Despite being cut short by a liquid cooling leak, Boeing’s sixth and final 787 Dreamliner has successfully completed its long-delayed maiden deployment, program sources said. The aircraft, which is the second of two General Electric GEnx-1B-powered 787s, departed Boeing’s Paine Field in Everett, Wash., on Oct. 4 and lasted just over an hour with an aircraft recovery at Boeing Field in Seattle. Program sources say a liquid cooling leak encountered at 39,000 feet prompted the early conclusion to the flight. The 787’s electronics are liquid cooled.