LEILA FADEL, HOST:
Air disaster investigators from the U.S. are in China this week. They've arrived to help figure out what happened to a Chinese flight that crashed last month, killing all 132 people on board. NPR's Emily Feng is in Beijing.
EMILY FENG, BYLINE: What stands out the most about China Eastern Flight 5735 are its last moments. On March 21, it plunged more than 7,000 feet in a minute, pulling up slightly but then shooting down again, hitting the ground nose first at near supersonic speeds. The wreckage of the plane was scattered across a tropical hillside in southern China, some fragments buried up to 60 feet deep. Here's David Yu, a Shanghai-based aircraft appraiser.
DAVID YU: Well, generally speaking, look; if you're a normal aircraft and you basically shut off all the engines, the plane is actually built to basically glide, OK?
FENG: So that 90-degree angle at which the plane hit the ground is highly unusual. Chinese air crash investigators found nearly 50,000 fragments, including the plane's two flight recorders. Whatever cockpit voice recordings and flight data can be gleaned from those recorders are now being analyzed in Beijing and at the Washington, D.C., labs of the National Transportation Safety Board, a U.S. government investigation agency.
DANIEL ADJEKUM: And there's a reason why they should have access to this data because you want your investigation to be global, and it has to be credible.
FENG: This is Daniel Adjekum, an aviation safety professor at the University of North Dakota. The plane that crashed was a U.S.-designed Boeing 737-800 plane, so American investigators have an interest in assessing whether this was a plane failure. But so far, Chinese investigators say all hypotheses are still on the table.
ADJEKUM: Maybe it was such a catastrophic loss of control that they were struggling to regain control of the aircraft. A second option is that the crew were incapacitated. The third possibility, which is remote, is that it could potentially have been an aircraft-assisted suicide. I'm not saying that's what happened, but you don't rule it out.
FENG: Last week, a team of National Transportation Safety Board investigators were able to fly to China and skip China's mandatory three-week quarantine to immediately begin helping with the Chinese investigation. And that means we could have more answers soon about China's worst civil aviation disaster in two decades.
Emily Feng, NPR News, Beijing. Transcript provided by NPR, Copyright NPR.