Airline stocks pared their early losses Monday, as Boeing Co. shares rebounded from their worst levels, after a deadly crash involving the aerospace giant’s 737 Max 8 aircraft in Ethiopia, the second fatal accident involving the aircraft in six months.

AVA- Boeing shares BA, -5.23% slid more than 11% premarket but were down about 6.9% in official trade, on the news that the aircraft operated by Ethiopian Airlines crashed shortly after taking off from the capital of Addis Ababa, killing all 157 people on board. In October, the same plane, operated by Indonesia Lion Air, crashed into the sea, killing all 189 passengers on board. China’s civilian aviation authority has ordered all airlines to ground Max 8 planes, while Ethiopian Airlines has grounded its entire fleet of the model.
“It may take weeks for an initial report on the causes of the Ethiopian crash, so we are reluctant to draw conclusions about the possible impact,” wrote JPMorgan analyst Seth Seifman in an early note to clients. “We detected no additional disclosures in Boeing’s 10-K resulting from the Lion crash.”
UBS analysts agreed it was too soon to draw conclusions, but said the similarities between the two crashes were “hard to ignore.” In both cases, pilots requested approval to return to their departure airport within minutes of take-off, analysts led by Myles Walton wrote in a note.
Walton noted that the Maneuvering Characteristics Augmentation System (MCAS) in the 737 Max, a safety feature that is supposed to activate at high angles of attack, was the key focus in the Lion Air crash. That led to an Airworthiness Directive that called specific attention to the system, he wrote.
“The MCAS system doesn’t activate until the flaps used for takeoff are retracted, so in the case of Lion Air, for example, issues seemed to arise around the 2-3min mark. This appears to be a similar timeline to Ethiopian 302. It is unclear if additional training on MCAS was conducted at Ethiopian after the Lion Air accident,” he wrote.
Boeing said it was “deeply saddened to learn of the passing of the passengers and crew” on the Ethiopian Airlines airplane. In a statement posted on its website, the company said it is planning to send a technical team to the crash site to help Ethiopian and U.S. investigators.
The U.S. Federal Aviation Administration (FAA) said it is closely monitoring developments.
“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,” the FAA said in a statement.
The 737 is the best-selling airliner ever, and the Max is a newer version that Boeing says has a more fuel-efficient engine. The aircraft is a key part of Boeing’s effort to compete with rival Airbus.
Deliveries of the plane total about 350, according to Boeing, and it has been purchased by many airlines, including Southwest Airlines Co. LUV, -0.66% American Airlines Group Inc. AAL, +0.28% and United Continental Holdings Inc. UAL, -0.54% The company said in December that it has captured more than 5,000 orders since launch.
Southwest shares fell 1.6%, even as the carrier expressed confidence in its Boeing aircraft and said it has no plan to change operations. It also told customers that if they changed flight plans to avoid flying on 737 Max planes, they would be responsible for any fare differences.
“As Southwest operates a fleet of 34 Boeing 737 MAX 8 aircraft, we have been in contact with Boeing and will continue to stay close to the investigation as it progresses,” said a spokesman for the Southwest. “We don’t have any changes planned to our operational policies or procedures.”
United Continental said it sends its sincerest condolences to the families and loved ones of those on board the Ethiopian flight. A spokesperson said the airline currently has 14 Max-9 aircraft, but no Max-8 or Max-10 aircraft in its fleet.
The stock was down 0.1%.
American said it has 24 Max 8 aircraft in a fleet of nearly 1,000. The carrier also extended condolences but cautioned that it is too early to determine the cause of the accident.
“Our Flight, Flight Service, Tech Ops and Safety teams, along with the Allied Pilots Association (APA) and Association of Professional Flight Attendants (APFA), will closely monitor the investigation in Ethiopia, which is our standard protocol for any aircraft accident,” the company said in a statement.
American shares were up 0.8%. Jetblue Airways Corp. shares JBLU, +1.77%JBLU, +1.77% rose 0.4% and Delta Air Lines Inc. DAL, +2.96%  shares were up 1.9%. The US Global Jets ETF JETS, +0.31%  was down 0.1% and the NYSE Arca Airline index XAL, +0.29%  was up 0.4%.
Boeing’s stock was accounting for about 235 points off the Dow Jones Industrial Average DJIA, +0.61%
DJIA, +0.61% The S&P 500 SPX, +1.10%  was up 0.7%.