It said the ban was a "precautionary measure" and that the GCAA would monitor and reassess the situation as more information on the latest incident was obtained.
Boeing will be permitted to finish manufacturing any 737 MAX now in production, but will not be allowed to use them.
Sunday's plane crash was the second in five months involving a Boeing 737 Max 8 aircraft. They are working very, very hard right now. The order to ground the planes comes as other nations grounded the aircraft type, and under increasing pressure for the U.S.to follow suit.
Jeff Hoppenstein and Eric Speer who fly frequently for their company, Club Systems, say their travel plans from Greenville to Texas aren't impacted by the grounding Wednesday but they worry what the long term effects could be. But the United States regulator says it is safe to fly.
He said pilots and airlines have been notified, adding that the safety of the American people is of "paramount concern".
"Any plane now in the air will go to its destination and will thereafter be grounded until further notice", said President Trump.
We sincerely thank all stakeholders for the continued confidence placed in the National Airline of Trinidad and Tobago.
We talked to passengers headed to Ireland, Spain, and Toronto.
"At the moment we're putting our focus on operations today and assisting airlines as they try to swap aircraft and potentially move them around to different gates", said Reid Fiest, from the Calgary Airport Authority.
At Orlando International Airport, a Southwest Airlines flight arriving in Orlando from Nashville was canceled Thursday, as well as the same plane subsequently leaving for Denver.