On July 9, the L-band radar was removed from AV-1 without accomplishing the engineering flight because HS-3 is waiting to use the aircraft. Obviously this was a very disappointing development as the radar was successfully integrated to the aircraft and ready to fly two weeks ago. The Combined Systems Test on June 25 was terminated due to an aircraft engine fault. Dryden and Northrop Grumman teams spent a week troubleshooting the fault condition and determined the probable cause to be the Vehicle Test Computer on the ground and not the aircraft engine or computer. The team was hoping to get a flight off on July 11, but the window of opportunity on the aircraft had expired, and the team was instructed to pack the radar and return home. The next window of opportunity for UAVSAR flights is in October 2013, after the HS-3 mission.