Alenia Aermacchi and ATK have completed a series of trials involving the roll-on/roll-off palletized gun system envisaged for the MC-27J Spartan gunship.

The trials, at Eglin AFB, Florida, saw the aircraft undertake a series of ground and flight trials to prove the installation of the ATK-built GAU-23 30mm cannon in a side-firing configuration from the paratroop door in the rear cabin of the aircraft.

In a press release issued on the eve of the Paris air show, the two companies said that live-fire tests and timed demonstrations to transform the aircraft from a cargo configuration into a weaponized configuration had “exceeded all test objectives.” According to the companies, the tests were designed and certified by the U.S. Air Force and were “deemed successful by Air Force Special Operations Command.”

The two companies launched their plan to develop a multimission version of the C-27J airlifter at the 2012 Farnborough Airshow. The plan is to use a roll-on/roll-off set of pallets including the gun, mission consoles, and launch modules for precision-guided weapons.

The palletized gun is on display at the Paris Air Show fitted inside a black-painted C-27J.

ATK is working on the palletized system for the aircraft. The two companies are offering up to four levels of configuration, including a basic and enhanced command and control system and ISR capability and then a basic and enhanced gunship kit.

In the enhanced gunship configuration, the aircraft is fitted with two electro-optical pods fitted front and midfuselage, and a mission and fire control system fitted in the cabin operated by two weapons systems operators.

The primary weapon is the ATK-built 30mm cannon, which sits in the rear fuselage on a standard 463L pallet. The gun barrel is fitted through a fairing on the port-side rear paratroop door. The weapon, which is also used on the Lockheed AC-130W Stinger II, sits on a stabilized mount and can be traversed and aimed using the onboard sensors.

ATK envisages that the guided munitions, which could include the Raytheon AGM-175 Griffin or the Northrop Grumman GBU-44 Viper Strike, will be soft fired either by opening the ramp and ejecting the weapons out the back of the aircraft or potentially dropped through a series of launch tubes cut out of the cargo-loading ramp. The latter method would allow the aircraft to remain pressurized.

The companies say they are now preparing for the next round of testing, which will advance the technology readiness level of the systems onboard.

The two companies believe there may be a market for as many as 50 ISR and gunship-equipped aircraft over the next 20 years.