The UK has signed a deal worth $1bn with the US Government for three RC-135W Rivet Joint signals intelligence aircraft for the Royal Air Force (RAF), a Ministry of Defence spokeswoman has confirmed.

Defense News quoted the spokeswoman as saying, “The MoU establishes a cooperative agreement through to 2025 for the support of the UK’s Rivet Joint system.”

The deal, part of a sales agreement sealed last year, enables the UK to access spares to support its in-service equipment and deep maintenance of the aircraft fleet that includes capability updates every four years.

L-3 Communications is responsible for modifying the KC-135R aircraft to the Rivet Joint configuration.

The delivery of the first airframe to the RAF is scheduled for April 2014, but is expected to take place in December 2013.

The co-manning of USAF Rivet Joints is to partially bridge the gap in capabilities between the decommissioned Nimrod R1s and the introduction of the RAF’s new aircraft.