This piece originally ran in the June 2021 issue of EAA Sport Aviation magazine.
Back in the mid-1960s, William Leighnor, EAA 8583, was asked by his cousin, an avid sailplane pilot, if he could develop a more accurate flight recorder than what was generally available at that time. Before the advent of electronic flight recorders, sailplane pilots, especially those looking to set sanctioned records, relied on electromechanical devices called barographs that recorded altitudes, based on pressure changes just like an altimeter, on a rolling tape. In true EAA spirit, William looked at the state of the art and realized he could do better, documenting the process in a story in the May 1966 issue of EAA Sport Aviation. This early version of the Leighnor Flight Computer was donated to the EAA Aviation Museum by William’s son.