From Wikipedia:
It is unclear if Heath, anxious to fight in World War II, graduated high school; in a 2004 interview, he recalls going "into the Air Force in my senior year of high school, in 1945," after having been "put in an accelerated class so I could get through with high school. I almost made it, but then the Air Force called me and in I went".[2] He served stateside for nine months, drawing cartoons for his camp newspaper, but due to a clerical error, he said, he was on neither the military payroll nor any official duty roster for a significant portion of his time. Upon his discharge, he lived at home on a one-year military stipend of $20 a week before working as a lifeguard at a swim club, where he met his future wife.