Northrop Grumman has unveiled Gulfstream's new G450 business jet as its candidate to be the platform for the US Army/Navy Aerial Common Sensor (ACS) programme.

Gulfstream formally introduced the G450, formerly dubbed the GIV-NEXT, last week at the National Business Aviation Association's annual meeting in Orlando.

The ACS programme began as the army's next-generation airborne intelligence system, replacing ageing RC-12 Guardrails and RC-7B Airborne Reconnaissance Lows. It has now grown to include most of the navy's cancelled Multimission Maritime Aircraft programme.

The order could range from 52 to 57 aircraft, including 38 for the army and 14 to 19 for the Navy, says Northrop Grumman's ACS executive William Allen. A downselect is due in late February or early March.

The ACS platform, which will be called the RC-20, will carry a sensor suite comprised of an infrared imaging system, signals intelligence and a synthetic aperture radar/ground-moving target indicator.

Northrop Grumman's selection of the G450 offers perhaps the most visible split with its rival Lockheed Martin, which is offering the larger Embraer ERJ-145 regional jet.

Both teams are sparring over claims on affordability, starting with Northrop Grumman's assertion that Lockheed Martin's bid to use a regional jet platform can be "less expensive only if the army accepts a lower level of performance than the operator says they need". Lockheed Martin responds that its analysis of several platforms, including Gulfstream jets, showed the ERJ-145 offered the best value solution.

Gulfstream designed the G450 as a commercial follow-up to the G550, incorporating the latter's PlaneView digital cockpit, 1,839m (6,000 ft) cabin environment and flight control system.

A draft ACS request for proposals was due to be released late last week, offering both teams an early glimpse of any new requirements imposed by the navy.

Source: Flight International