A renewed, muscular Civil Aviation Authority of Thailand (CAAT) has sanctioned Asian Air (Thailand) (Bangkok Don Mueang), City Airways (Bangkok Suvarnabhumi) and tightened existing measures taken against Business Air (Thailand) (Bangkok Suvarnabhumi) for violating the country's civil aviation regulations.

The Bangkok Post reports that last week, the CAAT grounded Asian Air after the Central Bankruptcy Court in Bangkok ordered the airline's assets frozen at the behest of an undisclosed creditor, said to be an MRO firm owed outstanding dues. The full-service airline said it was exploring all avenues to 'resume its operations as soon as possible' with co-founder David Srichai-udom stating that it had recently reduced outstanding debt from THB100 million (USD2.81 million)to THB10 million (USD280,800).

Concerning City Airways, the CAAT said continued doubts about the airline's safety culture had forced it to ground its only active aircraft - B737-400 HS-GTG (msn 27191) - ahead of Sunday's flight to Hong Kong International. City Airways may resume operations once the CAAT's concerns have been fully addressed, the watchdog said.

Concerning Business Air, the CAAT has revoked the registration of the carrier's only aircraft - B767-300(ER) HS-BID (msn 24848) - two weeks after a Thai court allowed it to resume operations.

The airline, also known as Intira Airlines (Bangkok Suvarnabhumi), was grounded in mid-January on account of its THB1 billion (USD28.08 million) in unpaid debts owed to air traffic control and aeronautical communication services provider, Aeronautical Radio of Thailand (Aerothai).

In addition to auditing Business Air's books, the CAAT has also given it thirty days to source another aircraft and resume operations or risk losing its AOC altogether.

Established last month, the CAAT is the Thai government's response to an embarrassing 2015 which saw the ICAO institute Significant Safety Concerns (SSC) against Thailand and the US Federal Aviation Administration (FAA) downgrade Thailand's safety rating to Category 2. In both instances, the international bodies criticized Thailand's poor safety oversight and lack of adequate oversight in the enforcement of regulatory standards among new and existing airlines.