Indonesia has ratcheted up the pressure on Thailand by freezing the number of flights and the types of aircraft Thai-based carriers can use on flights between the countries.

The Bangkok Post says the Indonesian Ministry of Transportation instigated the move in late May, shortly before the International Civil Aviation Authority (ICAO) formally instated a Serious Safety Concern (SSC) against Thailand.

As with other countries such as Australia, China, Cambodia, Japan, South Korea, and Singapore, Indonesia has also begun subjecting Thai charter operators to additional safety and maintenance checks when their aircraft are in country.

According to the ch-aviation aircraft database, while no Thai charter operators currently serve Indonesia, Thai AirAsia (FD, Bangkok Don Mueang), Jet Asia Airways (Bangkok Suvarnabhumi), and Thai Airways International (TG, Bangkok Suvarnabhumi) do offer scheduled services between the two countries.

Thailand's aviation industry has been reeling since news first came out in March that its Department of Civil Aviation (DCA) had failed a January Universal Safety Oversight Audit Programme (USOAP) inspection.

Sources in Bangkok inform ch-aviation that the DCA, in a bid to amend shortcomings in its issuance of Air Operator Certificates (AOC) and Air Service Licences (ASL), has begun subjecting applications to additional scrutiny in line with ICAO requirements. As a result, some start-ups have been forced to defer their launch plans amid more thorough and rigorous testing.

Last week, the US Federal Aviation Administration (FAA) undertook its own audit of Thailand's aviation environment the results of which are due to be published towards the end of September.