Northrop Grumman has designed, developed, integrated and fielded a Mode S upgrade to the Identification Friend or Foe (IFF) interrogator for the Sentry E-3D Airborne Warning and Control System (AWACS) fleet based at Royal Air Force Waddington.

The IFF interrogator is a sophisticated airborne defence system that provides a long-range, rapid early warning and detection capability, allowing discrimination between friendly and hostile aircraft. The Mode S system enables the aircraft to be used in controlled airspace.

The work was performed at Royal Air Force Waddington under Northrop Grumman's existing Sentry E-3D Whole Life Support Programme (WLSP), and is the most complex of a series of modifications the company has carried out to date for the Sentry aircraft fleet.

"This innovative system upgrade has eliminated the need for complete mission computer replacement, thereby providing the Ministry of Defence with a comprehensive, affordable solution to the Civil Aviation Authority's upgrade requirement," said John Parker, director, weapon system sustainment and modernisation, Northrop Grumman Technical Services.

"The new, open architecture system also provides a foundation for future incremental hardware and software upgrades to support sustainment of the Sentry E-3D."

"Northrop Grumman partnered with the Sentry Project Team to develop and integrate this complex, critical capability," said Group Capt. Adam Northcote-Wright, Air ISTAR delivery manager, Defence Equipment and Support. "This combined effort delivered a cost effective Mode S solution that has achieved full operational capability across the U.K. Sentry E-3D fleet."

Northrop Grumman delivers the WLSP for the Sentry E-3D AWACS fleet and is on contract until 2025. The company is the design organisation, providing long term U.K.-based technical support to the programme.

Working in partnership with the Air ISTAR Programme Team, Northrop Grumman provides a wide range of through-life services needed to support the Sentry E-3D AWACS aircraft. Northrop Grumman also provides the radar and in-service support for the radar. Members of Northrop Grumman's Joint Sentry Support Team include BAE Systems and AAR.