Boeing 737 Max to Resume Flying U.S. Passengers on Tuesday

Boeing’s troubled 737 Max plane is expected to carry paying passengers in skies over the United States for the first time in almost two years on Tuesday.

Those passengers will be aboard American Airlines Flight 718, scheduled to leave Miami just after 10:30 a.m. and land in New York at 1:30 p.m., ending a long and difficult chapter for Boeing.

The Max was grounded worldwide in March 2019 after 346 people were killed in a pair of crashes, separated by months, in Indonesia and Ethiopia. The accidents and revelations about the plane’s shortcomings greatly damaged the company’s reputation and cost it tens of billions of dollars in damages, government fines and lost orders.

The Federal Aviation Administration, which has been criticized by lawmakers and safety experts for doing a poor job in certifying the Max in the first place, last month became the first major regulator to lift its grounding order and allow Boeing and the airlines that use the Max to start making the changes necessary to fly the plane again.

The F.A.A. has since been joined by regulators in Brazil. Canadian and European aviation officials are expected to follow with approvals within weeks.

The families of those killed aboard the two fatal flights argue that the Max is still unfit to fly. Last week, they said in a letter to U.S. lawmakers that “the entire recertification process is suspect.” A Senate committee issued a scathing report this month, criticizing Boeing and the F.A.A. for safety and oversight failures.

American plans to use the Max for daily flights between Miami International Airport and La Guardia Airport through Monday. The airline plans to increase service throughout January, using the Max for as many as 36 flights out of Miami each day, according to a letter American executives sent to employees last month. Tuesday’s flight can seat 172 people, 16 in business class and the rest in economy.

United Airlines has said it expects to start using the Max in the first quarter of 2021. Southwest Airlines, a major Boeing client that operates an all-737 fleet, has said it does not expect to fly the plane until the second quarter. Delta Air Lines does not use the plane.

It will be important to public perception of both Boeing and the Max that the first few months of flights be free of any major problems. Last week, Air Canada was forced to divert a Max plane being moved from Marana, Ariz., to Montreal because of engine trouble. The plane landed without incident in Tucson, Ariz., the airline said.