An air force plane carrying Prime Minister Prayut Chan-o-cha to the South returned to Don Mueang airport after an engine problem was reported 45 minutes into the flight on Thursday morning.
The C-130 aircraft, number 60109, had been scheduled to land at Samui airport in Surat Thani province at 8.20am.
After returning, the prime minister and his delegation boarded an army C-295 plane, number 16150, and resumed the delayed trip to Surat Thani and Krabi provinces.
The incident delayed the prime minister's arrival by about one hour and 30 minutes.