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 9/19/2001. The game was trademarked on 8/14/2001. 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.
The game was on display at E3 on May 19, 2001. After it was postponed, they were working to change the game cover art to remove sensitive images.
Hopes of a port to another console never materialized. However, a disk image of the game was eventually leaked, and became a popular download on many peer-to-peer networks.