Air Force Commander in Chief ACM Prachin Jantong said the craft is a CH46 Sea Knight.
Prachin said headquarters had already located the chopper. One of the 8member crew was injured.
Initial reports said it had made an emergency landing in a valley in the northeastern part of Phitsanulok. “Such a landing is not dangerous,” he said.
Prachin said the US and the Thai air force would send aircraft to the site to help retrieve the chopper.