Flight Hat Yai International Airport departs from Hat Yai Hat Yai International Airport at 11:05 and arrives at Singapore Changi Airport at 13:40.
The flighttime is about 1h 35m. The distance travelled ("as the bird flies"): 420 Km. So the average speed is roughly 265 Km.
There is an 1 hour time difference between Hat Yai and Singapore