More than 300 Boeing 737 MAX 8 and MAX 9 passenger jets around the world have been taken out of service following two fatal crashes over the past five months in Ethiopia and Indonesia that killed almost 350 people in all. The causes of both crashes are under investigation. One of the biggest unanswered questions: Was the plane’s software to blame?
WHAT WE KNOW
Boeing has stopped delivery of all new MAX jets to its customers after the crash in Ethiopia on March 10 that killed 157 people. Satellite data gathered from the Ethiopian Airlines flight and evidence from the crash site showed similarities with a Lion Air accident in Indonesia, prompting the U.S. Federal Aviation Administration (FAA) to ground all MAX jets.
Investigators have found strong similarities in the ‘angle of attack’ data recorded by the Ethiopian Airlines flight cockpit recorder and data from the Lion Air jet, a person familiar with the matter said. – Graphs of the two sets of data are “very, very similar,” the person said. The angle is a key flight parameter that must remain narrow enough to preserve lift and avoid an aerodynamic stall.
A flight deck computer’s response to readings from an apparently faulty angle-of-attack sensor is at the center of an ongoing probe into the Lion Air disaster. Investigators who verified data extracted from the black box recorders of the Ethiopian plane have found “clear similarities” with the doomed Lion Air flight,
the French BEA air accident authority also said. Investigators have found a piece of a stabilizer in the wreckage of the Ethiopian jet with the trim set in an unusual position similar to that of the Lion Air plane, two sources familiar with the matter said. The investigation turned on Tuesday to the secrets in the Ethiopian flight’s cockpit voice recorder, as the words of Captain Yared Getachew and First Officer Ahmed Nur Mohammed could reveal what led to the crash.
Black box data was downloaded in France but only Ethiopian experts leading the probe have heard the dialogue between Getachew, 29, and Mohammed, 25. The data was back in Addis Ababa on Tuesday, sources familiar with the probe told Reuters. The pilot of the Ethiopian flight had reported internal control problems and received permission to return. The pilot of the Lion Air flight, which crashed on Oct. 29 with the loss of all 189 people on board, had also asked to return not long after taking off from Jakarta.
Following the Lion Air crash, Boeing said it was preparing a software upgrade for the jets. After the Ethiopia crash, the company said it would deploy that upgrade across the fleet in the coming weeks. Boeing maintains its new, fuel-efficient jets are safe, but supported the FAA decision to ground them. Fearing a financial hit and brand damage, investors have wiped around $29 billion off the company’s market value.
U.S. lawmakers said the planes could be grounded for weeks to upgrade and install the software in every plane. Boeing plans to release upgraded software for its 737 MAX in a week to 10 days, sources familiar with the matter said on March 16. No lawsuits have been filed since the crash of Ethiopian Airlines Flight 302, but some plaintiffs’ lawyers said they expect that Boeing will be sued in the United States.
Investigators are expected to release a preliminary report based on information they glean from the data and cockpit recordings captured by the two black boxes. A decision will be made by countries about whether and when to lift the grounding of the Boeing jets based on that information. Ethiopian Airlines said on March 16 that DNA testing of the remains of the passengers may take up to six months.
Lawmakers and safety experts are questioning how thoroughly regulators vetted the MAX model and how well pilots were trained on new features. U.S. federal prosecutors and the U.S. Department of Transportation are scrutinizing how carefully the MAX model was developed, two people briefed on the matter said. The U.S. Justice Department is also looking at the Federal Aviation Administration’s (FAA) oversight of Boeing, one of the people said. The FAA has said it is “absolutely” confident in its vetting.