Accordingly, Aermacchi designed it as a single type of aircraft that could readily perform both elementary and advanced training right through to a near combat-ready standard.

After it was proposed during the 1950s, the Italian Air Force (AMI) quickly became interested in the MB-326, and an initial contract to produce three prototypes was issued following a competition.

Over time, the MB-326 found its primary role as a lead-in trainer to prepare pilots for transition to very high performance fighter aircraft.

While the majority of operators were military, some civil organisations also flew the type; Italy's national flag carrier Alitalia conducted pilot training using a handful of MB-326s.

Recognising the potential to better fulfil this role, several different companies independently chose to commence the development of purpose-built aircraft to serve as trainers; these included the French Fouga Magister, the American Cessna T-37 Tweet, the British Jet Provost, and the Czechoslovakian Aero L-29.

In the aftermath of the devastating Second World War, Italy spent a number of years recuperating and reestablishing its economy; as such, the nation found itself unable to prioritise the necessary financing for the independent development of high-end combat aircraft that would be competitive with the upcoming generation of supersonic interceptors or bombers; accordingly, Italian aviation company Aermacchi elected to instead focus its resources and development efforts upon the production of a line of light fighters and trainer aircraft.

The service was considering options for the potential replacement of its existing trainer fleet, thus, upon the commissioning of a competition to select a suitable successor, the MB-326 was an obvious early entrant.

Amongst these changes was the elimination of the negative dihedral angle previously present on the horizontal tail surfaces and the substitution of a pair of wing-based airbrakes into one located at a ventral position.

During 1956, the AMI gave its official approval of the project and issued a request for the production of a pair of prototypes (later designated as MM.571 and MM.572) as well as a single airframe for static tests.

These prototypes were not intended to include several features, such as the ability to equip and deploy armaments or refinements such as cabin pressurization, however, Bazzocchi chose to introduce them regardless.

However, the G.80 had several disadvantages, including being heavier, considerably larger and more expensive than its rival; as such, it ultimately lost the trainer contest and remained without a market.

[3] During 1960, a larger follow-on order for 100 aircraft was received by Macchi; this sizable commitment was viewed as being a major step towards establishing the company's supremacy in jet trainer market.

[3] As originally developed, the MB-326 functioned as a refined but simple aircraft capable of covering the considerably wide range of performance characteristics required to cover both ab initio training and advanced instruction alike; other major characteristics of the type included the capacity to deliver a high rate of utilization in conjunction with minimised servicing and maintenance requirements.

In addition to being relatively easy to fly, a high degree of safety was also intentionally built into it, including adoption of new Martin-Baker-built ejection seats.

[3] The engine possessed multiple favourable attributes, including its general simplicity and robustness, relatively low revolutions per minute (RPM) and turbine entry temperature (TET), rapid acceleration, ease of installation, and its somewhat forgiving nature to mishandling in the air by students.

The Viper was produced under licence by Italian aviation company Piaggio following an agreement established with its original manufacturer, the British engine firm Bristol Siddeley, during 1959.

Accordingly, the MB-326 was readily capable of performing relatively slow speed take-off and landing while retaining an excellent rate of climb.

It was covered by a bubble canopy for excellent external visibility; it featured a windscreen anti-icing system powered by the engine compressor using bleed air.

The ability to fly at higher altitudes was favourable for multiple purposes, including during the execution of aerobatic and navigational training, as well as improving fuel efficiency for long-distance flights.

Another pilot Riccardo Peracchi, who was employed by for AMI, frequently demonstrated the manoeuvrability and controllability of the aircraft at airshows for a number of years.

While Peracchi displayed the MB-326's agility, Ralli concentrated on exploring its cutting-edge performance; meanwhile, early customers of the aircraft were typically reporting their satisfaction with the type to Macchi.

[4] The first production MB-326s, following a relatively protracted development cycle, were first delivered to the Lecce-Galatina school of the AMI's 214° Group, these were temporarily fielded at Brindisi, Apulia.

The "C" version was envisioned as being provisioned with a nose-mounted North American Search And Ranging Radar (NASARR) unit and other electronic equipment in order to be used for the training of AMI F-104 pilots,[7] however, this variant only appeared as a mock-up.

[15] The Impala Mk II, locally manufactured and equipped with French armament, was also advanced with a South African ECM suite.

[19] These cannons were the real bonus for the Impala Mk II, helping to give a superior performance compared to earlier two-seat versions.

[15] A number of MB-326 aircraft, together with the more modern MB-339, formed the equipment of the Argentine Navy's 1 Escuadrilla de Ataque in 1982, when Argentina invaded the Falkland Islands.

[23] In stark contrast to the competing Fiat G.91, which was often considered to be not very convincing as a light fighter, the MB-326 was quick to achieve several export successes in this capacity.

However, the MB-326 did achieve a visible measure of success amongst many Third World countries, leading to the MB-326 seeing considerable use as a front-line combat aircraft in a number of regional conflicts.

The measures to save costs led the MB-326 to be frequently substituted for by propeller-driven models, however, the Macchi was often flexible enough to act as a medium trainer and light attack aircraft.

Data from Jane's All The World's Aircraft 1969–70[65]General characteristics Performance Armament Avionics SFOM fixed gunsight or Ferranti LFS 5/102A gyro-gunsight