( HRSs were known as H-19s in the Army and USAF ) HRS = Sikorsky Transport Helicopters Listed on 130413 Listed on their Respective Pages/Sections VMA-311 "TOMCATS" 6th Design at El Toro in the 1970s Marine Aircraft Group-13 (MAG-13) 3rd Design used at Iwakuni, in Vietnam, and at ...