China 737 jet-crash clues awaited as black boxes arrive in U.S.

Investigators trying to figure out why a Boeing Co. 737-800 plunged to the ground in China last month could gain key clues within days from the jet’s black boxes, which were sent to the U.S. for analysis.

“I’d expect within a week the investigation team would have the information,” said Neil Campbell, a retired air-safety investigator at the Australian Transport Safety Bureau who worked on the Boeing 737 Max disaster in Indonesia in 2018. “For an accident like this, the recorders are critical.”

The two flight recorders, built to withstand high-speed impacts, have become central to solving the March 21 mystery considering the China Eastern Airlines Corp. flight disintegrated into more than 40,000 pieces when it slammed into a hillside.

Both Boeing and China Eastern have much hanging on an investigative breakthrough.

More than 200 of China Eastern’s Boeing 737-800 planes have been grounded for two weeks now because there was no obvious reason why the jet entered a sudden nosedive, killing all 132 people on board. And any evidence that clears or implicates Boeing could be critical for the U.S. manufacturer in China, where it’s working to resume deliveries of the 737 Max jet after a three-year halt.

Results from the black box analysis could come in one to two weeks, said Mike Poole, chief executive officer of Ottawa-based Plane Sciences, which helps countries develop air-accident investigation capabilities.

Poole said he’s never known data to be totally irrecoverable because of the force of a crash but said it still takes time to download it, convert it into useful information and analyze the details correctly.

China Eastern Flight 5735 from Kunming to Guangzhou was cruising at about 29,000 feet when it suddenly dived at high speeds. It slammed into a forested hillside about 100 miles from its destination.

Fears alleviated

The dispatch of the black boxes to the U.S. National Transportation Safety Board laboratory in Washington alleviates concerns, at least to some degree, that strained U.S.-China relations might hamstring the investigation into the disaster.

The exact status of the two recorders remains unclear. NTSB spokesman Eric Weiss declined to go beyond the investigation agency’s statements Friday.

The safety board has said it was assisting the CAAC with the download of the cockpit voice recorder at its lab in Washington, but wouldn’t be releasing any information about its contents. The NTSB also hasn’t commented on whether the download was successful.

The flight-data recorder, which captures hundreds of parameters monitoring an aircraft’s path and systems, was also brought to Washington by the Chinese, a person familiar with the process said last week.

The NTSB has declined to comment on whether it has downloaded the contents of the data recorder.

U.S team

Chinese authorities have also allowed a seven-person team sent by the NTSB to arrive in China, according to the official Xinhua News Agency. In another sign of cooperation, investigators have been given the green light to avoid quarantine and start work immediately if they limit contact with those outside the probe, the NTSB said.

Even when flight recorders are severely damaged, it’s still possible to extract information from the individual memory chips inside, said Joe Hattley, a former aircraft accident investigator who worked on the disappearance of Malaysia Airlines Flight 370 in 2014. He now teaches the subject at UNSW Sydney’s School of Aviation.

“I’d be surprised if we didn’t get everything from those flight recorders,” said Hattley.

Damaged module

The devices are designed to withstand the force of coming to a full stop within two meters from a collision at 500 kilometers per hour, according to retired investigator Campbell.

Photographs of one of the China Eastern black boxes indicates the module that houses the flight information sheared off its chassis.

In order to retrieve the data, investigators would need to open the module, access the circuit board, replace the cable and then plug it into a new chassis, said Campbell. That’s work only a handful of entities around the world, including the NTSB in the U.S., can do, he said.

“It’s not something you want to be doing in anger for the first time,” Campbell said. “It is important to have the right expertise and knowledge.”