As aviation officials continued investigating an airplane crash that killed more than 150 people in Ethiopia on Sunday, U.S. airlines faced uncertainty among travelers about whether they ought to worry about boarding a flight on the particular plane in question.
It’s too soon to say whether there is any connection between the Ethiopian Airlines crash on Sunday and the one that sent a Lion Air flight leaving Indonesia’s capital into the Java Sea last year, aviation experts said.
On Monday, U.S. airlines worked to reassure customers and aviation experts cautioned against reacting while the cause of the crash was unknown.
The Federal Aviation Administration said it was continuing to investigate. “If we identify an issue that affects safety, the FAA will take immediate and appropriate action,” the agency said in a statement.
As of Tuesday, France, Ireland, Germany, Britain, Singapore, China, Australia, Oman and Indonesia were among the countries that had prohibited the 737 Max 8 model from flying.
Boeing said it was working with investigators and regulators to understand the accident.
“The investigation is in its early stages, but at this point, based on the information available, we do not have any basis to issue new guidance to operators,” the company said in a statement.
But similarities between the crashes, such as the fact that both happened shortly after takeoff, and news that many airlines around the world had halted flights on the aircraft, left some travelers wary.
When Randy Noland, who said he flew 40,000 miles in January alone for his job overseeing global sales for Hemisphere GNSS, tweeted at United Airlines with concerns, the carrier said it understood but did not have the particular model involved in the crashes, the Boeing 737 Max 8, in its fleet.
“Our pilots are properly trained to fly the 737 MAX 9 aircraft safely,” the airline wrote.
Noland, of Scottsdale, Ariz. felt like “it was a bit of a plastic answer.”
“If United is certain the Max 9 doesn’t have whatever issues the Max 8 might have, they should be transparent about how and why they’re confident in that,” he said.
That wait for information prompted many travelers to question airlines on Twitter about whether they used the aircraft.
A Twitter user who said she was worried about an upcoming flight with her grandmother asked Delta Air Lines if it flew the Boeing 737 Max 8, and if so whether it would offer refunds so travelers could switch to another flight. Delta said it does not have the Max 8 in its fleet. American Airlines has 24 of the planes, with more on order. It was continuing to fly the plane, the airline said.
“We have made clear that the Boeing 737 MAX aircraft is safe and that our pilots are properly trained to fly the MAX aircraft safely,” United spokeswoman Rachael Rivas said in an email.
One Twitter user said his flight on a Southwest Airlines Boeing 737 Max 8 Monday morning was the first time he’d felt nervous flying in 25 years, and asked the carrier to explain how it was mitigating risk.
Southwest Airlines, which built its fleet around the Boeing 737, has 34 of the Max 8 aircraft in its fleet. The airline, which continued to use the plane, often responded with reassurances, and instructions for how to check the type of aircraft scheduled to handle a particular flight.
Many carriers provide that information online and during the booking process, as do flight-tracking websites like FlightAware.
“We have been in contact with Boeing and will continue to stay close to the investigation as it progresses. We remain confident in the safety and airworthiness of our fleet of more than 750 Boeing aircraft,” Southwest spokesman Chris Mainz said in an email.
It is rare for a new aircraft model to have two catastrophic accidents within months of each other, said Anthony Brickhouse, associate professor of Aerospace and Occupational Safety at Embry-Riddle Aeronautical University.
“It definitely catches your attention,” he said.
But he and other experts cautioned against assuming the incidents are related.
“To my knowledge, there is no evidence that indicates an unsafe condition,” John Cox, CEO of aviation consultancy Safety Operating Systems, said in an email. “As of now, I am still comfortable with the Max flying. No other version of the 737 has been affected.”
While investigations into aircraft accidents often take months to complete, if the manufacturer and regulatory authorities determine there could be a broader problem with the aircraft, they would act immediately — potentially within days, Brickhouse said.
Flight data and voice recorders were recovered, which will help the investigation, experts said.
Speculation “doesn’t help anyone,” said Robert Mann, a New York-based airline industry consultant.
“If (the FAA) is still waiting on an information-based approach, that’s what we should be doing,” he said.
Despite the apparent similarities between the Lion Air and Ethiopian Airlines accidents, the FAA said Monday it has not “been provided data to draw any conclusions or take any actions.”
The agency also said it plans to announce required changes to the aircraft’s flight control system, developed in response to the Lion Air crash, by April.
Indonesian officials said the aircraft received faulty information from one of its sensors. While many factors likely played a role in the crash, that could have made the plane repeatedly start to dive, according to the FAA. At the time, Boeing and the FAA sent alerts to airlines reminding pilots of the proper procedures to handle that situation.
The changes expected in April are meant to reduce the chances that a similar failure could lead to an accident, and include improving the way the system designed to keep the aircraft from stalling is activated and making it easier for pilots to retake control, the FAA said.