The Fiat BR.20 Cicogna () was a low-wing twin-engine medium bomber that was developed and manufactured by Italian aircraft company Fiat Aviazione. It holds the distinction of being the first all-metal Italian bomber to enter service; it was regarded as one of the most modern medium bombers in the world.
The origins of the BR.20 were in a request issued by the Regia Aeronautica (Italian Royal Air Force) during 1934 for a new medium bomber capable of high speeds, long range, and satisfactory payload, reliability, and flight characteristics compared to contemporaries. Among the companies that chose to respond was Fiat, which completed its design for the competition during 1935. On 10 February 1936, the first prototype (serial number M.M.274) conducted its maiden flight. Flight testing proceeded at a rapid pace; during September 1936, initial deliveries of the type commenced to the Regia Aeronautica.
During summer 1937, the BR.20 received its baptism of fire when a number were operated by the Aviazione Legionaria during the Spanish Civil War: the BR.20 came to form the backbone of Nationalist bombing operations, along with the German Heinkel He 111 bomber. It was also produced under licence in Japan, and the type saw combat during the late 1930s with the Imperial Japanese Army Air Service during the Second Sino-Japanese War. During 1939, a modified long-range BR.20 version (designated BR.20L) named Santo Francesco under the command of Maner Lualdi performed a highly publicised non-stop flight from Rome to Addis Ababa, Ethiopia.
Upon the entry of Italy into the Second World War during mid-1940, the BR.20 served as the standard medium bomber of the Regia Aeronautica, by that point, the type was already approaching obsolescence. The type saw front line use during the Battle of France and the Battle of Britain. By 1942, the BR.20 was mostly used for maritime patrol and operational training for bomber crews. It was produced from the mid-1930s until the end of the Second World War. More than 500 BR.20s were built before the end of the conflict.
Development Background During 1934, the Regia Aeronautica issued a request to Italian aviation manufacturers, asking them to submit their proposals for the production of a new medium bomber. The specifications called for it to be capable of speeds of at and at , a range and bombload. Various companies chose to respond, including Piaggio, Macchi, Breda, Caproni and Fiat; the majority of these offered aircraft that would have exceeded the speed requirements, but not the sought range; additionally, not all designs exhibited satisfactory flight characteristics or reliability levels.
Fiat's design team, headed by aeronautical engineer Celestino Rosatelli, set about designing a bomber that would be capable of relatively high speeds while using a simple and rugged construction and maintaining a low weight. According to aviation author G. Apostolo, the design "represented a departure from the line of aircraft previous designed by Ing. Celestino Rosatelli" and that it made use of elements of Fiat's earlier prototype civil airliner, the APR.2. The design, which later named the BR.20, was modern and competitive with other Italian bomber aircraft. The BR.20 Cicogna was amongst those proposals to be accepted by the Regia Aeronautica, together with the trimotor Savoia-Marchetti SM.79 and Cant Z.1007, thus gaining the prefix BR, (for "Bombardiere Rosatelli").
Into flight The BR.20 moved swiftly through its design and development phases, the design being finalized during 1935. On 10 February 1936, the first prototype (serial number M.M.274) performed its maiden flight from Turin, flown by Fiat test pilot Rolandi. Following the first flight, it was transferred to Guidonia Montecelio within the Metropolitan City of Rome for an accelerated evaluation programme.
Production orders for the type were quickly placed by the Regia Aeronautica; during September 1936, initial deliveries of the BR.20 commenced to 13° Stormo Bombardamento Terrestre of the Regia Aeronautica. Testing of the aircraft continued even after this point; during June 1937, three aircraft were dispatched to a pair of bases in Benghazi and Tripoli, Libya, to conduct test flights under tropical conditions. The initial production bombers differed from the earlier prototype in various ways, particular in the finer details of the nose, fuselage and tail.
Cicogna vs. Sparviero Despite the BR.20 being the winner of the 1934 bomber competition, the Savoia Marchetti SM.79 Sparviero, a non-competitor which was developed at practically the same time, gained a reputation that overshadowed the BR.20 Cicogna, partly because of its performance during several air races. The performance differences between the two aircraft were minimal: both were rated at about with maximum and typical payloads of and respectively for a range of . Both bombers also possessed an assortment of three to four machine guns as defensive weapons, but almost completely lacked protective armour.
The reasons for the Sparvieros success lay in its flying characteristics. The Sparviero was a more difficult aircraft to fly with a heavier wing loading, but its three engines provided more power than the twin-engine arrangement of the BR.20. The Sparviero, weighing around the same, had a reserve of power and was capable of performing acrobatic manoeuvres, even rolls. Its engines were more reliable than those of the BR.20 and had enough power to return to base even with one shut down. The Sparvieros superior agility enabled it to perform as a torpedo-bomber, while the Cicogna was never considered for that role. Over 1,200 Sparvieros were constructed, at least twice as many as the Cicogna.
Further development Upon its introduction, the BR.20 was a modern aircraft and benefited from a good design; the bomber quickly became obsolete in the rapid advances made in aeronautics. The scarcity of improved versions of the aircraft condemned the BR.20 to be only viable in the role of a second-line machine, being underpowered and lacking in defensive firepower by the outbreak of the Second World War. By the time Italy had entered the war, a new variant of the bomber, designated as the BR.20M, had been produced and put in service. The improved BR.20M featured a different nose with additional glazed sections for the bombardier, along with a slightly longer fuselage. The weight increased because a part of the fabric was substituted with metal, improving the resistance to flutter and vibration from the engines while reducing speed from to .
The final production variant was the BR.20bis, which was a redesign of the aircraft. It featured a fully glazed nose, a retractable tail wheel, more streamlined fuselage and pointed fins, although the principal change involved was increased engine power from a pair of Fiat A.82 RC 42 radial engines, along with an improved and heavier armament. The nose held a simple machine gun position rather than the turret used on earlier aircraft and two waist blisters were fitted over the wing trailing edge while the dorsal turret was a Breda Type V instead of the earlier Caproni Lanciani type. The BR.20bis was considered to be an improvement, particularly in its aerodynamics. Plans for production was delayed, in part due to technical problems that took time to resolve, and a decision by the Regia Aeronautica to place large orders for the competing CRDA CANT Z.1018 instead. Originally, 98 aircraft were ordered, but only 15 BR.20bis were built from March to July 1943, with severe Allied bombing of Fiat's Turin factory preventing further production. There is no evidence that any of these were used on operations.
Various experimental versions were developed. These included the BR.20C, a gunship with a cannon in the nose, while another aircraft was modified with a tricycle undercarriage. Yet another aircraft was modified to guide radio-commanded unmanned aircraft filled with explosives, but it was never used in combat. Including those bombers which had been sold to Japan, at least 233 standard BR.20s were manufactured along with an additional 264–279 BR.20Ms that were constructed from February 1940.
Design Overview
The Fiat BR.20 was a twin-engine low-wing cantilever monoplane medium bomber. The primary mission of the aircraft was to perform medium-range bombing. The BR.20 was provided with a large number of design features that were very advanced for its time: the aircraft was capable of a maximum speed in excess of and a relatively high cruise speed of , being as fast as the better of its international competitors, such as the Tupolev SB light bomber. In spite of this, the range and payload of the bomber were also comparatively favourable for the era.
The engines were a pair of Fiat A.80 RC 41 radial engines, rated at 1,000 cv at , which drove three-bladed Fiat-Hamilton metal variable-pitch propellers. A group of six self-sealing fuel tanks, housed within the center fuselage and the inner section of the wings held a combined of fuel, along with a pair of oil tanks which held . When fully loaded with a payload, the bomber would have flight endurance time of 5½ hours when flown at and an altitude of . The takeoff and landing distances were and respectively, while the theoretical ceiling was .
Armament In terms of its self-defence capability, the BR.20 was fitted with a Breda model H nose turret, armed with a single 7.7 mm (.303 in) Breda-SAFAT machine gun. It was initially fitted with a Breda DR dorsal turret which was furnished with either one or two 7.7 mm (.303 in) machine guns; this turret was unusual because it was semi-retractable: the gunner's view was from a small cupola, and in case of danger, the turret would then be extended. This was later replaced by a Fiat-built M.I turret armed with a 12.7 mm (.5 in) Breda machine gun, then by a Caproni-Lanciani Delta turret mounting a 12.7 mm (.5 in) Scotti machine gun (although this proved to be unreliable). It was finally replaced by a more streamlined Breda R turret, armed with a 12.7 mm (.5 in) Breda; this was a superior system that did not need any retraction mechanism because of the lower drag. In addition to this, the bomber was fitted with a 7.7 mm (.303 in) machine gun within a ventral clamshell hatch that could be opened when required. The original defensive armament weighed 220 kg (480 lb).
The offensive payload of the BR.20 was carried entirely in the bomb bay, which was isolated from the rest of the aircraft by an aluminium sheet. It could contain various armaments in the following possible combinations: 2 × 800 kg (1,760 lb) bombs as maximum load, 2 × 500 kg (1,100 lb), 4 × 250 kg (550 lb), 4 × 160 kg (350 lb), 12 × 100 kg (220 lb), 12 × 50 kg (110 lb), 12 × 20 kg (40 lb), or 12 × 15 kg (30 lb) bombs. Combinations of different types were also possible, including 1 × 800 kg (1,760 lb) and 6 × 100 kg (220 lb), 1 × 800 kg (1,760 lb) and 6 × 15 or 20 kg (30 or 40 lb), or 2 × 250 kg (550 lb) and 6 × 50 or 100 kg (110 or 220 lb) bombs. The BR.20 could also carry four dispensers, armed with up to 720 × 1 or 2 kg (2 or 4 lb) HE or incendiary bomblets. All the bombs were loaded and released horizontally, improving the accuracy of the launch. There was no torpedo armament adopted during its service life.
Structure