda Ba.88, having a steel tube framework skinned in aluminium alloy. This build method was slightly anachronistic compared to other nations increasing use of full monocoque designs, which used stressed skin techniques to remove the need for the internal framework, generally providing a way to cut weight.

But despite this the Ro.57 was surprisingly light, weighing only 6,856lb (3,110kg) empty, which compares very well to the Whirlwind and the slightly later XP-50 which both came in at 8,310lb (3,769 kg).

In terms of powerplant, the Ro.57 was at a disadvantage to these other designs, using two Fiat A.74 radials that produced 840hp. In contrast the Whirlwind had liquid-cooled Peregrines that produced fractionally more power at 885hp, though were much more streamlined, while the XP-50s Wright R-1820s were considerably more powerful, producing 1,200hp each. But the A.74 was the best Italian engine available at the time, and the Ro.57 apparently performed pretty well in testing that the Italian Air Force conducted with the aircraft in late 1939.

The Ro.57 apparently handled satisfactorily, though was notably less agile than the primary Italian single-engine fighter of the time, the Macchi C.200, which to be fair is to be expected. However, it did have a slightly better top speed than the MC.200, clocking just over 320mph (516km/h) vs. the Macchi’s 313mph (503km/h), plus it had a considerably better range of 745 miles (1,200km),  about two-and-a-half times that of the single-engine fighter.

The principle concern was the poor armament of just two Breda 12.7mm machine guns in the nose. This is today seen as a missed opportunity as other aircraft in the Ro.57’s range generally had 20mm cannon, but in fact the fit was the excepted standard for Italian fighters at the time and so one assumes IMAM thought it would be suitable.

Regardless, despite the positive feedback the Ro.57 just sort of vanished for a couple of years, with the Royal Italian Air Force not following up with any initial production orders. Again, I suspect this had more to do with the need to build modern aircraft of all types and that Italian aircraft manufacturers were already working pretty much flat out in the run up to the Second World War, and thus the idea of building the long-range fighter that wasn’t designed to an official specification wasn’t seen as justified, especially when one remembers that every single Ro.57 built would use engines that could be used to build two conventional fighters.

In defence of the Italian air ministry, that would be a legitimate concern, especially with war looming imminently, though ironically, considering the situation that Italy soon found itself in waging campaigns across the expanses of the Mediterranean, North Africa and Russia, it seems that IMAM may have anticipated the need for a long-range fighter correctly.

But as it was the Ro.57 was essentially shunted aside and ignored until 1941. At that point the failures of the Breda Ba.88 had become horribly apparent, and the Royal Italian Air Force started desperately searching for something to fill the gap it had for an effective fighter bomber. So ironically the Ro.57 found itself shoehorned into the role it had originally been intended for, but which its redesign had left it rather unsuitable.

But it couldn’t be worse than the Ba.88, so IMAM was instructed to convert the design to become a dive bomber, with the new model being designated as the Ro.57bis.

This saw the aircraft altered to include dive brakes, a ventral window for the pilot to see below him to engage targets and bomb shackles for a single 500kg (1,100lb) bomb under the fuselage and single 250kg (550lb) ones under each wing. Armament was also altered, with the option of swopping out the two machine guns for two MG151 20mm cannon instead.

Unfortunately, what wasn’t changed was the powerplant, and by this point two 840hp engines were woefully inadequate. Plus, the alterations added quite a bit of weight to the aircraft, and maximum speed was reduced to 298mph (480km/h) unladen.

The aircraft also displayed some unfortunate tendencies for the right-hand engine to overheat, and some stability problems. But despite all this, it was still better than the Ba.88 and so in late 1942 an order for two hundred was placed, though this was later reduced to a total of 110.

Manufacture proceeded, though Italy was in really poor shape by this point of the war, and apparently a total of 75 may have been completed and between 50 and 60 of these actually delivered before Italy signed an armistice with the Allies in September 1943. The delivered aircraft were sent to equip two squadrons in southern Italy who began working up to bring the new type into service.

Unfortunately, the airfield they were based at was also home to a number of other Italian fighter units, and once Operation Husky, the Allied invasion of Sicily began, these were heavily involved in the fighting. And in response to that the USAAF launched a massive air raid with B-24s against the base, the chief effect of which seems to have been the destruction of practically all of the available Ro.57s on the ground.

As a result, the type never actually got to see service, and the subsequent surrender of Italy and switching of sides spelt the complete end of the Ro.57. Which is a bit of a shame as it is an interesting “what-if” aircraft that may have been rather useful had it been accepted for service in 1939 rather than bodged into a new role when it was already past its prime anyway.

Sources/Related:

https://it.wikipedia.org/wiki/IMAM_Ro.57

https://comandosupremo.com/imam-ro-57/

https://web.archive.org/web/20160305090928/http://www.giemmesesto.org/Documentazione/Aerei/ImamRo57.html

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