Europe’s aviation safety regulator kicked off the process of bringing Boeing Co.’s 737 Max back into service, in a major step toward the grounded jet’s global return.

The European Union Aviation Safety Agency published a proposed airworthiness directive Tuesday, laying out changes required before the aircraft can return to service. The move triggers a 28-day public consultation, putting the Max on track for final clearance by early 2021.

EU approval would mark a milestone in Boeing’s effort to return the Max to service outside the U.S., following the Federal Aviation Administration’s granting of final clearance last week. Backing by European regulators would help build global support for the aircraft, after the Max crisis damaged the FAA’s reputation as the leader in air safety.

“I am confident that we have left no stone unturned in our assessment of the aircraft with its changed design approach,” Patrick Ky, EASA’s executive director, said in a statement. “The result was a thorough and comprehensive review of how this plane flies and what it is like for a pilot to fly the Max, giving us the assurance that it is now safe to fly.”

EASA expects to issue the formal ungrounding decision in mid-January, it said in the statement. Ky had previously said in October that he was satisfied with the changes Boeing made to the plane after two crashes within five months killed 346 people, leading to the global grounding of the 737 Max fleet in March 2019.

EU approval is needed for Boeing to begin delivering the Max to customers in the region such as discount carrier Ryanair Holdings Plc. The deliveries will help the U.S. planemaker to unlock about $12 billion in cash that’s tied up in hundreds of jetliners built during the global grounding.

EASA’s airworthiness directive requires nearly the same changes that the FAA has mandated, differing in two areas, the regulator said in a statement. EASA will allow pilots to disable a “stick shaker” warning if it has erroneously been activated, to prevent flight crews from being distracted, and will mandate that the plane’s autopilot system should not be used for certain landings.

Transport Canada indicated last week that it was poised to lift the grounding soon. As long as the flying ban is in place in that country, U.S. airlines can’t operate the upgraded 737 over Canadian air space.

Authorities in Europe, Canada and Brazil worked closely with U.S. regulators to review the technical aspects of the Max, which Stephen Dickson, administrator of the FAA, called the most scrutinized aircraft in history.