"We just arrived on scene a few hours ago,” Ms. Hersman said on ABC's "This Week." “We have a lot of work ahead of us. We have teams that will be looking at aircraft operations, at human performance, survival factors, and we'll be looking at the aircraft. We'll be looking at power plants, systems, and structures. And so we really want to make sure we have a good understanding of the facts before we reach any conclusions."
Hersman said investigators expect to speak with the pilots “in coming days.”
At a news conference in Seoul, Asiana Airlines President Yoon Young-doo emphasized that the four South Korean pilots were highly experienced – three of them with more than 10,000 hours of flight time and the fourth with nearly that many.
But absent any indication of mechanical failure, the investigation will have to focus on pilot performance, including the possible role of fatigue after such a long overnight flight.
Reuters reports that an automated instrument landing system had been turned off at the San Francisco airport due to construction.