A plane crash that killed 157 people in Ethiopia on Sunday morning is likely to aggravate concerns about the safety of one of Boeing’s newest commercial jets, aviation analysts say. The incident comes as the company faces intense scrutiny over another deadly plane crash involving the same 737 MAX 8 model.

In October, Lion Air Flight 610 in a new state-of-the-art MAX 8 plunged into the Java Sea shortly after takeoff from Jakarta, Indonesia, killing all 189 passengers and crew members. Boeing faces lawsuits filed by the families of at least two dozen victims.

In a memo to staff members days after that crash, Boeing chief executive Dennis Muilenburg wrote, “We’re going to learn from this accident and continue to improve our safety record.”

With the Addis Ababa investigation in its earliest phases, it is too early to know whether that crash was caused by the same problems that doomed the Lion Air flight in Indonesia. Ethio­pian Airlines said its investigators, the Ethio­pian Civil Aviation Authority and the Ethio­pian Transport Authority will conduct an inquiry “in collaboration with all stakeholders including the aircraft manufacturer Boeing” to determine the cause.

The 737 MAX 8 has been an important profit driver for Boeing since it was introduced in 2017. It is critical to Boeing’s broader international ambitions as it competes with Airbus, its European rival in the commercial airline business.

Boeing has delivered 354 of the jets globally and has 2,912 on order, according to market estimates maintained by Boyd Group International. The jet that crashed Sunday was one of five 737 MAX 8 planes operated by Ethiopian Airlines, which has 25 more on order.

In the United States, Southwest Airlines and American Airlines have 59 between their two fleets, with 304 on order. Southwest said it has been in touch with Boeing and plans to follow the investigation. It had not made any changes to its operations or inspection protocol as of Sunday, the airline said. American Airlines said it was monitoring the investigation but remained confident in the safety of its aircraft.

In a statement addressing the Ethiopia crash, Boeing said it has a technical team ready to provide assistance at the direction of the U.S. National Transportation Safety Board.

“Boeing is deeply saddened to learn of the passengers and crew on Ethiopian Airlines Flight 302, a 737 MAX 8 airplane,” Boeing said. “We extend our heartfelt sympathies to the families and loved ones of the passengers and crew on board and stand ready to support the Ethiopian Airlines team.”

Although it was too soon to determine the exact cause of the Ethio­pian Air crash, the plane, which was new, showed a similar flight path to the one in the Indonesia crash.

An Ethiopian Airlines executive said Sunday that the airplane had “no technical remarks” and was flown by an experienced pilot, Yared Getachew, 28, of Addis Ababa. He said the pilot mentioned he was having difficulty and wanted to return before he lost contact with air traffic control.

Aviation analysts say they are awaiting the final results of the Indonesian airline’s investigation and suggested that the results could negatively affect business for Boeing.

“If this has any relationship at all with the Lion Air incident, it’s a pretty good bet that the [Federal Aviation Administration] will move to have all 737 MAX aircraft inspected immediately,” said Mike Boyd, an aviation analyst with Boyd Group International.

Experts urged caution about drawing conclusions too quickly. Although details of the crashes — shortly after takeoff, at relatively low altitudes with erratic flight patterns — seem similar, the data is insufficient to conclude the same systems were at fault.

“Because of the apparent similarities between this and the Lion Air crash the questions naturally arise: Is this a similar crash?” said aviation consultant Scott Hamilton, managing director of Leeham Company, which provides aviation expertise and marketing analysis. “It may well turn out that there is a connection, but we don’t know that today.”

If the results of an inspection turn up significant design flaws in the 737 MAX, planes could be grounded worldwide, Boyd said.

China’s Civil Aviation Administration said in a statement Sunday that it has asked domestic airlines to temporarily ground all Boeing 737 Max jets. The move affected hundreds of flights on Monday in China, where 13 carriers operate more than 90 of the Boeing 737 Max 8 jets, domestic media reported. Chinese carriers have placed 180 orders for the model, Boeing said.

Cayman Airways also has suspended Boeing 737 Max 8 aircraft, Fabian Whorms, the company’s president and chief executive, said in a statement Sunday night.

The FAA said that it was planning to assist in the investigation of the crash, which killed everyone onboard, including eight Americans and 18 Canadians.

“The FAA is closely monitoring developments in the Ethiopian Flight 302 crash early this morning,” the agency said. “We are in contact with the State Department and plan to join the NTSB in its assistance with Ethiopian civil aviation authorities to investigate the crash.”

Boeing’s investors and customers seem to have shrugged off the issues related to the crash in Indonesia. Boeing had a banner year in 2018, notching $100 billion in revenue, amid accelerating international sales of its commercial jetliners. The 737 is the best-selling plane model in the company’s history. The commercial jetliner has gone through multiple iterations and upgrades since it first flew in 1967.

The crash in Indonesia turned a harsh spotlight on the MAX 8, Boeing’s latest update to its workhorse 737. A preliminary investigative report released in late November found that a malfunctioning sensor and an automated response from the aircraft’s software left pilots fighting furiously to control the aircraft before it careened into the Java Sea off Indonesia shortly after takeoff, killing 189 people.

The report found that a sensor measuring the plane’s “angle of attack” fed erroneous data into the plane’s flight-control system, at which point an automatic feature kicked in, sending the plane into a nosedive.

The report stopped short of assigning blame for the crash. However, multiple pilots organizations in the United States criticized Boeing after it disclosed that it had made certain changes to the MAX’s autopilot software — it added a new flight-control feature, the Maneuvering Characteristics Augmentation System (MCAS).

The updated software was meant to account for design changes to the 737 MAX and was supposed to make the plane operate as closely as possible to older 737 models despite having larger engines placed farther forward on the plane’s wings.

While the MCAS system was ostensibly added to make the plane safer, pilot unions in the United States said they had been left “in the dark” about the software update and criticized Boeing for failing to cover the new system in training sessions.

A Boeing spokesman did not respond to questions about whether the company had updated the MCAS system following the plane crash in Indonesia. Dennis Tajer, a spokesman for the Allied Pilots Association, a union that represents pilots at American Airlines, said Boeing executives initially told his members that the company had been looking at potential software-design issues, but they had not received word about whether the system had changed.

He said pilots at American Airlines still do not have flight simulators reflecting updates to the MAX 8.

“We have not been briefed on any changes to the software at this point,” Tajer said.

The lawsuits against Boeing in the Lion Air crash have zeroed in on claims raised by pilot organizations, which accused the company of including the new autopilot update in the 737 MAX8 without informing pilots. Among the first lawsuits was filed by an Indonesian man named H. Irianto, the father of an Indonesian doctor named Rio Nanda Pratama.

“At no relevant time prior to the crash of Lion Air Flight 610 into the Java Sea did Boeing adequately warn Lion Air or its pilots of the unsafe condition caused by the new “auto-diving” design of the 737 MAX 8 flight system,” Irianto alleged.

Boeing has not seen orders of new 737 models canceled as a result of the crash. Airlines considering future orders will be watching the situation in Ethiopia closely.

Two 737 MAX 8 commercial jets “have crashed shortly after takeoff. The airlines are going to be very interested to know whether this was a problem with the airplane, the training or both,” said Henry Harteveldt, an aviation-market analyst with Atmosphere Research.

“For airlines that are debating whether to order the [Boeing 737] MAX and how that would compare to other planes on the market," he said, "it’s very possible that tomorrow Airbus reps will get a few calls from people that had been considering Boeing.”

Hamilton said the cockpit voice recorders and flight data recorders would provide critical information on what transpired in the six minutes between the flight’s takeoff and the Ethiopia crash.

“It’s highly unusual for a new model airplane to have one accident -- let alone two in such a short period of time,” he said. “And, of course, investigators are going to look at the flight-tracker radar pattern, the circumstances. And one of the first things they’re going to zero in on: They’re going to look at MCAS performance, that’s going to be a natural thing for them to do.”

Gerry Shih in Hong Kong contributed to this report.