FS2004 Voice Pack Mods Edgar Percival EP.9. Voicepack modifications for the Edgar Percival Prospector EP9 a light utility aircraft of the 1950's for agricultural use, the first prototype flew in 1955. Edgar Percival Aircraft Ltd not to be confused with his original company Percival Aircraft Company Ltd which had become part of the Hunting group by this time. In 1958 Samlesbury Engineering Limited bought the rights to the design of the EP.9 and the company was renamed the Lancashire Aircraft Company. By Mike Stallwood.