There were no reports of injuries or damage to the chopper.
“Six national park officers were in the AS350 helicopter, performing a monthly survey of the forest and looking out for any encroachment,” the department explained.
“The pilot reportedly saw a man and a woman dashing into a hut that was built in a protected area after they spotted the chopper approaching. The man subsequently ran out with a homemade gun and fired a round towards the rear of the helicopter, but the bullet missed,” the department added.
After the incident, the pilot landed the chopper at the Jai Phaen Din ranger base about 7 kilometres away.
A preliminary investigation found no damage to the helicopter and no officers were injured.
The department said that officials have filed a case with Kaeng Krachan police station to track down the shooter and the woman, who were believed to be encroaching on national forest land.