The Federal Aviation Administration on Wednesday cleared Boeing\u0027s 737 Max to fly again, CBS News correspondent Kris Van Cleave reports. The approval comes after the jets were grounded for 20 months due to a pair of crashes that killed 346 people.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 return to the skies. "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\u0027s 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, Van Cleave says.The green light also follow\u00a0numerous 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.Focus on anti-stall techRegulators around the world grounded the Max in March 2019, after the crash of an Ethiopian Airlines jet. That happened less than five months after another Max, flown by Indonesia\u0027s Lion Air, plunged into the Java Sea. All passengers and crew members on both planes were killed. Investigators focused on anti-stall software that Boeing had devised to counter the plane\u0027s tendency to tilt nose-up because of the size and placement of the engines. That software pushed the nose down repeatedly on both planes that crashed, overcoming the pilots\u0027 struggles to regain control. In each case, a single faulty sensor triggered the nose-down pitch. Boeing\u0027s redemption comes in the middle of a pandemic that has scared away passengers and decimated the aviation industry, limiting the company\u0027s ability to make a comeback. Air travel in the U.S. alone is down about 65% from a year ago.Boeing sales of new planes have plunged because of the Max crisis and the coronavirus pandemic. Orders for more than 1,000 Max jets have been canceled or removed from Boeing\u0027s backlog this year. Each plane carries a sticker price between $99 million and $135 million, although airlines routinely pay far less than list price.John Hansman, an aeronautics professor at MIT, said people typically avoid airplanes for a few months after there are problems. But the Max case is unusual, and were it not for the novel coronavirus, Hansman said he would feel safe flying on a Max. "This whole thing has had more scrutiny than any airplane in the world," he said. "It\u0027s probably the safest airplane to be on." American is the only U.S. airline to put the Max back in its schedule so far, starting with one round trip daily between New York and Miami beginning Dec. 29. Nearly 400 Max jets were in service worldwide when they were grounded, and Boeing has built and stored about 450 more since then. All have to undergo maintenance and get some modifications before they can fly.Pilots must also undergo simulator training, which wasn\u0027t required when the aircraft was introduced. Hansman said pilot training for qualified 737 pilots shouldn\u0027t take long because Boeing has fixed problems with the Max\u0027s software. It no longer automatically points the plane\u0027s nose down repeatedly, and doesn\u0027t override commands from the pilot, according to Boeing. The company posted a summary of changes to the plane."Change your flight"Relatives of people who died in the crashes remain unconvinced of the Max\u0027s safety. They accuse Boeing of hiding critical design features from the FAA and say the company tried to fix the tendency for the plane\u0027s nose to tip up with software that was implicated in both crashes.\u00a0"The flying public should avoid the Max," said Michael Stumo, whose 24-year-old daughter died in the second crash. "Change your flight. This is still a more dangerous aircraft than other modern planes."Boeing\u0027s reputation has taken a beating since the crashes. Its then-CEO, Dennis Muilenburg, initially suggested that the foreign pilots were to blame. However, congressional investigators discovered an FAA analysis - conducted after the first Max crash - predicted there would be 15 more crashes during the plane\u0027s life span\u00a0 if the flight-control software wasn\u0027t fixed. After an 18-month investigation,\u00a0 the House Transportation Committee heaped blame on Boeing, which was under pressure to develop the Max to compete with a plane from European rival Airbus, and the FAA, which certified the Max and was the last agency in the world to ground it after the crashes. The investigators said Boeing suffered from a "culture of concealment" and pressured engineers in a rush to get the plane on the market. Boeing was repeatedly wrong about how quickly it could fix the plane. When those predictions continued to be wrong, and Boeing was perceived as putting undue pressure on the FAA, Muilenburg was fired in December 2019. Dickson \u00e2\u0080\u0094 who flew F-15 fighters in the Air Force before serving as a pilot and an executive at Delta Air Lines \u00e2\u0080\u0094 foreshadowed the agency\u0027s decision to clear the Max to fly again with comments in September, after he climbed into the cockpit of a Max for a two-hour test flight. "I liked what I saw on the flight," Dickson declared that day.Some relatives of passengers who died in the Ethiopian crash dismissed Dickson\u0027s flight as a stunt to benefit Boeing. In recent weeks, European regulators also signaled their likely approval of Boeing\u0027s work. Regulators in Canada and China are still conducting their own reviews.Relatives say it\u0027s too soon, and they and their lawyers say Boeing and the FAA are withholding documents. Naoise Ryan, an Irish citizen whose husband died in the Ethiopian crash, said the Max is "the same airplane that crashed not once but twice because safety was not a priority for this company."