Two Air Canada Boeing 737 MAX 8 aircrafts are seen on the ground as Air Canada Embraer aircraft flies in the background at Toronto Pearson International Airport in Toronto, Ontario, Canada, March 13, 2019.

Image used for illustrative purpose. A seal is seen on Garuda Indonesia's Boeing 737 Max 8 airplane parked at the Garuda Maintenance Facility AeroAsia, at Soekarno-Hatta International airport near Jakarta, Indonesia, March 13, 2019.

Grounded Boeing 737 Max 8 passenger plane of the Norwegian low-cost airline Norwegian is seen parked on the tarmac at Helsinki Airport in Vantaa, Finland March 13, 2019. Lehtikuva/Heikki Saukkomaa via REUTERS

An Air Canada Boeing 737 MAX 8 from San Francisco approaches for landing at Toronto Pearson International Airport over a parked Air Canada Boeing 737 MAX 8 aircraft in Toronto, Ontario, Canada, March 13, 2019.

A Southwest Airlines Co. Boeing 737 MAX 8 aircraft sits at Midway International Airport in Chicago, Illinois, U.S., March 13, 2019.

Garuda Indonesia's Boeing 737 Max 8 airplane is seen as it parked at the Garuda Maintenance Facility AeroAsia, at Soekarno-Hatta International airport near Jakarta, Indonesia, March 13, 2019.

A Jet Airways Boeing 737 MAX 8 aircarft is seen parked inside a hanger during its induction ceremony at the Chhatrapati Shivaji International airport in Mumbai, India, June 28, 2018. Picture taken June 28, 2018. Image for illustrative purposes.

A Jet Airways Boeing 737 MAX 8 aircraft is seen parked inside a hanger during its induction ceremony at the Chhatrapati Shivaji International airport in Mumbai, India, June 28, 2018. Picture taken June 28, 2018. Image used for illustrative purposes

Workers attend a ceremony marking the 1st delivery of a Boeing 737 Max 8 airplane to Air China at the Boeing Zhoushan completion center in Zhoushan, Zhejiang province, China, December 15, 2018.

Grounded Boeing 737 Max 8 passenger plane of the Norwegian low-cost airline Norwegian is seen parked on the tarmac at Helsinki Airport in Vantaa, Finland March 13, 2019. Lehtikuva/Heikki Saukkomaa via REUTERS

SilkAir's new aircraft, the Boeing 737 Max 8, sits on the tarmac at Changi Airport in Singapore October 4, 2017.

An American Airlines Boeing 737 MAX 8 flight from Los Angeles lands at Reagan National Airport shortly after an announcement was made by the FAA that the planes were being grounded by the United States in Washington, U.S. March 13, 2019.Image used for illustrative purpose.

Southwest Airlines Co. Boeing 737 MAX 8 aircraft sit next to the maintenance area after landing at Midway International Airport in Chicago, Illinois, U.S., March 13, 2019.

Image used for illustrative purpose. An American Airlines Boeing 737 MAX 8 flight from Los Angeles approaches for landing at Reagan National Airport shortly after an announcement was made by the FAA that the planes were being grounded by the United States in Washington, U.S. March 13, 2019.

An Aerolineas Argentinas Boeing 737 MAX 8 is seen on the tarmac of Ezeiza Airport, on the outskirts of Buenos Aires, Argentina December 4, 2017.

A SilkAir Boeing 737 Max 8 plane (behind) sits on the tarmac near a hangar after suspended operations for all Boeing 737 Max 8 planes, at Changi Airport in Singapore, March 12, 2018.

A Boeing 737 MAX 8 aircraft bearing the logo of China Southern Airlines is parked at a Boeing production facility in Renton, Washington, U.S., March 11, 2019.