The Ministry of Defence has undertaken no trials with private sector air to air refuelling service providers in the last three years. A commercial service has been used by the RAF in the US, under extant bilateral arrangements with the US Military but this was not a formal trial.
RAF TriStar and VC10 aircraft are designed and certified to strict airworthiness and safety standards. The structural integrity of the aircraft is maintained by adherence to the procedures detailed within military airworthiness regulations. The review of airworthiness and safety of the aircraft is a routine and continual activity. It includes a comprehensive maintenance and repair process that covers routine flight servicing before and after each flight.