During a test flight between Montreal and Arizona, an Air Canada Boeing 737-8 Max suffered an engine issue which prompted the pilots to make an emergency landing, aviation websites and the Reuters news agency reported on Friday.

Regulators across the world previously banned the plane due to its involvement in two deadly crashed in the past three years. The 20-month flight ban imposed by US authorities was only lifted last month.

The pilots testing the plane on Tuesday received an "engine indication" shortly after takeoff and "decided to shut down one engine," an Air Canada spokesman said an emailed statement to Reuters.

"The aircraft then diverted to Tucson, where it landed normally and remains," the statement said. The incident took place earlier this week.

Belgian aviation news website Aviation24.be reported that the crew received a left engine hydraulic low pressure indication and declared a PAN PAN emergency — which signals there is an urgent problem but no immediate danger — before diverting the flight.

Major aviation disasters

The Boeing 737 Max was given the approval to resume US domestic flights late in December after software upgrades and additional pilot training. It is already back in service in Brazil.

Canada has yet to approve the revamped plane for passenger flights but has permitted test flights.

The two fatal crashes occurred in October 2018, when a Lion Air 737 Max nosedived into the sea off Indonesia, killing all 189 passengers and crew on board, and in Ethiopia in March 2019, when an Ethiopian Airlines flight came down southeast of the capital, Addis Adaba, killing all 157 people aboard. Both crashes happened shortly after takeoff.

Canada was one of the last countries to ground the model after the second crash.