Asiana Airlines San Francisco crash: piecing together the evidence

Investigators looking for clues to the Asiana Airlines crash landing at the San Francisco Airport found their first major piece of evidence Sunday: the “black boxes” containing the flight data recorder and the cockpit voice recorder.

The boxes – actually, they’re orange – are designed to tell experts exactly what was happening with the Boeing 777 airliner, including mechanical and electrical data, as well as what crew members said to each other as the aircraft approached Runway 28 Left.

What is obvious from photos and videos is that Flight 214 struck the sea wall at the end of the runway well short of the normal landing spot, which knocked off the tail section, one engine, and parts of the wings as the aircraft slammed down hard and slid to a stop to the left of and several hundred yards up the runway.

Eyewitnesses report seeing the aircraft in an unusually nose-high, tail-low attitude as it flew in low over the water, suggesting that the pilot flying the 777 – one of four flight crew members assigned to the 10-hour-plus flight from Seoul, South Korea – was trying to regain altitude.

The situation seemed to have surprised the flight crew. As they talked to flight controllers on the ground during the approach to San Francisco, they gave no indication of any difficulties nor did they alert passengers and cabin crew to the impending crash. Weather was not a factor. The approach and landing were being made visually and “hands-on,” which is not unusual.

On TV news shows Sunday, National Transportation Safety Board (NTSB) Chairman Deborah Hersman emphasized that it is very early in the investigation.

"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.

The system, called Glide Path, is meant to help planes land in bad weather. The weather was clear and sunny Saturday. Glide Path was far from essential for routine landings, and it was not unusual for airports to take such landing systems off line for maintenance or other reasons, Reuters reported, but pilots have grown to rely on the decades-old technology, which is designed specifically to prevent runway misses.

"The pilots would have had to rely solely on visual cues to fly the proper glide path to the runway, and not have had available to them the electronic information that they typically have even in good weather at most major airports," Capt. Chesley "Sully" Sullenberger, the former US Airways pilot who gained fame with a successful crash landing on the Hudson River in 2009, told the local CBS News affiliate.
 
 "What that means is that then the automatic warnings that would occur in the cockpit when you deviate below the desired electronic path wouldn't have been available either,” Captain Sullenberger said. “So we don't know yet if that's a factor in this particular situation, but that's certainly something they'll be looking at.”

Kevin Hiatt, chief executive of the Flight Safety Foundation and a former Delta pilot, said it was common for airports to take instrument landing systems off line for maintenance on clear days. Pilots use several other instruments and visual cues to land in clear conditions, Mr. Hiatt said.
 
 "All of those are more than adequate to fly an aircraft down for a successful landing on the runway," he told Reuters.

There were 307 people aboard Flight 214, 291 passengers and 16 crew members. The flight had originated in Shanghai and stopped in Seoul before flying on to San Francisco.

Two people aboard the plane died (both Chinese teenage girls). Of the 182 injured people taken to hospitals, at least 49 were in critical condition late Saturday. The remaining 133 had minor to moderate injuries, while many of the other passengers or crew members had more minor injuries that didn't require extra treatment, according to The Associated Press. Thirty of the passengers were children.

"I think when we look at this accident we're very thankful that we didn't have more fatalities and serious injuries and we have so many survivors," Hersman said on CNN's "State of the Union." "Really, very very good news as far as survivable accidents, which many accidents are."

The robustness of the 777 aircraft allowed many passengers to walk away from a catastrophic crash landing, other experts point out – including such safety features as multiple redundant systems, stronger seats, and the use of nontoxic materials in construction. Also, the Federal Aviation Administration now requires new aircraft models to be equipped and staffed to allow all passengers to exit within 90 seconds.

South Korean officials said the plane's passengers included 141 Chinese, 77 South Koreans, 61 Americans, three Canadians, three from India, one Japanese, one Vietnamese, and one from France, while the nationalities of the remaining three haven't been confirmed.