"This is a free, open-source combat flight simulator developed by AskMisterWizard.com for the LINUX community. Its roots came from the well-known "classic" flight game known as "GL-117", but this new incarnation has been extensively re-written and improved, and the focus has changed from arcade gaming to World War II combat flight simulation."
https://www.askmisterwizard.com/2019/LinuxAirCombat/LinuxAirCombat.htm
Courtesy Graham Morrison @ Linux-Magazine.com