There are no signs of failure of the autopilot or other key automatic flight equipment on the Asiana plane that crashed in San Francisco last week, the head of National Transportation Safety Board said on Thursday.
"There is no anomalous behavior of the autopilot, of the flight director, and of the auto-throttles, based on the FDR (flight data recorder) data reviewed to date," NTSB Chairwoman Deborah Hersman told a news conference, referring to the flight data recorder from the Boeing 777.
The plane, carrying 291 passengers and 16 crew from Seoul to San Francisco, hit a seawall in front of the runway on Saturday, killing two passengers and injuring 180 others.
The tail section of an Asiana Airlines plane hit a seawall in front of the runway at San Francisco International airport, and initial information from the NTSB investigation shows that it was flying much too slowly in the final stages of the approach.
The plane's pilots have said in interviews with the NTSB that an electronic control known as an auto-throttle had been set to keep the plane flying at the proper speed, according to Hersman, and it remains unclear why the jet lost speed and why the pilots failed to notice the problem.
Hersman said the cockpit voice recorder showed that none of the three pilots on the flight deck said anything about speed until about 9 seconds before the crash. One of the pilots did raise a concern about "sink rate," or the speed of descent, prior to that, but Hersman did not provide further details.
The charred wreckage of the plane will be cut up and removed from the airport runway beginning on Thursday evening, Hersman said.
A final report on the crash will likely come in about a year.
In five detailed press briefings since the crash, Hersman has painted a picture of a flight crew that inexplicably failed to correct a doomed approach as the plane came in too low, too slow and off-center on a clear day with little wind. She has declined to speculate on the cause of the crash.
The briefings have drawn criticism from an airline pilots union and others, who say the release of so much information from flight recorders and other sources at an early stage of the investigation has unfairly suggested the pilots were at fault.
The pilot flying the plane when it crashed was still in training for the Boeing 777, and the instructor pilot who was in charge of the aircraft was on his first flight as a trainer.