Black boxes may unlock secrets

BEIJING • The recovery of the second black box from the wreckage of a China Eastern Airlines jet potentially gives investigators their best opportunity to find out why the plane carrying 132 people entered a high-altitude nosedive and speared into the ground.

The flight data recorder, which was buried some 40m from the main crash site near Wuzhou in southern China, was unearthed on Sunday morning.

State media reported the device has been sent to Beijing for analysis. Much now depends on how well the black box withstood the impact of the March 21 crash.

The Boeing 737-800 appears to have largely disintegrated, and more than 33,700 pieces of debris have been recovered.

Chinese state media said the crash left a crater 20m deep.

Some parts of the data recorder were severely damaged, according to the Civil Aviation Administration of China (CAAC), possibly complicating the task of retrieving and deciphering any information inside.

Such boxes store hundreds of flight parameters - from speed and altitude to flap positioning and heading - that help investigators recreate the final fateful moments before a crash.

Investigators found the plane's cockpit voice recorder last Wednesday and aim to use data from the two boxes to find out what went wrong. Officials have not ruled out the possibility that the first black box has been badly damaged.

Countries leading an aircraft accident investigation must produce a preliminary report within 30 days of the incident, according to United Nations standards governing the aviation industry. A full report is expected within 12 months.

Flight MU5735 from Kunming was cruising at about 8,840m and some 160km from its destination in Guangzhou, southern China, when it suddenly went into a steep descent. Over the next 1 minute and 35 seconds, the plane lost altitude in a near vertical dive, which took it almost to the speed of sound.

The plane halted its descent for some 10 seconds, and climbed a little, before plummeting again and slamming into a hillside.

All 132 people on board, including nine crew members, were killed. China said on Saturday it had not found any evidence of explosive materials in the wreckage of the plane.

Hundreds of people, including firefighters, doctors and investigators - some dressed in full-body protective suits - remained at the scene of the tragedy on Sunday recovering human remains and the wreckage of the plane.

One week after the incident, politics risks complicating the probe into the tragedy. With ties between Washington and Beijing at their lowest ebb in years, the crash of a United States-made plane run by a Chinese, state-owned airline has turned the two arch rivals into reluctant bedfellows.

But the depth of the collaboration, or the ability of the two sides to work together because of Covid-19 restrictions in China, remains unclear.

The US National Transportation Safety Board (NTSB) last Saturday declined to comment on a report on Twitter that said an Air China plane was heading to the US as part of the investigation.

The plane was headed to Washington to "pick up" NTSB investigators, the China Aviation Review wrote in a tweet. The NTSB is assisting the probe under a UN treaty, but has not announced plans to send any investigators to China.

"The NTSB and the CAAC continue to coordinate on the investigation into the China Eastern B-737 accident," the US agency said. "This includes coordination on potential travel of investigators to China or the US as necessary."

BLOOMBERG, AGENCE FRANCE-PRESSE