A mechanical failure ultimately brought down an MQ-1B Predator during an Oct. 19, 2015, mission in the Middle East, the Air Force announced Friday. The Predator was flying a mission targeting ISIS as part of Operation Inherent Resolve when it developed a pinhole leak in the elbow radiator of the Predator’s coolant supply line, according to an abbreviated Accident Investigation Board report released Friday. Maintenance personnel reportedly did not detect that the coolant line and another line were too close to each other, which caused rubbing, chafing, and ultimately the leak, the report states. The loss of coolant caused an increase in fuel flow, which degraded performance. The crew, assigned to the 20th Reconnaissance Squadron at Whiteman AFB, Mo., attempted to return the aircraft to base but were unable to maintain safe altitude. The crew ultimately forced a landing in an unpopulated field. The loss of the aircraft is valued at about $4.66 million, according to Air Combat Command.
The Air Force overall reduced its size by 120 aircraft in fiscal year 2021, but kept about the same number of fighter, bomber and attack aircraft, according to data supplied by the service. The F-35 fleet saw the biggest increase while the B-1B bomber fleet saw the largest decline.