Aircraft

Northrop Grumman will supply a major piece of the signals intelligence system that will fly aboard the US Army's long-awaited Aerial Common Sensor (ACS) fleet.

Any competitor that wins the pending ACS contract will be directed to use a variant of Northrop's airborne signals intelligence payload (ASIP), a system used for intercepting electronic signals and tracking them back to their source.

Northrop developed ASIP in the past decade to become the new primary signals sensor for the US Air Force Lockheed U-2 surveillance aircraft. A scaled-down version will also be integrated on the Northrop RQ-4 Global Hawk unmanned air vehicle.

The army became involved in ASIP technology last September, awarding Northrop a $460 million contract to convert the payload for its ageing fleet of 33 Beech RC-12 Guardrail/Common Sensor aircraft. Northrop flew a prototype system for the RC-12 for the first time in February.

The RC-12s are being upgraded to keep the fleet viable until the future ACS system is ready. The original ACS replacement programme collapsed in January 2006 after the Lockheed Martin/Embraer team realised the sensor system greatly outweighed the payload limit of the ERJ-145.

The army intends to issue a request for proposals for the new ACS programme in the third quarter of this year. During a recent industry day, army officials clarified the ACS acquisition strategy, says Mike O'Brien, Northrop's director of intelligence, surveillance and reconnaissance.

Northrop's adapted ASIP system will be the only piece of the on-board mission system that is being pre-determined. Specifically, the ACS version of ASIP will satisfy the army's requirement for a communications intelligence system. Payloads for all other SIGINT requirements will be subject to competition.

Northrop is also one of several potential competitors vying for the systems integrator role. O'Brien declines to identify the company's aircraft selection.

In the first competition, Northrop lost with a bid based on the Gulfstream G450. The larger G550 is understood to be a competitor for the revived ACS contract. Northrop also has recently partnered Bombardier to adapt the Global Express XRS business jet as a communications gateway.

Boeing, Lockheed and Raytheon are also considered likely competitors for the ACS contract.