The airline industry has called on the Thai government to address problems at the country's main airport in Bangkok.
The International Air Transport Association (Iata) says Suvarnabhumi airport has inadequate capacity and substandard taxiways.
The criticism follows safety warnings last year from another air industry organisation about Thailand's regulation and inspection of airlines.
The government has set up two bodies to oversee airports and airlines.
However, it has asked for more time to meet international standards.
Suvarnabhumi airport was opened nearly ten years ago. It is Thailand's main international gateway but Iata says it is now operating beyond its capacity, and needs to be expanded.
"Aviation is critical to Thailand's economic success. It is the backbone of the tourism industry and provides critical global business links," Iata's director general Tony Tyler said in Bangkok.
"It is in jeopardy, however, unless key issues of safety, capacity and costs are addressed urgently."
The organisation urged the Thai authorities to fix the problem of 'soft spots' in poor quality tarmac at Suvarnabhumi airport, where airliners sometimes got stuck and had to be pulled out.
Mr Tyler said a permanent solution was needed. "There seems to be a constant resurfacing with a temporary patchwork of asphalt reinforcements. Frankly, that is not good enough.
"The runway and gate downtime that results from constantly fixing (and re-fixing) them is unacceptable.
"Moreover the situation is a safety risk. The extraordinary power that aircraft need to use around soft spots and extra-towing expose ground personnel, ground equipment and the aircraft to safety risks.
He also highlighted the issue of lack of capacity at the airport. He said the Phase Two terminal expansion was badly needed and should be fast tracked.
"For runway capacity, immediate capacity increases can be achieved through addressing the "soft spots" issue which will allow existing capacity to be used fully. But a third runway will be needed eventually. So it is important that work and preparations for a three runway system continue," he added.
Thailand is already struggling to address last year's warnings from the United Nation's International Civil Aviation Organisation (ICAO), about a shortage of inspectors to check safety procedures among Thai airlines.
The US Federal Aviation Administration (FAA) subsequently downgraded its safety rating of Thailand's aviation authority, finding that Thailand did not comply with the ICAO's safety standards.
Iata said it was "deeply disappointing" that the organisations had raised safety concerns about Thailand as a country.
It said the oversight concerns raised in both the ICAO and the FAA reports should be addressed by the Thai government "thoroughly and urgently".
The airport's operator, Airports of Thailand, has said it has come up with several measures to improve the runways using concrete and expand capacity. These are awaiting government approval.
"We have prepared short- to medium- and long-term plans to solve the problems," said Sirote Duangratana, general manager of Suvarnabhumi Airport.