Investigators probing the Boeing 737 MAX crash in Ethiopia have found similarities in vital flight angle data with an airplane that came down off Indonesia, a source said, hiking pressure on the world’s biggest planemaker.
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 that 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.
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 said data shows similarities between the two disasters.
Both planes were 737 MAX 8s and crashed minutes after take-off 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.
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 shortly.
The fix was developed in the aftermath of the Indonesia crash when regulators reported false sensor data could cause a system known as MCAS (Maneuvering Characteristics Augmentation System) to over-react and make the jet hard to control.
Boeing has halted deliveries of its best-selling model that was intended to be the industry standard but is now under a shadow. There were more than 300 MAX airplanes in operation at the time of the Ethiopian crash, and nearly 5,000 more on order.
After a 10 percent drop last week that wiped nearly $25 billion off its market share, Boeing stock slid about 2.3 percent on Monday to $370.
Weekend media reports heaped further pressure on Boeing.
The Seattle Times said the company’s safety analysis of the MCAS system had crucial flaws, including understating power.
It also said the U.S. FAA followed a standard certification process on the MAX rather than extra inquiries. The FAA declined to comment, but has said the process followed normal process.
The Wall Street Journal reported that prosecutors and 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 that 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.
It was unclear how many of the roughly 1,800 parameters of flight data and two hours of cockpit recordings, spanning the doomed six-minute flight and earlier trips, had been taken into account in the preliminary Ethiopian analysis.
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 re-considering orders.
Boeing’s main rival Airbus has seen its stock rise 5 percent since the crash, but cannot simply pick up the slack given the complicated logistics of plane-building.
Some airlines are revising financial forecasts, too, given the MAX had been factored in as providing around 15 percent maintenance and fuel savings.
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 behavior 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.