Boeing should change flight controls on its 777 airliner following last year's deadly Asiana Airlines crash in San Francisco, say US accident investigators. The National Transportation Safety Board (NTSB) primarily faulted pilot "mismanagement" for the crash, which killed three people and injured 187. The three veteran pilots were found to have committed 20 or 30 errors in the final approach. But the agency's final report also cited the "complexities" of the 777's auto-throttle system and auto-flight director as contributing factors. Boeing, a US manufacturer, said in a statement that it "respectfully disagrees" with the findings. The NTSB's report also faulted insufficient pilot training by the South Korean airline. The wide-bodied jetliner, with 307 people on board, descended too low and too slowly during the landing attempt last July 6. Its tail struck a seawall and tore off. The NTSB's acting chairman, Chris Hart, s...