The Federal Aviation Administration has cleared the Boeing 737 Max to fly for the first time since the plane was involved in two deadly crashes within five months of each other. On Wednesday, FAA Administrator Steve Dickson signed an order that paves the way for the troubled aircraft to return to commercial service.

The Boeing 737 Max has been grounded since March 2019 following two fatal crashes that killed a total of 346 passengers and crew members. Boeing continued to manufacture the airplane, but in December 2019, the company announced plans to halt production at its Renton, Washington manufacturing plant. Production resumed in May 2020 but at a much lower rate and with a renewed focus on workplace safety and quality.

The FAA says its safety staff has “worked diligently to identify and address the safety issues” that contributed to the crash of Lion Air Flight 610 on October 29th, 2018, followed by the crash of Ethiopian Airlines Flight 302 on March 10th, 2019. President Donald Trump approved the grounding of the jet three days later, after nearly 40 countries had done the same.

“The path that led us to this point was long and grueling,” Dickson said in a video message. “But we said from the start that we would take the time necessary to get this right.”

One of the particular issues that doomed both flights was a piece of software known as the Maneuvering Characteristics Augmentation System, or MCAS, that was designed to stop the plane from stalling in very specific takeoff situations. Using information from sensors on the outside of the plane, MCAS was able to pitch the nose of the plane down if it believed it was angled too high.

A major problem with MCAS was that, in a bid to skirt the lengthy and costly process of retraining pilots on this new piece of software, Boeing simply hid it from them and from the FAA. Another was that MCAS only pulled data from one external sensor, meaning it could be led astray if that sensor was damaged. All of this led to the pilots on both fatal flights scrambling to try to fix a problem they didn’t understand in their final moments.

As part of its lengthy review process, the FAA required Boeing to install new software for the plane’s flight control computer and displays, revise its manual and enhance its training for flight crew, and implement new maintenance procedures. 

Dickson said he flew the 737 Max himself for two hours in September to personally evaluate the changes the company made to the flight control software. “During the past 20 months, and my personal experience flying the aircraft, I can tell you now that I am 100 percent comfortable with my family flying on it this morning,” he said.

The Boeing 737 Max returns to service at an uncertain time for the airline industry. The coronavirus crisis has brought the industry to the edge of financial ruin, with all the major airlines experiencing historic losses. Collectively, the Big Three — United, Delta, and American — lost a staggering $10 billion during the second quarter of 2020. JetBlue lost $320 million, Southwest $915 million, and budget carriers Spirit and Alaska lost $144 million and $214 million, respectively.

Airports are described as “ghost towns.” On November 17th, the Transportation Security Administration recorded 611,497 air travelers, down from 1,900,895 passengers on the same day in 2019.

Boeing has been hit hard as well. The Chicago-based airplane manufacturer — the biggest exporter in the US — laid off 7,000 workers in October, after already reducing its workforce by 19,000 employees earlier this year.

The end of the nearly two-year ban means Boeing can begin delivering its backlog of around 3,000 737 Max jets to its customers. But the fatal crashes and subsequent investigations forced the company to reevaluate its safety culture. Former CEO Dennis Muilenburg was forced out in December 2019, less than a year after the crash of Lion Air 610.

Muilenburg spent much of 2019 trying to reassure the public of the 737 Max’s safety, while promising shareholders and industry partners that the plane would be back in the air by the end of the year — causing US airlines like Southwest, American, and United to repeatedly revise their predictions for when they’d be able to reintroduce the 737 Max to their respective fleets.

“We will never forget the lives lost in the two tragic accidents that led to the decision to suspend operations,” said Muilenburg’s replacement, David Calhoun, in a statement. “These events and the lessons we have learned as a result have reshaped our company and further focused our attention on our core values of safety, quality and integrity.”