Phillip Neal "Phil" Butler (born August 11, 1938) was the eighth-longest-held U.S. prisoner of war (POW) held in North Vietnam during the Vietnam War. Butler, a Navy pilot, who was forced to eject after a mid-air explosion on April 20, 1965 and served as a prisoner of war in North Vietnam until his release as part of Operation Homecoming in 1973. Butler was one of the five POW's (with Carlyle "Smitty" Harris, Hayden Lockhart, Robert Peel, and Robert H. Shumaker) credited with establishing the tap code. The code enabled the prisoners to communicate with each other.