Subsonic

Subsonic is a very high level speed class found only in WipEout HDs Zone Mode. It is the third highest attainable Speed class in the game.

Subsonic occupies zones 50 to 59, and at zone 60, the user will enter the next highest class, Mach 1.

If a player can reach this level in any Zone mode session, having ONLY used the left and right air-brakes (i.e. not used the analogue steering at all), then the Airbraker Trophy will unlock.