The authority said the flights from Bangkok to Chiang Mai, the northern tourist city, had three operators: Nok Air, Thai AirAsia, and Thai Lion Air, who offered a maximum of 10, 13, 5 flights per day, respectively.
Thai AirAsia charged the highest ticket fare at 5,299 baht, or 9.36 baht per km, while Nok Air offered the cheapest air ticket at 980 baht, or 17.3 baht per km.
For flights from Chiang Mai to Bangkok, Nok Air operated a maximum of 11 per day, Thai AirAsia 13 per day and Thai Lion Air 5 per day.
The most expensive tickets were from Thai AirAsia at 5,299 baht, or 9.36 baht per km, while the cheapest tickets were offered by Thai Lion Air, at 1,245 baht, or 2.2 baht per km.
For Hat Yai, the southern tourism and economic hub in Songkhla province, Nok Air operated a maximum of three flights from Bangkok per day, Thai AirAsia 8 and there were four by Thai Lion Air.
Thai AirAsia had the highest ticket fare at 6,122 baht, or 7.92 baht per km., while Thai Lion Air offered the cheapest air fare at 645 baht, or 0.83 baht per km.
Nok Air operated a maximum of three flights per day from Hat Yai to Bangkok, Thai AirAsia eight per day and Thai Lion Air five per day.
The most expensive tickets were from Thai AirAsia at 6,122 baht, or 7.92 baht per km, while the cheapest tickets were offered by Thai Lion Air, at 900 baht, or 1.16 baht per km.
Nok Air flies a maximum of six flights a day from Bangkok to Phuket, the popular island in the Andaman Sea, there are 13 flights per day by Thai AirAsia, and four flights per day by Thai Lion Air.
The most expensive tickets were from Nok Air at 6,447 baht, or 9.24 baht per km, while the cheapest tickets were offered by Thai Lion Air, at 745 baht, or 1.07 baht per km.
Nok Air operated a maximum of seven flights per day on the Phuket- Bangkok route, Thai AirAsia had 13 and Thai Lion Air seven.
Nok Air tickets were the most expensive at 6,447 baht, or 9.24 baht per km, while Thai Lion Air offered the cheapest tickets at 1,445 baht, or 2.07 baht per km.
The CAAT also reported that among domestic flights covering a distance of over 300km, Thai Lion Air had the lowest average price at 3.2 baht per km, while Thai AirAsia had the highest average price at 6.09 baht per km.