By CBS 2 Chicago Staff

(CBS/CNN) — Nearly two years after being grounded over two deadly crashes, Boeing’s 737 Max jets have been cleared to carry passengers again, after the Federal Aviation Administration cleared design changes that will make the planes safe to return to the skies.

FAA Administrator Steve Dickson has signed an order rescinding the grounding. He said last week the agency was in the final stages of reviewing design changes to the Max that would make it safe to fly again. “I will lift the grounding order only after our safety experts are satisfied that the aircraft meets certification standards,” he said in a statement at the time.

The FAA will let Boeing resume delivery of newly produced 737 Max aircraft, which will have the design changes in place. But the agency itself will issue the Airworthiness Certificate for each aircraft. Boeing used to do that.

“The FAA’s directive is an important milestone,” said Stan Deal, CEO of Boeing Commercial Airplanes, in a statement. “We will continue to work with regulators around the world and our customers to return the airplane back into service worldwide.”

The design changes and new pilot training requirements will be spelled out in an Airworthiness Directive that will be issued Wednesday and go into effect when it appears in the federal register, reports CBS News correspondent Kris Van Cleave.

The green light also follows numerous congressional hearings on the crashes that led to criticism of the FAA for lax oversight and Boeing for rushing to implement a new software system that put profits over safety and ultimately led to the firing of its CEO.

The Air Line Pilots Association expressed confidence that the 737 MAX is safe.

“Based on the Airworthiness Directive, ALPA believes that the engineering fixes to the flight-critical aircraft systems are sound and will be an effective component that leads to the safe return to service of the 737 MAX,” the union said in a statement on Wednesday.

The plane, the best-selling jet in Boeing’s fleet, was grounded in March 2019 after two fatal crashes that killed 346 people. It was discovered that a safety feature meant to stop the plane from climbing too fast and stalling had improperly forced the nose of the plane down, causing the crashes.

The process of approving the plane to carry passengers has stretched on far longer than originally expected and cost Boeing more than $20 billion, according to the company. Lost orders for the jet during that time could make it among the most expensive mistakes ever made by a company.

Although approval was expected this week, Boeing shares nonetheless rose 6% in premarket trading Wednesday.

The first step

The FAA action is only the first step in allowing 59 airlines which own the 387 grounded planes to fly them as part of their schedule. The FAA said in a statement before any of the planes can be flown with passengers again, the necessary changes to the 737 Max identified in the approval process must be installed, the FAA must inspect the individual planes. The pilots must also complete additional training.

That process is expected to take between a few weeks and a few months, depending on the airline. So far only American Airlines has added the plane to its schedule for a handful of flights between Miami and New York in late December and early January. Other airlines are holding off. Southwest, which has 34 of the jets — more than any other airline — isn’t expected to fly passengers on the 737 Max until spring of 2021.

Family members of victims speak out

Some of the family members of those who died in the crashes have objected to the return to service for the plane. They say Boeing made mistakes in the design of the 737 Max, the newest version of a long-serving plane, which made their version dangerous, and the FAA made mistakes approving the original version and recertifying it to fly now.

“The plane is inherently unstable and it is unairworthy without its software,” said Michael Stumo, whose daughter Samaya Rose Stumo died in the March 2019 crash of an Ethiopian Airlines plane. “They haven’t fixed it so far. The flying public should avoid the Max in the future. Change your flight.”

Stumo and other family members had a press conference Tuesday ahead of the announcement. Stumo said the FAA should have insisted on a third sensor be added to determine if the plane is in danger of stalling. He said other changes should have been made to the way pilots are alerted if there is a problem.

“We as family members want to avoid a third crash,” he said.

The investigation into how to fix the plane was originally expected to be finished by the fall of 2019, but stretched on as new questions about the plane arose.

FAA and Boeing praise the process

“The path that led us to this point was long and grueling,” said FAA Administrator Steve Dickson in a video statement Wednesday. “But we said from the start that we would take the time necessary to get this right. We were never driven by a timeline, but rather following a methodical and deliberate safety process. During this time FAA employees diligently worked on the fixes that were necessary.”

As part of the review process Dickson flew the plane himself in September, and went through the training pilots will have to complete.

“Base on all the activities we have undertaken during the past 20 months, and my personal experience flying the aircraft, I can tell you now I am 100% comfortable with my family flying on it,” he said.

The FAA has worked throughout the process with aviation authorities around the world, and most are expected to issue their own orders to unground the plane as well. But there could be delays in returning the planes to service around the world. Most of the 387 grounded planes are outside of the United States.

Boeing also said it is confident that the plane will be safe to fly once all the required steps are taken.

“We will never forget the lives lost in the two tragic accidents that led to the decision to suspend operations,” said David Calhoun, chief executive officer of The Boeing Company. “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.”

Problems throughout the inspection

In addition to coming up with a software update to the faulty safety system, problems with the safety of the plane’s wiring were discovered. There were also questions about the lack of training for pilots who were moving from the original 737 to the 737 Max, which had been a selling point for the plane.

The investigation also revealed that many Boeing employees were privately expressing doubts about the planes during the original approval process.

“Would you put your family on a Max simulator trained aircraft? I wouldn’t,” wrote one employee to another during the process in an internal communication revealed during the process. Another employee described the plane as “designed by clowns, who in turn are supervised by monkeys.” And another comment added: “piss poor design.”

— CNN’s Pete Muntean and Gregory Wallace contributed to this report

(© Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. CBS News and the CNN Wire contributed to this report.)

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