(Bloomberg) -- Boeing Co.’s 737 Max is poised to return to commercial service in the U.S. with the first flight since two deadly crashes prompted the longest aircraft grounding in the nation’s history.

American Airlines Group Inc. is scheduled to fly a 737 Max 8 at 10:32 a.m. Tuesday on a round trip from Miami to New York’s LaGuardia Airport. American’s president, Robert Isom, plans to be on both flights. U.S. regulators lifted the flying ban last month after ordering extensive revisions to the plane’s flight-control computer and other changes.

For Boeing, the Max’s return is the keystone of the company’s efforts to restore a balance sheet battered by the grounding and the coronavirus pandemic. The Max accounts for about 80% of Boeing’s backlog of aircraft orders and represents the company’s only offering in the crucial single-aisle market, in which the U.S. planemaker trails Airbus SE.

American said it hasn’t seen signs that customers are trying to avoid the Max.

“Bookings on the Max are comparable to other aircraft, and we aren’t seeing data to suggest customers don’t want to fly the aircraft,” Sarah Jantz, a spokeswoman for the Fort Worth, Texas-based carrier, said in an email.

The aircraft returned to commercial service earlier this month when Brazil’s Gol Linhas Aereas Inteligentes SA began operating regular domestic flights with the Max. Last week, a Max flown by Air Canada on a test flight experienced engine issues that forced the crew to make an emergency landing in Tucson, Arizona, Aviation24.be reported.

Southwest Airlines Co., the Max’s largest customer, plans to fly the model next year, as do United Airlines Holdings Inc. and Alaska Air Group Inc.

The Max was grounded in March 2019. A total of 346 people died in the two crashes.

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