Asiana Crash: Boeing 777 System 'Too Complex'
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, said on Tuesday the pilots were experienced but "over-relied on automated systems that they did not fully understand".
The agency recommended that Boeing "develop and evaluate" changes to the control systems.
Asiana conceded the probable cause of the accident was the crew's failure to check the plane's airspeed, and to abort landing, according to documents released by the NTSB.
But the airline also said the pilots had reason to believe the auto-throttle, which they unintentionally deactivated earlier in the flight, would keep the plane flying at the right speed.
Doug Adler, media relations spokesman for Boeing, told Sky News that the company would carefully review the agency's report.
"Boeing respectfully disagrees with the NTSB's statement that the 777's auto-flight system contributed to this accident, a finding that we do not believe is supported by the evidence," he said.
He noted the system had been used for more than 55m safe landings.
All three of the fatalities in the Asiana crash were Chinese teenagers, one of whom died after she was run over by a fire engine in the confused aftermath.
It was the first fatal accident involving the 777 since its launch in 1995.
It is also the only deadly passenger airline crash in the US in the last five years.