This was at the Avalon airshow in Geelong - i was there woo! Australia still uses the ex US F-111's we got after (or during?) vietnam - soon to be replaced by the JSF when / if it ever finishes development.
This is the usual F-111 party trick. There is a fuel dump nozzle at the back of the plane which is used to get rid of excess fuel before emergency landings etc, but i guess someone discovered that it looks impressive if you set it on fire

GO TEAM.