The commercial start of the upgraded facilities at U-tapao airport in Rayong is facing another setback after the discovery of some critical safety issues.
A recent audit by the Civil Aviation Authority of Thailand (CAAT) found about 40 problems, mostly to do with safety, related to the 1.7-billion-baht expansion scheme.
The revelations have pushed back the opening to the extent that the U-tapao Airport Authority (UAA), operating under the Royal Thai Navy, will not commit to an inauguration date.
"We want to spend time to prudently address all the issues raised by the CAAT and make sure that the airport is absolutely perfect before declaring the full-scale opening," UAA director Worapol Tongpricha told the Bangkok Post.
The shortcomings discovered by the CAAT, which acted on a request by the UAA, are compounding the teething problems previously uncovered after the new passenger terminal was put through an intensive trial run and found to need adjustments.
The upgraded U-tapao airport had been due to open in August. The date was later pushed back to the end of 2017, but that timeline is now in doubt.
Contributing to the delay is the installation of two sets of aerobridges, a project that is behind schedule and expected to be completed towards the end of the year.
The CAAT applied its audit in strict compliance with the standards of the International Civil Aviation Organization. ICAO earlier this year advised Thai airports to come up with more comprehensive security plans in accordance with global standards.
The UN's aviation watchdog has placed an emphasis on observing tight security rules at major airports such as Suvarnabhumi and Don Mueang.
The UAA has assured that U-tapao's new passenger terminal with 20,000 square metres of floor space and its supporting facilities remain operational to accommodate the small number of passengers transiting through.
The new passenger terminal is designed to handle 3 million passengers a year, a significant increase from the 870,000 handled previously.
Meanwhile, U-tapao reached a historic milestone by handling more than 1 million passengers in the fiscal year to September, according to Rear Adm Worapol.
Preliminary figures showed that 1.1 million passengers passed through U-tapao in fiscal 2017, up from 710,000 in the previous fiscal year, and 80% were AirAsia passengers.
U-tapao is growing in importance as a new gateway to Thailand for Chinese tourists.
Budget airlines Nok Air and Thai Lion Air have made U-tapao airport their new base for charter flights to China.
This month, Nok Air will gradually open new services from U-tapao to Yinchuan (once a week), Haikou (three times a week), Changsha (three times a week) and Linyi (twice a week).
Thai Lion Air today inaugurates charter flights to U-tapao from Changsha, part of a series of Chinese cities that the low-cost carrier plans to link to U-tapao.