The Civil Aviation Authority of Singapore (CAAS) has stepped up surveillance and ramp checks on aircraft operated by Thai airlines in response to a recent safety audit by the International Civil Aviation Organization (ICAO) that identified problems with the way Thailand oversees aviation safety. The April 2 move followed decisions over the past week by China, Japan and South Korea to ban new flights by Thai carriers, resulting in cancelations of numerous charter flights. The FAA and the European Aviation Safety Agency have yet to indicate whether they will impose new restrictions on Thai airlines.

The ICAO audit of Thailand’s Civil Aviation Authority was conducted from January 19 to 30 and revealed “some concerns relating to flight operation certification procedures.” According to the UN agency, Thai officials proposed corrective actions and mitigation measures on March 2.

“Please take note though that an ICAO audit does not review the levels of operational safety in a state, or in the airlines or airports, etc., which operate there,” said ICAO spokesman Anthony Philbin. “Rather, our audits review the capabilities of state civil aviation authorities with respect to how they resource and manage aviation safety oversight responsibilities in their jurisdictions.”

CAAS conducts ramp checks as part of its foreign operators surveillance program. Any major safety deficiencies identified by the checks have to be addressed by the carrier concerned for it to be permitted to keep operating in Singapore.