By GIO BENITEZ, SAM SWEENEY, and MINA KAJI, ABC News

(DALLAS) — The Boeing 737 MAX returned to the skies for the first time Wednesday with members of the general public onboard since two fatal crashes forced U.S. regulators to ground the plane in March 2019.

American Airlines flew journalists on a demo flight from Dallas to Tulsa, Oklahoma, in an effort to reassure passengers that the upgraded MAX is safe. Since the crashes, Boeing rewrote the entire MAX flight computer software, receiving the Federal Aviation Administration’s approval for the jet to reenter commercial service on Nov. 18.

Airlines are now tasked with training their pilots — a process that could take months. But arguably the biggest challenge will be winning the public’s trust.

American is the only U.S. airline that has plans to resume MAX flights in 2020. The carrier will soon welcome its own employees on board the MAX for more demo flights in preparation for American’s first flight with paying passengers on Dec. 29 from Miami to New York City. United Airlines and Southwest Airlines don’t plan to fly the MAX until later in 2021.

American said customers will know whether they are booking a flight on a MAX aircraft.

“I know our pilots would not get in this aircraft if they didn’t think it was safe,” American Chief Operating Officer Robert Isom told ABC News.

Relatives who lost loved ones in the crashes called the demo flight a publicity stunt — many of them urging passengers to avoid boarding a MAX in the future.

“Neither of us would ever get on a 737 MAX,” Nadia Milleron, who lost her daughter Samya in the Ethiopia crash, said. “And we will warn every single person we know and make sure they don’t fly on a 737 MAX.”

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