The Fiat Aeritalia G.91 was an Italian Cold War-era, single-seat, jet-powered fighter design that saw an extended period of service with only a handful of operators throughout Europe. She was once envisioned to stock the inventories of multiple European allies in the NATO consortium but circumstances dictated that she just see service primarily with the air forces of Italy and West Germany. Portugal became another , albeit later (and perhaps its most active), operator of the system and showcased her strengths (and weaknesses) through several conflicts centering around her colonial interests. Approximately 756 to 770 examples (sources vary) were ultimately manufactured and delivered, these comprised of two distinct airframes and included dedicated forms, each wielding a healthy blend of firepower and performance. Her service spanned an impressive thirty-seven years, making her one of the more successful - though lesser known - Cold War jets. The G.91 was known by the nickname of "Gina".
The G.91 was birthed out of a 1953 NATO specification calling for a light strike fighter aircraft capable of "rough field" operations while still being able to maintain an operating speed reaching Mach 0.95 - of course this platform would have to come at a reasonable price as well. The request was sent out ultimately involved any European aviation firms as well as Northrop in the United States. The intent was for the NATO coalition to be able to field a battlefield component requiring little beyond what might be made available in forward operating bases during the stresses of wartime. The threat had always been of a mass invasion of Eastern Europe by Soviet air and land armies and NATO members would need the proper tools to react and - ultimately - repel such an attack. This approach was in direct contrast to the high-end technological marvels (themselves coming with higher purchase and operating costs) common to this period of the Cold War era.
Perhaps inspired by the successful North American F-86 of Korean War fame, Italian aircraft engineer Giuseppe Gabrielli of Fiat Aviazone designed a similar-looking compact, single-seat/single-engine fighter platform with highly swept wings to be produced at relatively acceptable costs, require little field maintenance (or specialized ground equipment) and be manufactured with very basic avionics and weapons delivery suites. The selected powerplant of choice for the program became the British Bristol Siddeley Orpheus turbojet engine. The Fiat Aviazone product took on the designation of "G.91" with the "G" signifying Gabrielli's direct involvement in the design. The new light strike fighter carried with it the potential to be fielded by a wide variety of European nations and, thusly, a lucrative production contract awaited the victor with the best offering.
Along with Fiat and Northrop's entry, Dassault, Sud-Est, Aerfer and Breguet each submitted a potential design. In all, some ten aircraft possibilities were entertained with assessment beginning on March 18th, 1953. Fiat earned a contract to produce three prototypes and up to 27 pre-production aircraft.
First flight of the G.91 was achieved on August 9th, 1956 but was lost to an accident causing the French government to pursue their own design solution with their Dassault Etendard. Likewise, the British looked to further in-house development of their excellent Hawker Hunter in a like-minded role. The Italian government continued interest in the G.91 and ordered their pre-production aircraft for operational evaluation.
Following the loss of the first prototype, the G.91 was revised for the better. Her vertical tail fin had her surface area expanded, creating a larger tail fin, and a ventral strake was added at the base of the empennage. The canopy was raised some 2-inches providing for better vision out of the cockpit while addressing airflow. The revised G.91 was successfully test flown in July of 1957 but was interestingly not for evaluation. Regardless, the new design proved wholly sound, her handling noted as being quite easy to her pilots, and performance from the Bristol Siddeley Orpheus engine was good. All of the submitted designs were evaluated in 1957 with the G.91 coming out on top. Incidentally, the Northrop submission - an N-156 - would go on to become the F-5 Freedom Fighter/Tiger II series of light multi-role fighters.
Like most early jet-powered engine systems, the G.91 was fully capable of exceeding the speed of sound but this was only possible when in a dive. The second prototype was followed by a third and a fourth model which were submitted for evaluation. Despite all of the work and promising reports surrounding the G.91, interest ultimately waned and the mount was only selected into service by the Italian and West German air forces. Other once-interested parties elected to pursue their own internal ventures. The pre-production G.91s ordered by the Italian government, upon having served their purpose in the short-term, went on to live an extended and healthy life with the "Frecce Tricolori" Italian acrobatic team under the designation of "G.91 PAN". One hundred seventy-four and one-hundred forty-four G.91s were produced and delivered to Italy and West Germany respectively.
Italy's first G.91 was delivered in August of 1958 culminating in the first operational G.91 unit. The second group followed in 1961. Once in service with the Regia Aeronautica, the G.91 performed as advertised, become the mount of choice for many generations of up-and-coming Italian military aviators. The type would serve for a lengthy period, often times on stand-by to head-off a Soviet assault, before finally being removed from service as late as 1995.
West German G.91s
Further production was handled in Germany by Flugzeug-Union Sud resulting in 294 more Luftwaffe G.91 aircraft. It is notable that this German fighter production was the first of its kind since the end of World War 2 when Germany's war-making capabilities were severely restricted (yet again). Orders included a mix of strike variants, reconnaissance versions and trainer models. However, once in operational service with the Luftwaffe, the G.91 really failed to deliver in terms of the performance the Luftwaffe sought for its light fighter squadrons. The changes instituted from the second prototype onwards and an additional pair of underwing weapons pylons along with its cannon armament added considerable weight to the German G.91s. All this worked to deteriorating performance somewhat. As a result, the West German government curtailed its expected orders. Despite the drawbacks, the German G.91 proved to be an affordable solution and, in some ways, was a better combat aircraft than her Italian counterpart. An initial batch of a dozen Fiat-Aeritalias were the first to arrive for Luftwaffe service. The indigenously-produced West German models began deliveries after 1960.
Portugal received, by way of outright purchase, used G.91s from West Germany in 1965. Portugal had grown increasingly entangled in colonial wars within her African interests resulting in the aptly-named Portuguese Colonial War (1961-1974). Her colonies were growing evermore nationalistic and steering towards independence while being backed by powerful allies in the United States, the Soviet Union and China. To Portugal's name, limited support came from Rhodesia and South Africa. The nation was in need of a semi-modern platform that it could use in the Close Air Support (CAS) role, these elements charged with engaging enemy ground forces within direct contact with friendly ground forces.
Portugal originally intended to purchased about 100 used North American F-86 Sabres Mk 6s - these being Canadian-manufactured versions of the fine American fighter - then in service with the West German Air Force. Instead, West Germany offered up her stable of used G.91s to which Portugal purchased in a lot of 40 examples. The Portuguese G.91 arrived ready for duty in Guinea in 1966. Further deployment saw the G.91 in action over the skies of Mozambique. The only true threat for the small fighter began in 1973 as the Soviet Union began delivery of the SA-7 "Grail" - a portable, shoulder-launched anti-aircraft missile produced in some number and made available to communist friendly satellite states and allies.
Things changed for Portugal politically by 1974. A UN arms embargo against the current government a year earlier made purchase of such weapon systems nearly impossible and a new government party (and political mindset) ultimately unseated the current power holders, resulting in the independence movement of the colonial entities to come to fruition without further bloodshed. All G.91s were recalled to mainland Portugal by January of 1975. In 1976, fourteen more retired West German G.91s were purchased along with 7 two-seat trainers. Nearly 100 G.91s eventually found their way into the Portuguese inventory. By 1993, all G.91s were officially retired in favor of more modern systems, bringing a Portuguese end to the sound legacy of the Italian fighter.
Fiat G.91 Walk-Around
Design of the G.91 was reminiscent of the North American F-86 Sabre, more specifically the late model F-86 Sabre Dog "snout" nose interceptors. The cockpit was fitted directly behind a the short nose assembly which, itself, protruded ahead of the low-mounted intake opening. The intake aspirated a single Fiat/Bristol Siddeley Orpheus 803 series turbojets, each capable of up to 5,000lbs of thrust. The engine component took up most of the lower fuselage space with the turbojet running a good distance length-wise of the internal fuselage. The fuselage was somewhat oval in shape when viewed in the forward profile but sported a slab underside. Wings were swept back at extreme angles both along the leading and trailing edges and mounted low along the fuselage sides. Each wing was afforded a single hardpoint on the Italian production models while the German variant was fitted with two such pylons. The inner-most positions on these machines were cleared to handle the heavier ordnance loads and external fuel tanks. Identifiable to the series was its single boundary layer fences running partially across the top of each wing, outboard of the standard underwing pylons. The empennage was conventional and dominated by a single vertical tail fin making up the rudder component and two high-set horizontal planes making up the stabilizers (the latter set along the fuselage sides. All tail surfaces were equally swept, following in line with that of the main wing assemblies. The undercarriage was a conventional tricycle arrangement featuring two main single-wheeled landing gear legs and a single-wheeled nose landing gear.
The pilot sat under a curved two-piece glass canopy with excellent forward and side views. His "six" was partially obstructed by way of a small raised spine contouring into the upper portion of the fuselage. The cockpit was well lit and organized, featuring a forward instrument panel containing the basic flight gauges and system monitors. Control was via a conventional flight stick positioned between the pilots knees. An adjustable gunsight dominated the top of the instrument panel, straddled on either side by the vertical frames of the forward canopy assembly.
Armament varied slightly per operator. The standard Italian design fitted 4 x 12.7mm (.50 caliber) Browning M2 air-cooled heavy machine guns as standard. The German Luftwaffe replaced this battery with 2 x 30mm DEFA cannons instead (at the cost of additional weight and less ammunition). The four underwing hardpoints (two in the Italian production versions) could sustain up to 4,000llbs of ordnance or less depending on the production model type. Munitions could include Matra SNEB 19-shot 68mm rocket pods, Hispano SURA R80 80mm rockets, gun pods and most types of conventional drop ordnance. Auxiliary fuel tanks could be fitted to the base underwing weapon pylons for increased range or ferrying.
Performance from the single engine arrangement (in the G.91R model series) yielded a top speed of 668 miles per hour, a range of 715 miles and a service ceiling equal to 43,000 feet with a 6,000 foot-per-minute rate-of-climb.
The G.91 was produced in a few major variants during her tenure and centered mainly around the base strike, reconnaissance and trainer model categories. The G.91 designation was used to signify the prototype and pre-production airframes. The G.91R/1 was a light attack/reconnaissance model with three camera systems fitted to the nose. The G.91R/1A designation was used to signify these same models but with revised instrumentation. The G.91R/1B featured a strengthened internal airframe. The G.91R/3 was a dedicated ground strike and reconnaissance model for use exclusively by the German Luftwaffe. These were fitted with 2 x 30mm cannons replacing the original 4 x 12.7mm machine guns. The similar G.91R/4 was armed with the 4 x machine gun battery and powered by the Rolls-Royce brand powerplant. G.91PAN was used to designate the Frecce Tricolori acrobatic team, these made up of the pre-production G.91 airframes no longer needed. The G.91 appeared in two trainer forms for the Italian Air Force and the German Luftwaffe as the G.91T/1 and the G.91T/3 respectively. The Italian G.91T/1 were conversion models of the production G.91R/1. Trainers were, of course, differentiated by their tandem two-seat layout resulting in slightly lengthened fuselage. Conversely, all R-series aircraft were single-seaters.
The G.91Y existed as aircraft produced under the Aeritalia banner and initially observed as a further development of the G.91R reconnaissance series. These aircraft evolved into essentially "all-new" aircraft fitting 2 x General Electric J85 turbojet engines over the original single Orpheus powerplant. The new arrangement improved both operational range and payload capabilities of the base G.91 as well as improved key performance figures (top speed was now 690 miles per hour). First flight was achieved on December 12th, 1966. A pair of 30mm DEFA cannons was standard over the original 4 x 12.7mm machine gun set up. Sixty-seven G.91Ys served solely with the Aeronautica Militare with deliveries spanning from 1971 to 1975.
Beyond Italy, Germany and Portugal, other limited flyers of the G.91 included the Hellenic Air Force of Greece, the United States Navy and the United States Air Force. All evaluated the G.91 in limited numbers (4, 3 and 4 respectively) but none were ordered for series production and delivery. Austria, Norway and Switzerland all considered purchase of the G.91.