The Royal Air Force has declared its third and final Airseeker signals intelligence aircraft fully operational ahead of schedule.

The reconnaissance plane, known more formally as the RC-135W Rivet Joint, will be joined by a ground-based analysis unit.

It is the last of three Airseekers to come into service, with the aircraft intended to replace the Nimrod R1, which was retired in 2011.

Not to be confused with the better-known Nimrod maritime patrol aircraft, the R1 was an electronic intelligence gathering (ELINT) variant.