On 10 July 2013, an unmanned X-47B drone completed an arrested landing on the flight deck of "George H.W. Bush". The landing marks the first time any unmanned aircraft had completed an arrested landing on board an aircraft carrier operating at sea. The drone completed a second successful arrested landing on "George H.W. Bush", but it was diverted to the Wallops Flight Facility in Virginia after an issue was detected, requiring that a planned third landing to be aborted. One of the drone's three navigational sub-systems failed, which was identified by the other two sub-systems. The anomaly was indicated to the mission operator, who followed test plan procedures to abort the landing. The Navy stated that the aircraft's detection of a problem demonstrated its reliability and ability to operate autonomously. On 15 July 2013, in a fourth attempt, an X-47B drone failed to make a successful flight deck landing on board the vessel due to "technical issues."