How an Unearthed Black Box Could Crack the Boeing 737 Plane Crash Mystery

The chances of solving the urgent question of why China Eastern Airlines’ Boeing 737-800 jet hit the ground at the speed of a missile, instantly killing all 132 people on board, suddenly looks more hopeful.

Searchers have found one of the airplane’s black boxes at the crash site near Wuzhou, China–the cockpit voice recorder. Given the severity of the impact it is not surprising that, according to the Chinese searchers at the site, the outer casing is badly deformed but the hard discs storing the data are, according to a Chinese official, “also damaged to some extent, but relatively complete.”

While the cockpit recorder data will be valuable in giving an audio record of many alarms sounding and exchanges between the pilot and copilot, it is of far less help in identifying what was happening to the airplane itself. That information is stored in real time detail in the other black box, the flight data recorder, which is yet to be found. Given that this recorder is better protected because it is in the rear of the airplane, not the nose, if found it will provide the kind of definitive technical picture that would be conclusive in an investigation.

The last time data was retrieved from a black box in such a critical condition was following the crash of Ethiopian Airlines Flight 302 in March 2019. That was the second fatal crash of the latest 737 model, the 737MAX, a catastrophe that led to the grounding of the entire fleet of those jets. And although those two crashes were caused by a system not installed in China Eastern’s Boeing 737-800, the end result was identical: a horrific, near vertical dive into the ground at around 700mph. The forces at impact on the flight recorders of both types of 737 would have been the same.

The MAX disasters both happened during the flight’s climb-out after take off, whereas the Chinese pilots were about to begin their descent after a completely uneventful commuter flight from Kunming to Guangzhou in good weather. They were then so suddenly crippled that they issued no May Day emergency call.

In the case of the Ethiopian crash the black boxes were sent to one of the world’s most highly regarded teams of investigators, the Bureau d’Enqetes et d’Analyses, BEA, a laboratory in Paris staffed by French air crash investigators. The French technicians were able to download the flight recorder data within three days of receiving it–with the damning evidence that, just as in the first 737 MAX crash six months earlier in Indonesia of a Lion Air jet, rogue software had taken control from the pilots and, overriding their desperate efforts to recover, had forced the jet into the death dive.

China has invested heavily in its air safety regime, taking cues from both the U.S. National Transportation Board’s technology and the example of the BEA. At the moment the Chinese recorder is being handled at a lab run by their safety officials in Beijing. At the same time, U.S. Transportation Secretary Pete Buttigieg said he was encouraged by the news that investigators from the NTSB have been invited to China to join the investigation.

After the crash, China Eastern immediately grounded its fleet of 60 737-800s. In fact, China operates 24.6 percent of the world’s fleet of that model, the largest of anywhere in the world. (North American airlines fly 22.8 percent of the fleet and Europe 22.1 percent, according to data provided by Aviation Week). China is the world’s fastest growing domestic air travel market: although the Covid-19 pandemic initially caused air travel to tank, China recovered quicker than many other nations and now there are more than 12,500 domestic flights a day.

But because the Chinese are so new to the utility of intercity jet travel, and because until now China has had an exemplary record of air safety, the China Eastern catastrophe has brought home how one crash, while it may not be statistically very significant, can deliver a huge blow to public confidence. Given that this crash has no obvious precursors in the history of the 737-800, a jet that has been as reliable as it is ubiquitous, the Chinese authorities are now under enormous pressure to show that they can carry out a successful investigation.