The United States is the last country to allow flights of the Boeing 737 MAX fleet after at least 47 countries and multiple airlines grounded the aircraft following Sunday's Ethiopian Airlines crash.

At least 271 of the 371 MAX planes in service were grounded, according to CNN calculations. To date, 385 MAX aircraft have been delivered, according to Flight Global, of which 344 are the MAX 8 variant.

On Wednesday, Canada joined Egypt, Hong Kong, Lebanon and New Zealand in banning all Boeing MAX aircraft from their airspace as an extra safety precaution, joining scores of nations, carriers and authorities that have temporarily suspended the MAX 8 model or other models in the range. On Tuesday, the European Union announced that all flights into, within or out of the EU on the Boeing Max aircraft would be banned.

On Wednesday afternoon, Canada's Minister of Transport Marc Garneau said that as the result of new data that they received in the morning, they will no longer allow the Boeing 737 MAX 8 or 9 aircraft to take off or land in Canada, nor will they allow aircraft to fly over Canadian airspace.

Six minutes after take-off, Ethiopian Airlines Flight 302 plummeted into a field, killing all 157 people on board. Shortly after leaving Addis Ababa's Bole International Airport, the pilot reported flight control problems and asked to return to the base.

As investigators search for clues into the cause of the disaster, some aviation experts are drawing parallels to the Lion Air Boeing MAX 8 plane that went down last October over the Java Sea in Indonesia, killing all 189 people on board.

Both Boeing and the US Federal Aviation Administration (FAA) have said they have no plans to ground the aircraft.