More than 40 countries have grounded their Boeing 737 MAX airplanes following the crash of Ethiopian Airlines Flight 302 that killed all 157 occupants on March 10.

Flight 302 was travelling from Addis Ababa, Ethiopia’s capital, to Nairobi, Kenya. The flight’s captain, Yared Getachew, reported a “flight control” issue shortly after takeoff, and requested to return back to the airport.

After six minutes into Ethiopians Airlines Flight 302, the plane disappeared from radars and crashed into the town of Bishoftu. Eye-witnesses from the scene told local authorities that “white smoke” and “strange noises” were coming from the plane.

Officials reported the recovery of the Ethiopian Airlines Flight 302’s “black box,” a tool implemented into airplanes as a cockpit voice and flight data recorder. The black box was sent to professionals in France for analysis.

The recent crash comes as the second involving a Boeing 737 MAX, the most popular commercial airplane, in the last five months. The other crash was the Indonesian Lion Air Flight 610 accident in Oct. 2018 that killed all of its 189 occupants.

Global safety regulars began to urge countries to cease flying the 737 MAX after an investigation into the recent crash found that both of the planes that crashed lacked the same optional safety features.

Boeing, the manufacturer of the 737 MAX, offer extra safety features for their models at an increased price, something both of the low-cost carriers, Ethiopian Airlines and Lion Air, opted against paying for.

Some of the optional features included passenger accommodations like premium seating and extra bathrooms, but others were more practical. A software update for the plane operational system was also available to consumers, as well as better navigational components.

According to tech reporter A.J. Dellinger, the optional software Boeing offered, “took readings from angle of attack sensors, which determined how much the plane’s nose is pointing up or down in relation to oncoming air.” Lacking this software feature may have contributed to both of the plane crashes, experts said.

Reputable insider sources told The New York Times that the FBI opened an investigation concerning the Boeing 737 MAX airplane certification process following the recent crash.

FBI representatives reportedly said they “could not confirm or deny” if any investigation regarding the matter was being conducted.

Indonesia’s national airline, Garuda Indonesia, cancelled an order of 50 Boeing 737 MAX airplanes, company spokesman Ikhan Rosan said on March 22.

The company, whose order would have totaled to an estimated $4.9 billion, comes as the first to cancel an order following the 737 MAX groundings.

Rosan told reporters that “Garuda passengers in Indonesia have lost trust and no longer have the confidence (in the plane).” Garuda Indonesia had already received one of the 50 planes at the time of cancellation.

Norwegian Air, a low-cost European airline which operates with a large fleet of the Boeing 737 MAX planes, said the company wants compensation from Boeing due to the recent groundings.

“It is obvious that the costs incurred by the temporary grounding of brand new aircraft should be covered by those who have made the airplane,” company spokesman Lasse Sandaker-Nielsen said in a press conference March 13.

Boeing invited hundreds of global experts, which included pilots and airplane regulators, to an “information session” in the upcoming weeks regarding the return of the 737 MAX for commercial use.

Boeing promised that a software patch to fix any underlying issues in the 737 MAX planes would be available to all airlines upon its completion.