After two deadly crashes and nearly two years of investigation, the Federal Aviation Administration (FAA) has cleared Boeing's 737 Max jet for flight.

The U.S. air safety agency announced the move early Wednesday. It said the decision comes after a complete and methodical 20-month review process.

Air safety agencies around the world grounded the 737 Max in March 2019 following the crash of an Ethiopian Airlines flight. That happened less than five months after another Max, flown by Indonesia's Lion Air, crashed in the Java Sea. A total of 346 people on both planes were killed.

On Wednesday, FAA chief Stephen Dickson signed an order to cancel the grounding, the longest in commercial aviation history. U.S. airlines are permitted to fly the Max after the Boeing Company changes computers and computer software on each plane. In addition, the company will offer training to pilots on how to fly the aircraft.

The FAA said its decision on the 737 Max was made in cooperation with air safety agencies worldwide. Agencies in Europe, Brazil, Canada and China are likely to announce their own approvals separately after independent investigations.

FILE - Ethiopian Red Cross workers carry a body bag with the remains of Ethiopian Airlines Flight ET 302 plane crash victims at the scene of a plane crash, near the town of Bishoftu, southeast of Addis Ababa, Ethiopia March 12, 2019. (REUTERS/Baz Ratner)

Criticism of the FAA and Boeing

The U.S. move follows congressional hearings on the crashes. The hearings led to criticism of FAA officials for weak oversight and having close ties to Boeing. The company was criticized for being in a hurry to set up a software system that put profits over safety. In time, the investigation led to the dismissal of Boeing's chief executive officer.

Investigators studied anti-stall software that Boeing had developed to keep the 737 Max balanced when flying. That software pushed the nose of the aircraft down repeatedly on both of the planes that crashed. In each case, a single sensor caused the problem.

The FAA required Boeing to change the software program so it does not repeatedly point the nose of the plane down. Boeing says the new software does not override, or ignore, the pilot's controls like it did in the past. The company also must add new display systems for pilots and change wiring inside the plane.

The decision on the 737 Max comes in the middle of a health crisis that has frightened away passengers and hurt the aviation industry. Air travel in the United States alone is down about 65 percent from a year ago.

Boeing sales of new planes have dropped because of the 737 Max crisis and the COVID-19 pandemic. Nearly 400 Max jets were in service worldwide when they were grounded. Boeing has built and stored about 450 more since then.

Reuters news agency estimates the company has lost about $20 billion in expected sales.

Reaction to the decision

Massachusetts Institute of Technology Professor John Hansman teaches classes on the science of flight. He noted that people generally avoid airplanes for a few months after there are problems. The Max case is unusual, but Hansman said he would feel safe flying on a Max.

"The whole thing has had more scrutiny than any airplane in the world," he said. "It's probably the safest airplane to be on."

Boeing still faces legal action from families of crash victims.

Families of the Ethiopian crash victims said in a statement that they felt renewed grief after the FAA's decision to return the aircraft to service.

Naoise Ryan's husband was on Ethiopian Airlines Flight 302, which crashed on March 10, 2019. "Our family was broken," she said on Tuesday. "We are suffering and we'll most likely continue to suffer for a very long time, if not for the rest of our lives."

I'm Jonathan Evans.

Reuters news agency reported this story. George Grow adapted the report for VOA Learning English. Mario Ritter, Jr. was the editor.

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Words in This Story

review – n. an examination of something; a report on something

commercial – adj. involving or concerned with business

software – n. the programs and other operating information used by a computer

stall – v. to stop or cause to stop

display – n. an event or performance; something meant to be seen

grief – n. deep sadness

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