Staff Writer (Updated: 7/6/2016):
The new powerplant was installed into a modified fuselage of the Re.2001. The mainplane structure and tail unit were both retained from the original. Proposed armament would be 2 x 12.7mm heavy machine guns in the upper forward fuselage - synchronized to fire through the spinning propeller blades. 2 x 7.7mm machine guns were fitted to the wing leading edges (one per wing). The aircraft was also envisioned as a fighter-bomber from the start and provision was made for the carrying of up to 1,100lbs of external ordnance under fuselage centerline and underwing areas were also cleared to carry conventional drop ordnance.
Designated as Re.2002, the new aircraft took to the air in prototype form during October of 1940. It was of a clean, contained shape with the large radial engine at front, well shrouded under the cowling. It drove a three-bladed propeller unit that featured a large spinner at center. The cockpit sat aft of the relatively short nose section while ahead of midships. Canopy framing and a raised fuselage spine obstructed some vision out of the pilot's seat. The main wing appendages were also affixed ahead of midships - low mounted along the fuselage sides with curved wingtips. The tail sported a single vertical tail fin with low-set horizontal planes. The undercarriage consisted of two main single-wheeled legs that were retractable under the wings. The tail wheel was externally fixed.
Testing showcased an all-modern aircraft with sound handling and performance qualities comparable to the DB 601-powered Re.2001. Armament was equal to that as seen in the previous product while still capable of engaging and brining down bombers and fighters alike. Performance from the Piaggio engine netted a maximum speed of 330 miles per hour, a range out to 680 miles, and a service ceiling of 34,450 feet - while these numbers were not wholly superior to the Re.2001, it was a viable fighter mount nonetheless.
Italian authorities were slow in their adoption of this Reggiane submission for serial production was not ordered until September of 1941 through an initial batch of 200 under the nickname of "Ariete" ("Ram"). First deliveries then occurred in March of 1942 though delays (primarily centered around the engine) forced operational-level numbers to not be reached until March of 1943 - just months ahead of the Italian September surrender in World War 2.
At about this time, the Germans were sufficiently impressed with the Italian design that they drew up plans for a version outfitted with their BMW radial piston engine of 1,600 horsepower to be used as a fighter-bomber in the ground attack role. Some 300 were envisioned for purchase. However, Reggiane facilities were not able to meet the German demand and none of this type were actually built. Instead, the German Luftwaffe went on to operate the standard Italian Re.2002 form during the remainder of the war - numbering about 60 or so aircraft in their inventory complete with German colors and insignia.
First notable actions involving Re.2002s were over Sicily to counter the Allied landings in the campaign. The aircraft, used in the fighter-bomber role, fared poorly in the fighting - some destroyed while on the ground and others lost in air-to-air combat against more agile, seasoned Allied fighters put forth as air protection for the inbound landing ships. This marked the largest scale use of Regia Aeronautica-managed Re.2002s against the Allies in the war. In September of 1943, Italy formally signed the armistice to end their participation as part of the Axis.
From September 1943 onwards, there were roughly forty Re.2002s in service and these stocked the co-belligerent force created after the surrender of Italy. There also proved its counter, a puppet government (Repubblica Sociale Italiana) with its own fighting air service still in alignment with the Axis. However, it was the German Luftwaffe that continued Re.2002 service for the Axis powers and these were primarily used against French partisan forces into the final year of the war.
Ongoing developmental work by Reggiane engineers eventually produced the Re.2003 - a two-seat, radial-powered, reconnaissance-minded platform based largely on the Re.2002. However, only a single prototype was ever completed with a first-flight on June 29th, 1941. The Reggiane line culminated with the excellent - though limited production - Re.2005 "Sagittario" of 1943. Just forty-eight of this type were produced.