Provisional design work on a monoplane fighter with retractable landing gears was privately started by a small JAR team in early 1936, to be abandoned at the end of the year due to lack of interest shown by authorities. Corrupt members of the Romanian government had already influenced the military to place a substantial order for the ill-fated PZL P.11. However, the design was secretly warmed up in mid-1937 and eventually lead the prototype of an aircraft comparable to the main fighter designs of those pre-war years.
Designed as a successor to the licence-built P.Z.L. P.24E by a team comprising Ion Grosu, Ion Cosereanu, Gheorghe Zotta and Gheorghe Vallner, the I.A.R.80 single-seat fighter was flown on 20 April 1939 in the hands of Capitan Aviator Constantin Pufi Popeseu, IAR's chief test pilot. The prototype was powered by a 900hp I.A.R.-K 14-II C32 14- cylinder air-cooled radial based on the Gnome-Rhone 14K Mistral-Major and its armament consisted of two wing-mounted 7.92mm FN-Browning guns. The series-production I.A.R.80 appeared in the spring of 1940, and featured a 52cm increase in wing span, a 74cm increase in fuselage length, greater fuel capacity, an aft-sliding cockpit canopy, an armament of four 7.92mm guns and a 930hp I.A.R.-K 14-III C36 engine. The series model also discarded the tailplane bracing struts featured by the prototype.
The first flight of an initial series production dive bomber, the IAR-81, No 81, happened on August 16,1941. The I.A.R.80 achieved operational capability on 14 January 1941 with Flotilla 2 Vinatoare of the Royal Air Forces of Romania (Fortelor Aeriene Regal ale Romania), or FARR. The 50th and last of the initial series (No 175) left the production line in April 1942, and was fitted with an extra pair of guns, this six-gun armament being standardised for subsequent aircraft, which were designated I.A.R.80As, these also having racks for two 50kg bombs and being powered by the 1,025hp I.A.R.-K 14-1000A engine. Ninety I.A.R.80As were followed by 50 I.A.R.80Bs, with an armament of four 7.92mm and two 13.2mm guns, the 21st and subsequent aircraft of this batch having a further increase in wing span of 48cm and provision for underwing drop tanks. Manufacture of the pure fighter version of the basic design was completed with 50 I.A.R.80Cs - originally laid down as I.A.R.81Bs, which see - with 20mm Ikaria cannon replacing the 13.2mm weapons and reintroducing the tailplane bracing struts. A small number of I.A.R.80s remained in Romanian service until late 1949, after which survivors with the lowest hours were rebuilt as I.A.R.80DC tandem-seat dual-control advanced trainers.
The Junkers Jumo 211Da was not the only in-line engine to be experimentally fitted to an IAR-80 airframe. At the end of June 1943, several test flights were performed with an IAR-80 fitted with a Daimler Benz DB 601Aa from a Messerschmitt Bf 109E.
Take-off weight: 2980 kg / 6570 lb
Loaded weight: 2200 kg / 4850 lb
Wingspan: 11.00 m / 36 ft 1 in
Length: 8.97 m/ 29 ft 5 in
Height: 3.52 m / 11 ft 7 in
Wing area: 16.50 sq.m / 177.60 sq ft
Max. speed: 550 km/h / 342 mph