The Civil Aviation Authority of Thailand (CAAT) is planning to enforce a new rule requiring passengers on Thai-owned chartered flights or special flights transitioning through Thailand to have a valid Covid-19 clearance certificate.
The requirement will apply even for flights that make a refuelling stop in Thailand without passengers leaving the aircraft, said CAAT director-general Chula Sukmanop.
He said the new rule is intended to prevent Thai airlines from being blacklisted by authorities in destination countries in case a Covid-19 infection is discovered on their flights.
Mr Chula said that the clearance certificate must be produced before customers buy their tickets.
He cited two incidents in which chartered flights to China operated by Thai-registered carriers were facing a temporary ban -- imposed by the Civil Aviation Administration of China (CAAC) -- upon the discovery of passengers infected with Covid-19.
The flights were operated by Thai AirAsia X and Thai Lion Air. The AirAsia flight had originated in Malaysia and was bound for the city of Tianjin; however, it had made stops in Manila and Thailand along the way.
Meanwhile, the Thai Lion Air flight took off from Jakarta for Guangzhou and had made a stop at Don Mueang airport.
At each destination airport, passengers of both flights went through health checks, which is when some tested positive for Covid-19.
After the positive cases were discovered, it was reported that China banned both airlines for a week.
The passengers found to be infected were on Thai Lion Air SL117 to Guangzhou on July 7 and Thai AirAsia X XJ808 to Tianjin on July 10.
Taweesilp Visanuyothin, spokesman of the Centre for Covid-19 Situation Administration, said both chartered flights had made stopovers in Thailand, probably to enable them to fly to China since direct routes from Kuala Lumpur and Jakarta are still banned.
He confirmed that passengers on both flights remained on their planes during the stopovers. About five or six passengers on both flights tested positive for Covid-19, he added.
Mr Chula said the Chinese authorities have enforced regulations banning airlines for seven days in the event a flight is found carrying 10 or fewer passengers infected with Covid-19.