Aircraft

The US Army will spend up to $460 million over the next five years to modernise a fleet of nearly 36-year-old signals intelligence (SIGINT) aircraft that only two years ago were expected to retire after 2009.

The army plans to upgrade its 33 Beech RC-12 Guardrail/Common Sensor aircraft to a standard mission system featuring a new version of Northrop's Airborne Signals Intelligence Payload (ASIP).

The army flies RC-12s in three-ship formations to obtain triangulated geolocation of communications and other emitters. The fleet's traditional mission is to locate enemy forces behind the front lines, but its role has adapted to the war zones in Iraq and Afghanistan.

The contract brings Northrop's SIGINT technology on the RC-12 full circle. The Guardrail payloads installed in 1988 formed the basis for the ASIP hardware now flying aboard the US Air Force's Lockheed U-2, and, at a later date, the Northrop RQ-4.

Now, a smaller version of that ASIP system tailored to the army's tactical SIGINT mission will be installed on the RC-12 fleet, says Clark Lewis, Northrop's division programme manager for airborne intelligence surveillance and reconnaissance programmes.

The RC-12's two-chassis payload will more be powerful, but weigh less than the Guardrail system, he adds.

The upgrade will standardise the RC-12 fleet, which now includes four major variants, to a single configuration designated the RC-12N-1.

In 2004, the army planned to replace the RC-12s and de Havilland Canada RC-7s with the Lockheed Aerial Common Sensor. But that contract was terminated in January 2006 after the weight of the mission system outgrew the maximum payload of the Embraer ERJ-145 regional jet platform.