Delivered to the US Army as 69-18010. Used in Vietnam from 1970 to 1972. Sold as N37778 then to NASA Ames Research Center, NAS Moffett Field, CA as N718NA in 1977 and used as a research aircraft. To NASA Dryden Flight Research Center as N818NA, Edwards, CA in 1997. Sold in 2015 and remained on the register.