NTSB: Black Boxes Recovered in Asiana Airlines Crash

National Transportation Safety Board Chair Deborah Hersman said Sunday that it's too early to draw conclusions behind what caused Saturday's dramatic plane crash at the San Francisco International Airport, but the flight data recorders have been recovered and are being examined.

The black boxes are really important to our investigators," Hersman said on CBS' "Face the Nation." "The cockpit voice recorder can give us insight into what's going on with the crew in the cockpit. The flight data recorders can give us insight into what's happening with the aircraft."

Hersman said it is too early to blame faults at the airport for the crash. For example, the glide path landing system at the airport has been out since June, and there has been on-going construction.

"What's important to note is that there are a lot of tools available to pilots," Hersman said. "The glide slope indicator is just one of those tools. There's information that's more primitive, things like lights that can tell you whether you're lined up too high or too low."

There are also more sophisticated tools, such as GPS, that also help planes land, and the NTSB will be looking at all aspects behind the crash.

Hersman said that Sunday is the NTSB's first full day on the scene of the crash, and there will be a great deal of work to do before a conclusion is reached about its cause.

She refused to speculate about whether it was "a miracle" that so many people walked away from the dramatic crash.

The Boeing 777 had 291 passengers aboard. At least two people were killed and 182 injured, but another 123 did not require transportation to hospitals, reports said.

"What I will tell you is there was significant damage on the aircraft," said Hersman. "You've seen pictures of the burned fuselage, but inside the aircraft there's significant structural damage. We are very thankful there weren't more fatalities and serious injuries."

She said that the crash was a "survivable accident," but the NTSB's thoughts went out to victims' families and those people still recovering.

"We saw so many people walk away and what's important for people to understand that airplane crashes, the majority of them, are survivable," said Hersman.

The crashed wide-body jet was operated by Asiana Airlines based out of Seoul, South Korea. In addition to the passengers, the plane had 16 crew and staff aboard. The flight originated in Shanghai China and stopped in Seoul before making its way to San Francisco for its final destination.