Phu Cat Medivac Chopper

US Army medical evacuation helicopter landing on ramp at Phu Cat, Vietnam - 1972. I think the aircraft is a variety of a Bell Huey. Not sure how much protection was guaranteed from enemy fire by the white paint job and red crosses. Doors on chopper are open with two crewmembers watching for arrival of some patients. I had an experience to be on a white DC-9 medivac jet with red crosses ... nicknamed the Nightengale it was equipped with medical gear, and configured to accommodate hospital stretchers.