FILE - An aerial photo shows several Boeing 737 MAX airplanes grounded at Boeing Field in Seattle, Washington, March 21, 2019.
FILE - An aerial photo shows several Boeing 737 MAX airplanes grounded at Boeing Field in Seattle, Washington, March 21, 2019.

In a potential challenge to U.S.-led efforts to build consensus on the Boeing Co 737 MAX flying again, Canada and Europe said on Wednesday they would bring back the grounded aircraft on their own terms if their specific concerns are not addressed.

Global regulators will meet in Fort Worth, Texas, on Thursday where the U.S. Federal Aviation Administration hopes to reach an international consensus on how to move forward with the MAX, U.S. officials told Reuters.

The plane was grounded worldwide in March following a fatal Ethiopian Airlines crash just months after a similar Lion Air disaster in Indonesia which together killed 346 people.

Global airlines that had rushed to buy the fuel-efficient, longer-range aircraft have since canceled flights and scrambled to cover routes that were previously flown by the MAX.

File-This Nov. 30, 2000 file photo shows mission s
File-This Nov. 30, 2000 file photo shows mission specialist Marc Garneau of Canada waving to photographers as he leaves the Operations and Checkout Building.

"From our point of view, if we all work together and we all reach the same aim, fine. If we don't, we'll choose our own time to decide when the planes are safe to fly again," Canadian Transport Minister Marc Garneau told Reuters in an interview.

"The number one focus for us is that we in Canada must be satisfied. It doesn't matter what others do. So if we are not perfectly synchronized with certain other countries that's how it going to be," Garneau said.

Regulators are expected to discuss Boeing's proposed software fix and new pilot training that are both key to re-starting flights. Boeing has not yet formally submitted its proposals to the FAA.

A spokesman for the European Aviation Safety Agency said on Wednesday that it would complete an additional independent design review of the plane once the FAA approves Boeing's proposed changes and establishes "adequate training of Boeing MAX flight crews."

Foreign regulators have already signaled disagreements over measures to end the grounding, with Garneau calling in April for pilots to receive simulator training for the MAX, rather than computer courses, going a step beyond FAA-backed proposals.

Daniel Elwell, acting administrator of the Federal Aviation Administration, testifies during a House Transportation Committee hearing on Capitol Hill in Washington, May 15, 2019, on the status of the Boeing 737 MAX aircraft.
Acting FAA Chief Defends Agency's Safety Certification Process     

The acting head of the Federal Aviation Administration defended the way his agency certifies airline safety after two deadly crashes of the now-grounded Boeing 737 Max jet.

Daniel Elwell called the system in which FAA-approved employees at plane manufacturers inspect the aircraft they built themselves “a good system.”

But skeptical Democrats on the House Transportation Committee questioned the agency’s credibility.

They told Elwell that the closeness between Boeing and the FAA may be one of the reasons it took the agency a relatively long time to ground the Boeing jets.

“The public perception

Acting FAA Administrator Dan Elwell told Congress last week the FAA is working closely with other civil aviation authorities "to address specific concerns related to the 737 MAX."

United Airlines Chief Executive Oscar Munoz said on Wednesday that FAA approval is only the first step, with public and employee confidence key to deciding when to fly its 14 MAX jets again.