South Korea has granted Thai AirAsia X (TAAX) the right to start a second Bangkok-Incheon daily flight, due to start on Oct 25.
The surprise move by the Ministry of Land, Infrastructure and Transport (MOLIT) is seen as Seoul's easing of restrictions on new flights operated by Thai-registered carriers to its airports.
South Korea began to curb extra flights by Thai-registered airlines in late March shortly after the International Civil Aviation Organization (ICAO) expressed "significant safety concerns" or SSCs over Thai aviation.
But Seoul has not made the ban as explicit as Japan, which issued an official ban on flights by Thai carriers beyond those allowed ahead of the ICAO's issuance of a yellow card on the shortcomings found by an audit of Thailand's Department of Civil Aviation (DCA) in January.
China is the only other country that has subjected Thai-registered airlines to flight restrictions in pursuance of the ICAO notification.
TAAX chief executive Nadda Buranasiri yesterday confirmed that Thailand's first long-haul low-cost carrier has officially secured the right to add another scheduled daily flight to Incheon both from the MOLIT and the DCA.
Industry executives said the permission granted to TAAX reflected South Korea's selective approach to Thai aviation safety oversight troubles rather than the blanket approach of Japan.
"The Koreans must have kept track of TAAX's operational and safety performance over the period since the ICAO issued SSCs before agreeing to give the right to add a second daily service," said an executive who asked not to be named.
"The decision may also stem from Seoul's desire to revive some of the inbound air passenger traffic lost during the outbreak of Middle East respiratory syndrome (Mers) in the country," the executive added.
Mr Nadda pointed out that TAAX's decision to launch a second daily Bangkok-Incheon service is a response to stronger demand on the route.
The Mers outbreak in South Korea in the past two months had a limited short-term effect on traffic demand on the route but it has recovered as the spread of the deadly virus has been contained, he said.
"There is great potential for this route to continually grow," Mr Nadda added.
Since the inaugural flight to Incheon in June last year, the airline has recorded an average load factor of 83%.
In the first five months of this year, 201,480 Thais travelled to South Korea, an increase of 1.4% over the same period last year, while 550,699 Koreans visited Thailand, up by 18.8%.
TAAX yesterday begun accepting bookings for the second daily flight, which takes off from Don Mueang airport at 8.05am, with the return flight departing Incheon at 4.25pm.
Last month, TAAX decided to terminate its daily Bangkok-Sapporo flight on Aug 1, just three months after its launch, which was only made possible by utilising its sister Malaysia-based AirAsia X's aircraft to circumvent Japan's restrictions.