Loss of engine coolant caused the crash of an MQ-1 Predator remotely piloted aircraft just outside the perimeter fence of Kandahar Airfield, Afghanistan, on January 30, announced Air Combat Command officials. The aircraft’s coolant pump supply line failed, releasing coolant, and leading to the engine’s temperature increasing “excessively,” according to ACC’s May 30 release citing the findings of the abbreviated accident investigation board report. The temperature increase reduced power output and prevented sustained flight, causing the airplane to fall into an uncontrolled descent, states the release. Remote operators regained control long enough to guide the Predator to a forced landing, it notes. The aircraft was destroyed on impact, along with one Hellfire air-to-ground missile. The damage amounted to an estimated $4.5 million, according to ACC. Among the contributing factors, investigators found that a maintainer failed to detect damage on the coolant supply line during a 60-hour engine inspection four days prior to the mishap. (AIB report; caution, large-sized file.)
Defense experts say the drone threat represents only part of a larger, looming problem: U.S. air bases in the Pacific are increasingly vulnerable to air attacks.