The trouble appeared to begin almost immediately after take-off. The pilots told air traffic controllers that they were having technical problems. And the plane seemed to repeatedly climb and dive before a final plunge.
Two eerily similar scenes have played out in recent months for Boeing’s brand-new 737 MAX jets: on Sunday, when an Ethiopian Airlines flight crashed just after taking off from Addis Ababa, killing 157 people, and in October, when a Lion Air disaster in Indonesia left 189 dead.
The Ethiopian crash occurred just outside the country’s capital, leaving a smoking crater where investigators combed over the grim scene. Much about the cause of the crash remains unknown and will take weeks to investigate, and Boeing and the National Transportation Safety Board are sending teams to the site.
But the rarity of two planes of the same model going down in such a short time span has caught the attention of pilots, passengers, engineers and industry analysts.
For Boeing, the questions go to the heart of its business, as the 737 class is a workhorse for airlines, and the single-aisle 737 MAX has been the company’s best-selling plane.
Ordered the grounding
By the end of January, Boeing had delivered over 350 737 MAX jets since putting them in service in 2017. They have a list price of around $120 million, the company said, and around 5,000 more are on order.
“There’s a whole lot of questions and not a lot of answers,” said John Cox, former executive air safety chairman of the Air Line Pilots Association in the US and now chief executive of Safety Operating Systems, a consulting firm.
Some airline and national officials are not waiting for answers. China has ordered the grounding of 737 MAX planes, and Cayman Airways said it was grounding its two new jets.
The business of building and selling jets is brutally competitive, and the 737 MAX was Boeing’s answer to an update that Airbus, the giant European aircraft manufacturer, unveiled for its popular A320 jet that made it more fuel-efficient.
Boeing and Airbus have jockeyed for dominance for years. About 10,000 planes from Boeing’s 737 family are in service. Airbus’ A320 family has 8,000.
Many airlines rely on these kinds of planes as linchpins of their fleets. They are designed to efficiently serve short and medium-haul routes and carry about 200 passengers.
Boeing’s response to its rival’s move was a more efficient engine, but the MAX engine was bigger than earlier versions.
To address this challenge, Boeing updated the software for the flight control system. After the Lion Air crash, some US aviation authorities said the change had not been adequately explained to pilots.
But in light of the Indonesian disaster, pilots have since been informed by Boeing and regulatory agencies of the MAX’s new system, and airlines have provided training classes on it.
Whether Ethiopian Airlines, which, unlike Lion Air, has a strong safety reputation, carried out that training was not immediately known.
Boeing installed the system on the new 737s as part of the “control law” — commands the plane’s flight-control computer issues that bypass the pilots.
On the Lion Air flight, the swings up and down may have come about as pilots repeatedly tried to keep that system from pushing the nose of the aircraft down and putting it into a fatal dive.
The pilots lost their battle after about 12 minutes of flight.
While a malfunction of that system is a possibility in the Ethiopian flight, which lasted about six minutes and included a shorter series of swings, early information is still too sketchy to draw conclusions.
And what is known so far does not rule out pilot error or the malfunction of a completely separate system.
Robert Stengel, an expert on flight control systems and a professor of engineering, said it was not clear whether the rocking trajectory of the Ethiopian jet was caused by a malfunctioning control system or pilots trying to fly the plane manually “while distracted by some other emergency”.
Stengel thinks no conclusions can be reached without more information. Broad similarities in the two crashes could not help but affect the flying public, he said. “If you’re simply looking at circumstantial evidence, that gives you pause, doesn’t it?” Stengel said.
“That’s not a deep technical observation — that’s just human nature.”
The short, deadly flight in Ethiopia may call for immediate action while investigators determine if there is a common thread, said Jim Hall, a former chairman of the National Transportation Safety Board. “The possibility of grounding the aircraft would be one of the options … the regulators and investigators are looking at.”
Analysts agree that Wall Street is not going to be kind to Boeing stock. And whatever hit its shares take will weigh heavily on the Dow Jones industrial average, which, in recent years, has been lifted by Boeing’s success.
Boeing shares have tripled since the presidential election in 2016, making it the highest-priced stock in the Dow. From November 8, 2016, through Friday, the Dow added more than 7,000 points, and Boeing’s rise accounted for nearly 30 per cent of its gain.
Richard Aboulafia, an aviation analyst, cautioned against reading too much into the immediate reaction in the shares. “I’ve learned from bitter experience not to look at the stock prices in the aftermath of a crash,” he said.
Aboulafia predicted that any pullback was likely to be a short dip, given the company’s recent strength.
At the close of trading on Friday, Boeing was valued at nearly $239 billion, with a stock price above $422 a share.
The company, which employs 150,000 people, took in just over $100 billion in 2018, with profit for the year topping $10 billion.
By James Glanz and Zach Wichter