Questions Remain over Cause of Global Hawk Crash

Air Combat Command investigators could not determine a clear cause of the crash of an EQ-4B Global Hawk communications-relay aircraft over Afghanistan last summer, said ACC officials in a release. Several hours into the mission on Aug. 20, 2011, the 9th Reconnaissance Wing controller at Beale AFB, Calif., lost all sensory and control data links with the remotely piloted aircraft, according to the findings of ACC’s accident investigation board. The controller followed proper procedures, but was unable to regain contact with the RPA, states the AIB’s report. Radar tracks showed that the RPA continued flying, until—buffeted by normal atmospheric turbulence—it departed controlled flight, plummeting from 51,000 feet, states the report. The RPA impacted an uninhabited area roughly 105 nautical miles northwest of Kandahar, without additional damage or injury. Loss of the RPA was estimated at $72.8 million. The AIB determined that “a substantially contributing factor” in the mishap was the partial separation of a connector that led to the interruption of electrical power to aileron and spoiler flight-control actuators, rendering the aircraft uncontrollable. (AIB report; caution, large-sized file.)