A Southwest Boeing 737 Max 8 enroute from Tampa prepares to land at Fort Lauderdale-Hollywood International Airport on March 11, 2019 in Fort Lauderdale, Florida, US. (File photo: VCG)

RIO DE JANEIRO, Dec. 9 (Xinhua) -- A Boeing 737 MAX passenger plane restarted commercial flight in Brazil on Wednesday, the first of its kind worldwide after the Boeing plane of this model was grounded for over 20 months due to two deadly crashes, media reports said.

The flight, operated by Brazil's low-cost airline Gol, flew between San Paulo and Porto Alegre, but the airline declined to unveil further details of the inaugural flight.

As Brazil's largest airline with about 36 million passengers annually, Gol said it had full confidence in the safety upgrades and expanded the pilot training program carried out by Boeing as part of aviation regulators' conditions to recertify the plane.

"For the past 20 months, we have been carrying out the most intensive safety review in the history of commercial aviation," Gol's Vice President for Operations Celso Ferrer said in a statement.

Earlier this week, Gol's Chief Executive Officer Paulo Kakinoff said: "The MAX is one of the most efficient aircraft in aviation history and the only one to undergo a complete recertification process."

In March 2019, Gol announced its decision to suspend the use of Boeing 737 MAX 8 model planes until further notice.

The Boeing 737 MAX had been grounded worldwide since March 2019 after crashes in Indonesia and Ethiopia killed all 346 people aboard two flights.

A Boeing 737 MAX aircraft, operated by American Airlines, completed its first public flight earlier this month, with a 45-minute flight from Dallas, Texas, to Tulsa, Oklahoma in the United States.

Last month, the U.S. Federal Aviation Administration rescinded the order that halted commercial operations of the Boeing 737 MAX, paving the way for its return to commercial service.