UK Rivet Joint flight restores key RAF capability - 5/29/2014 - Flight Global
Personnel from the UK Royal Air Force’s 51 Sqn have begun performing training flights using the unit’s first RC-135W Rivet Joint signals intelligence aircraft, following the receipt of initial release to service approval....
“The RC-135W has been cleared by the RAF’s release to service authority, to fly to an initial release to service [and] to a flight envelope that meets the current operational requirement,” the Ministry of Defence says. “Ongoing work will progressively refine this release as additional information becomes available and further analysis is conducted.”