A Boeing 737 MAX took off from southern China on Friday, the first domestic flight using the aircraft model since March 2019 when it was grounded after two deadly crashes.
The resumption of flights is a boost for the American manufacturer in one of its most important markets.
China was among the first countries to ground the plane after two fatal accidents involving its flight control software in 2018 and 2019, and was the last major Boeing market to rescind the ban.
On Friday a China Southern Airlines flight left the city of Guangzhou in the afternoon headed for Zhengzhou, tracking website Flightradar24 showed.
A second 737 MAX took off from Guangzhou later in the day, flying to the central city of Wuhan.
Operators had been unable to fly the plane in Chinese airspace since March 2019 when an Ethiopian Airlines flight crashed shortly after takeoff from Addis Ababa, killing 157 people.
That accident came five months after the crash of another 737 MAX in Indonesia, where 189 people died.
Investigators said a major cause of both tragedies was a faulty flight handling system known as the Manoeuvring Characteristics Augmentation System (MCAS).
After modifications were made to the software and pilot training, the aircraft was cleared to fly again in the United States in November 2020, followed by other countries.
Beijing deemed the jet airworthy in December 2021, predicting it would return to Chinese airspace by "the end of the year or early (2022)".
However, the need to clear final hurdles with regulators meant the wait was longer than expected.
Lingering trade tensions with the United States and China's deadliest plane crash for nearly 30 years in 2022 also slowed progress.
But there had recently been signs that carriers would be allowed to resume using the 737 MAX.
MIAT Mongolian Airlines flew one in and out of China on a round trip from Ulaanbaatar to Guangzhou in October, a route which has since been repeated.
Neither China Southern Airlines nor the Chinese civil aviation regulator were immediately contactable for comment regarding Friday's flights.
Boeing's China office declined to comment and referred AFP to aircraft operators.
- Challenge for Boeing -
The ban had affected most airlines operating in the Asia-Pacific region, and presented major challenges for Boeing.
The company said in October it was seeking other potential customers for the 737 MAX because China was still not taking delivery of the jets it had ordered.
In addition, China's zero-tolerance Covid-19 policies had "reduced demand for airplanes in general", Boeing Chief Executive Dave Calhoun said at the time.
In early December, China began the process of reversing years of its zero-Covid policy -- which had included border closures, tight restrictions on movement within the country and lengthy quarantines for travellers.
The loosening has boosted hopes in the travel industry that China might soon open up fully to foreigners.
China is also hoping to challenge the dominance of foreign aircraft models like the 737 MAX with its own domestically produced passenger jet, though most of its parts are sourced from abroad.
The C919 jetliner is expected to make its commercial debut early this year.
The number of known deals for the C919 stands at more than 1,100, based on figures from the state-owned Commercial Aircraft Corp of China (COMAC).
And Boeing has other international rivals too.
China sealed a deal for Airbus jets worth $17 billion last year and the European company began producing its A321 model in the northeastern Chinese city of Tianjin.