“What do I know about branding?” the president asked in a tweet sent around dawn on Monday. “Maybe nothing (but I did become President!), but if I were Boeing, I would FIX the Boeing 737 MAX, add some additional great features, & REBRAND the plane with a new name. No product has suffered like this one. But again, what the hell do I know?”

Trump knows like the rest of the world that the 737 Max has given Boeing a serious problem.

The US and other countries grounded the 737 Max in mid-March after deadly crashes in Ethiopia and Indonesia. Boeing aims to finish fixing the planes in late April, and any changes would have to be submitted to the Federal Aviation Administration and foreign regulators for approval.

Sunday’s announcement made American the second major carrier to cancel Max flights through the busy summer. Southwest Airlines, the largest operator of Boeing jets, announced last week that it would cancel its Max flights through 5 August. American’s cancellations will last through 19 August.

American had planned to cancel Max flights through early June. By extending cancellations through the summer the airline can plan more reliably for the peak travel season, said Doug Parker, American’s chairman and chief executive, and Robert Isom, president, in a letter to employees.

Airlines are being forced to ground their planes longer than expected after Boeing and the FAA said the company needs more time to complete changes to a flight-control system suspected of playing a role in the crashes.

American’s cancellations represent 1.5% of its total flights each day of the summer. The airline, which has 24 Max jets, said reservations and sales teams will work with customers to manage their travel plans.

American explained on its website that not all flights previously scheduled on a Max would be canceled, because the airline plans to substitute other aircraft for some flights. That also means some flights that were not scheduled to take place on a Max plane may be canceled because the airline aims to affect the smallest number of customers.

American also said on its website that customers can request a full refund if they choose not to be rebooked.

On Twitter, American Airlines passengers posted complaints about canceled flights affecting vacations, speaking engagements and travel to funerals and noted problems rebooking flights.

American canceled 350 out of Dallas-Fort Worth on Saturday, but that had nothing to do with the Max, said a spokesman, Ross Feinstein. The cancellations were caused by hail, thunderstorms and high winds in Dallas followed by snow in Chicago, he said.

“We’re working as hard as possible to rebook customers,” Feinstein said.

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