A professional pilots' organization has warned that soft ground conditions at Bangkok's main international airport can cause the pavement of its taxiways to buckle or otherwise fail.

The warning issued this week by the International Federation of Air Line Pilots' Association says soft ground or soft spots have been encountered and reported by flight crews and ground service providers at Suvarnabhumi International Airport since at least 2008. The group issued a similar warning four years ago.

The statement says a high water table and faulty asphalt caused failures on heavily transited areas after about two years, rather than the expected pavement life of around seven years. It says the airport's operator had advised that permanent repairs were not expected to begin until at least late 2019.