The air force will apply thermal imaging on the fourth day of the search for its missing helicopter and three officers on mountainous terrain in Chanthaburi province on Tuesday.
ACM Suttipong Inseeyong, commander of the air force's air operation control, said on Monday that an unmanned aerial vehicle (UAV) with thermal imaging equipment is to be used in conjunction with more people on the ground to locate officers missing with the UH-1 helicopter since Saturday.
Thermal imaging would be effective through cloud and fog but a UAV flight could be difficult if it rained, the commander said.
Special warfare army soldiers would be deployed on Tuesday in addition to about 400 soldiers and villagers in the search and rescue mission.
Air force chief-of-staff ACM Johm Rungswang said on Monday that bad weather was a major obstacle to the mission and that to find the missing helicopter, rescuers would walk up to the peaks and then return downhill. They would camp on the mountain.
The sooner they find the officers, the higher their chance of survival, he said.
The location of the helicopter should be not too far from its Chanthaburi takeoff location because it had not yet reached a high altitude when it disappeared from radar, ACM Johm said.
The helicopter was transporting telecommunications equipment and food supplies from Don Muang to a radar station in the adjoining area of Khao Chamao and Khao Wongkot mountains in Khaeng Hang Maew district of Chanthaburi. It disappeared from radar at 2pm on Saturday after taking off from the radar station.
On board the missing helicopter were Sqn Ldr Pasith Techasen, the pilot, Capt Alongkorn Chankrachang, the co-pilot, and Sgt Maj Visut Puttharaksa, a mechanic.
Helicopters, drones and paramotors have been used in previous searches.
More soldiers are deployed to support the search and rescue mission in Chanthaburi province. (Army photo)