Propeller Arena: Aviation Battle Championship is a video game for the Dreamcast console. It was originally titled Propeller Head Online, and was to be released on September 19, 2001. The game was trademarked on August 14, 2001. It was developed and completed by the development team Sega AM2, but the game was never officially released. The release was cancelled just days after the September 11 attacks, citing both similarities in game packaging and design to the events of that day as well as the Dreamcast's declining market share resulting in projected low sales numbers.