What happens to customers on cancelled Max 8 flights?

Graphic How the MCAS system works

The United States grounded Boeing Co's money-spinning 737 MAX aircraft on Wednesday over safety fears after an Ethiopian Airlines plane crash that killed 157 people, leaving the world's largest planemaker facing its worst crisis in years.

"The safety of the American people, of all people, is our paramount concern", Mr Trump said.

He said even though their travel arrangements are now in disarray, they had already made up their mind not to fly on that plane.

The move is a major blow to Boeing, which has lost billions of dollars in value this week as nation after nation announced they were barring the aircraft from flying.

Lawmakers have also called for the planes to be grounded.

By banning Max 8 and 9 models of the aircraft from flying in the U.S., the FAA has thrown a major logistical challenge at American and Southwest Airlines, which are the two biggest users of the plane.

The U.S. Federal Aviation Administration (FAA) cited new satellite data and evidence from the scene of Sunday's crash near Addis Ababa for its decision to ground the planes.

The Senate Commerce Committee also plans to hold a hearing as early as April.

The time line is to cater to situations where aircraft can be positioned at maintenance facilities and global flights can reach their destinations, the DGCA said.

Boeing responded to the FAA's decision in a statement just after Trump's announcement, saying it still has "full confidence" in its aircraft.

"We are doing everything we can to understand the cause of the accidents in partnership with the investigators, deploy safety enhancements and help ensure this does not happen again", Boeing president and chief executive Dennis Muilenburg said.

The U.S. action followed Canada's decision to halt Max flights earlier Wednesday.

This required airlines to instruct pilots on applying the checklist if they have difficulty controlling an aircraft that's being pushed into a nose-down position by the autopilot.

Other routes, notably Halifax-London and St. John's-London are cancelled in the short term, she said, with passengers re-routed through Montreal and Toronto.

The FAA had previously held out while many countries banned the aircraft.

The crashes prompted numerous airlines and countries to announce this week they were grounding the gets pending investigation into the cause.

Until then, "all of those planes are grounded effective immediately", Mr Trump said. The company had 31 737 MAX 8 planes in its fleet at the end of 2018, and it's expecting to add another 37 MAX 8 jets this year. The data showed similarities between the Ethiopian Airlines flight that crashed and killed 157 people and the Lion Air crash that killed 189 people in Indonesia in October.

"It's a awful, bad thing".

"We have been in contact with Boeing and will continue to stay close to the investigation as it progresses", Southwest said in a statement to Business Insider.

The grounding was welcomed by American air workers, and the announcement came hours after the US Association of Professional Flight Attendants (APFA) called on the US to ground the planes in question. In contrast, its fleet includes more than 500 of the older 737-700 model. The others are GOL (Brazil), WestJet (Canada), Air Canada and United.

A significant impact will be felt in Miami, where American has concentrated its initial Max deliveries for service to the Caribbean and to New York's LaGuardia airport.