The Officine Ferroviarie Meridionali, first became involved in the Italian aircraft industry in 1923, beginning manufacturing activities two years later by the licensed construction of Fokker designs. In 1934 Societa Anonima Industrie Aeronautiche Romeo was formed to to takeover the aeronautical activities of the Officine Ferroviarie Meridionali (Aeroplani Romeo). In 1936, the Societa Anonima Industrie Aeronautiche Romeo absorbed all the industrial activities of the Officine Ferroviarie Meridionali and changed its name to Industrie Meccaniche e Aeronautiche Meridionali (IMAM).

In 1934 the company (then the Societa Anonima Industrie Aeronautiche Romeo) had started design and production of a two-seat fighter/reconnaissance biplane under the designation Romeo Ro.37. This was an unequal-span single-bay biplane of mixed wood and metal construction. Its design included fixed tailwheel landing gear (with all three wheels being provided with speed fairings), a braced tail unit incorporating a variable-incidence tailplane and accommodation for two in tandem enclosed cockpits. Power was provided by a 600 hp (448 kW) Fiat A.30RA Vee 12-cylinder inline engine which was prone to overheating in the hot, dry areas of northern and eastern Africa, of which the aircraft principally operated in.

An improved Ro.37bis was developed subsequently, and this introduced an optional radial powerplant comprising either the 560 hp (418 kW) Piaggio P.IX RC.40 9-cylinder air-cooled supercharged radial engine or a 700 hp (522 kW) Piaggio P.XR 9-cylinder air-cooled supercharged radial engine, both rated for maximum output at a lower altitude than the Fiat A.30RA inline engine on the previous model. Both models proved popular for their day, with production of the Ro.37 and Ro.37bis exceeding 160 and 475 respectively, and export orders were received from Afghanistan, Hungary and from countries in Central and South America.

The Ro.37bis first saw combat in Spain, where it was a favourite of the specialist, Cadena or 'Chain' ground-attack units, especially the Spanish Fascist Grupo 4-G-12 and the 120a Squadriglia, XXII Grupo Autonomo "Linci" of the Italian Aviazione Legionaria. Cadena was a tactic that allowed mutual defence against fighter attack and, more importantly, nearly continuous fire against the chosen ground target. The 'chain' was setup so that at least one aircraft was always attacking while the others climbed away or approached in a dive. The tactic kept return fire from the ground to a minimum and let each aircraft cover the tail of the aircraft in front. But it was also very risky, because the aircraft followed a fairly predictable flight path during successive attacks. Some cadena units removed the rear gunners position and operated the aircraft as a single seater, reasoning that the lighter weight would give better performance and maneuverability. The advantages outweighing the loss of a single machine-gun that only gave limited protection.

Ro.37 and Ro.37bis aircraft were involved in the Spanish Civil War from October 1936 and were used extensively by the Regia Aeronautica during Mussolini's invasion of Abyssinia between October 1935 and May 1936 and during the Italian occupation of that country until 1941. Some 275 Ro.37bis aircraft were in service with the Regia Aeronautica when Italy became involved in World War II, and these saw first-line service in the East and North African campaigns and in the Balkans as the standard reconnaissance aircraft of the Squadriglie da Osservazione Aerea. After withdrawal from first-line service they found a variety of uses, but all had been retired before Italy's armistice with the Allies on 8 September 1943.

Variants

Meridionali Ro.37 - The initial production type powered by a 600 hp (448 kW) Fiat A.30RA Vee 12-cylinder inline engine. This engine proved unreliable in the conditions the aircraft operated in. Originally designed to keep drag to a minimum, the faired propeller spinner gave minimal frontal area, but this was offset by the large cooling radiator. As a fighter, it was obsolete from the start, but did serve fairly well in the close support role.

Meridionali Ro.37bis - An aerodynamically improved production version incorporating a 560 hp (418 kW) Piaggio P.IX RC.40 9-cylinder air-cooled supercharged radial engine or a 700 hp (522 kW) Piaggio P.XR 9-cylinder air-cooled supercharged radial engine, both giving better low level performance.

Meridionali Ro.43 - Contemporary with the Ro.37/37bis, the Meridionali Ro.43 was designed and developed as an attractive looking two seat fighter/reconnaissance floatplane for the ship based service. It was an unequal-span single-bay biplane with foldable wings, the upper and lower wing centre-sections being built integrally with the fuselage. Basic structure was of mixed steel-tube and wood, with light alloy and fabric covering, and the landing gear consisted of a large single-step central float of wood, with small stabilising floats mounted beneath each wingtip. Tandem cockpits were provided for the pilot and observer/gunner, and power was provided by a 700 hp (522 kW) Piaggio P.XR 9-cylinder air-cooled supercharged radial engine. A single forward firing 7.7 mm (0.303 in) Breda-SAFAT machine-gun and another 7.7 mm (0.303 in) Breda-SAFAT or Lewis machine-gun on a trainable mount in the rear cockpit made up its armament. Weight empty 3,924 lbs (1780 kg) with a maximum take-off weight of 5,291 lbs (2400). Maximum speed 186 mph (300 km/h) at 8,200 ft (2500 m); service ceiling was 21,665 ft (6600 m); flight endurance 8.5 hours; range 932 miles (1500 km); Span 38 0 3/4 in (11.60 m); length 31 ft 9 3/4 in (9.70 m); height 11 ft 5 3/4 in (3.50 m); wing area 359.10 sq ft (33.36 sq m).

When Italy entered the war in June 1940, the Ro.43 was the Italian navy's standard ship-based catapult-launched floatplane with approximately 105 still being in service out of the 125 aircraft built. About 48 of these were still on strength at the time of the armistice on 8 September 1943. A small number of Ro.43s supplied to neutral Spain were used for air/sea rescue operations throughout World War II.

Meridionali Ro.44 - Some 40 generally similar aircraft were built as Ro.44 single-seat fighter floatplanes, these having the observer's position faired over and his armament and equipment removed, while two forward-firing 7.7 mm (0.303 in) Breda-SAFAT machine-guns replaced the standard single gun of the Ro.43. A number of Ro.43s and Ro.44s were used for shore-based defence of the Aegean islands serving with with 161a Squadriglia Caccia Marina dell-Egeo.   

(Meridionali Ro.37bis)

Type: Two Seat Fighter, Ground Attack, Observation, Liaison & Ambulance

Accommodation/Crew: Pilot & Observer/Gunner

Design: Societa Anonima Industrie Aeronautiche Romeo Design Team

Manufacturer: Societa Anonima Industrie Aeronautiche Romeo. In 1936 the Societa Anonima Industrie Aeronautiche Romeo absorbed the all industrial activities of the Officine Ferroviarie Meridionali and changed its name to Industrie Meccaniche e Aeronautiche Meridionali (IMAM).

Powerplant: One 560 hp (418 kW) Piaggio P.IX RC.40 9-cylinder air-cooled supercharged radial engine. An alternative 700 hp (522 kW) Piaggio P.XR 9-cylinder air-cooled supercharged radial engine was also used.

Performance: (Ro.37) Maximum speed 199 mph (332 km/h) at 13,120 ft (4037 m), landing speed 67 mph (112 km/h), service ceiling of 21,976 ft (6762 m). (Ro.37 bis Piaggio P.IX) Maximum speed 205 mph (330 km/h) at 16,405 ft (5000 m); cruising speed 155 mph (250 km/h); service ceiling 23,620 ft (7200 m).

Range: (Ro.37) 726 miles (1212 km) on internal fuel. (Ro.37bis) 696 miles (1120 km) on internal fuel.

Weight: Empty 3,494 lbs (1585 kg) with a maximum take-off weight of 5,335 lbs (2420 kg).

Dimensions: Span 36 ft 4 1/4 in (11.08 m); length 28 ft 1 in (8.56 m); height 10 ft 4 in (3.15 m); wing area 337.46 sq ft (31.35 sq m).

Armament: Two fixed forward firing 7.7 mm (0.303 in) Breda-SAFAT machine-guns and another 7.7 mm (0.303 in) Breda-SAFAT or Lewis machine-gun on a trainable mount in the rear cockpit plus up to 397 lbs (180 kg) of bombs on underwing racks. Loudout normally consisted of twelve 33 lbs (15 kg) light bombs. On a small number of aircraft two 12.7 mm (0.50 in) Breda-SAFAT heavy machine-guns were used instead of the smaller calibre guns.

Variants: Ro.37, Ro.37bis, Ro.43 (two seat naval floatplane), Ro.44 (single seat naval floatplane).

Equipment/Avionics: None.

History: First flight (Ro.37) 6 November 1934.