Marshall Aerospace has completed development of an avionics upgrade for the UK Royal Air Force (RAF) fleet of nine Lockheed Tristar tanker-transports. The work was designed to avoid obsolescence problems that now affect these aging aircraft, and to provide compliance with the latest requirements for flying in civil airspace, such as CNS/ATM. The upgrade has taken considerably longer than expected, but the trial installation aircraft has now been returned to the RAF. The Tristar fleet is fully engaged in transporting British troops to and from Afghanistan, as well as in air refueling duties. According to Marshall, “the new navigation displays make it very easy for the crew to maintain situational awareness...despite having to operate in potentially hostile airspace as well as intensive civil air traffic environments.” The Tristars are due to be replaced by Airbus A330MRTTs provided under contract by a private consortium, but a British parliamentary watchdog revealed last year that the new Airbus aircraft will need additional modifications to meet the “minimum theater entry standard” for operating to Afghanistan.