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Forensic experts work at the site of an Ethiopian Airlines crash at Hama Quntushele village, near Bishoftu, on March 16, 2019.TONY KARUMBA/AFP/Getty Images

Investigators into the Boeing 737 Max crash in Ethiopia have found striking similarities in a vital flight angle with an airplane that came down off Indonesia, a source said, piling pressure on the world’s biggest plane maker.

The Ethiopian Airlines disaster eight days ago killed 157 people, led to the grounding of Boeing’s marquee Max fleet globally and sparked a high-stakes inquiry for the aviation industry.

Analysis of the cockpit recorder showed its so-called “angle of attack” data was “very, very similar” to the Lion Air jet that came down off Jakarta in October, killing 189 people, a person familiar with the investigation said.

The angle of attack is a fundamental parameter of flight, measuring the degrees between the air flow and the wing. If it is too high, it can throw the plane into an aerodynamic stall.

“If that’s the case, that does raise the possibility that there is a similar occurrence between the Lion Air and Ethiopian Airlines accidents,” said Clint Balog, a Montana-based professor at Embry-Riddle Aeronautical University. Even then, it was too early to draw firm conclusions, he added.

A flight deck computer’s response to an apparently faulty angle-of-attack sensor is at the heart of the ongoing probe into the Lion Air crash.

Ethiopia’s Transport Ministry, France’s BEA air accident authority and the U.S. Federal Aviation Administration (FAA) have all pointed to similarities between the two disasters but safety officials stress the investigation is at an early stage.

“Everything will be investigated,” Ethiopian Transport Ministry spokesman Musie Yehyies told Reuters.

Both planes were 737 Max 8s and crashed minutes after takeoff with pilots reporting flight control problems.

Under scrutiny is a new automated system in the 737 Max model that guides the nose lower to avoid stalling, while in the Lion Air case Boeing has raised questions about whether crew used the correct procedures.

Lawmakers and safety experts are asking how thoroughly regulators vetted the system and how well pilots around the world were trained for it when their airlines bought new planes.


With the prestige of one of the United States’ biggest exporters at stake, Boeing has said the Max series is safe, though it plans to roll out new software upgrades in days.

The fix was developed in the aftermath of the Indonesia crash when regulators suggested false sensor data could cause a system known as MCAS (Maneuvering Characteristics Augmentation System) to overreact and make the jet hard to control.

Although the 737 has two sensors, Reuters first reported in November that the system for preventing stalls only tracks one of them at a time because regulators assumed risks of a mishap were small and would be further reduced by a trained crew.

The two sensors are compared only by certain 737 systems.

Pressure is growing on the FAA to explain the way it approved the upgrade of earlier models after a U.S. flight attendants union last week called for a “certification review”.

Boeing has halted deliveries of its best-selling model that was intended to be the industry standard but is now under a shadow. Developed in response to the successful launch of the Airbus A320neo, some 370 Max jets were in operation at the time of the Ethiopian crash, and nearly 5,000 more on order.

After a 10 per cent drop last week that wiped nearly $25-billion off its market share, Boeing stock slid about 2.2 per cent on Monday.

Weekend media reports heaped further pressure on Boeing and its domestic U.S. regulator.

The Seattle Times said the company’s safety analysis of the MCAS system had crucial flaws, including understating power.

The Wall Street Journal reported that prosecutors and the U.S. Department of Transportation were scrutinizing the FAA’s approval of the Max series, while a jury had issued a subpoena to at least one person involved in its development.

Boeing and the FAA declined to comment on that.

Last week, sources told Reuters investigators found a piece of a stabilizer in the Ethiopian wreckage set in an unusual position similar to that of the Lion Air plane.


Ethiopia is leading the probe, though the black boxes were sent to France and U.S. experts are also participating.

Investigators were expected to select a handful of the roughly 1,800 parameters of flight data in their initial review, including those thrown up by the Lion Air investigation, before analyzing the rest in coming weeks and months.

Ethiopian, U.S. and French investigators as well as Boeing were expected to inspect the preliminary data, but only Ethiopian authorities have access to the sensitive voice tapes.

The inquiry is crucial to give some closure to families of victims, who came from nearly three dozen countries.

It also has huge financial implications. The Max is Boeing’s best-selling model, with a backlog of orders worth well over $500-billion at a list price of $121-million each.

Norwegian Airlines has already said it will seek compensation after grounding its Max aircraft, and various companies are reconsidering orders.

Boeing’s main rival Airbus has seen its stock rise 5 per cent since the crash, but cannot simply pick up the slack given the complicated logistics of plane-building. For now Boeing continues to build planes while keeping them parked.

Some airlines are revising financial forecasts, too, given the Max had been factored in as providing around 15 per cent maintenance and fuel savings.

WestJet Airlines on Monday became the second Canadian carrier to suspend its 2019 financial projections, following Air Canada in light of the 737 Max groundings.

Boeing Chief Executive Dennis Muilenburg sought to allay some fears, saying the company was finishing a software update and pilot training revision “that will address the MCAS flight control law’s behaviour in response to erroneous sensor inputs.”

The agony for families of the dead in Ethiopia has been compounded by their inability to bury remains. Charred fragments are all that remain and DNA testing may take months.

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