Pedzisa mutsara unotevera: Muna October 1965, United States Air Force (USAF) 20th Helicopter Squadron yakaumbwa paTan Son Nhut Air Base muSouth Vietnam, yakashongedzerwa pakutanga neCH-3C helicopters. Pakazosvika June 1967 ari UH-1F uye UH-1P vakanga akawedzera kuti chikwata wacho Inventory, uye pakupera kwegore chikwata yose akanga achinja kubva Tan Son Nhut kuna Nakhon Phanom Royal Thai Air Force Base, pamwe CH-3s uchatamisa kuti 21st Helicopter Squadron. Musi wa 1 Nyamavhuvhu 1968, chikwata ichi chakadudzirwazve kuti 20th Special Operations Squadron. 20th SOS's UH-1s vaizivikanwa se "Green Hornets", zvichibva paruvara rwavo, kunyanya girini maviri-tone camouflage (girini uye tan) yakatakurwa, uye radio call-chiratidzo "Hornet". Basa guru remaherikoputa aya raiva rokuisa uye kubvisa mapoka okuongorora, kupa chifukidziro pamabasa akadaro, kuitisa hondo yepfungwa, uye mamwe mabasa okutsigira mabasa akavanzika zvikurukuru muLaos neCambodia munguva inonzi
Hondo Yakavanzika.