A SAAB 340 aircraft was conducting a right circuit for a landing on runway 34 right at Sydney, NSW. The aircraft subsequently positioned itself behind a Boeing 767 on final approach to runway 34 left, infringing wake turbulence separation standards.
The crew report that the controller had inquired while the aircraft was downwind if they would like a radar vector to slot them between to heavy aircraft inbound for runway 34 left. The subsequent vector for base leg was assumed by the crew to be a right base, for runway 34 left. The crew did not recall hearing the controller refer to the assigned runway at any stage of their approach. On being cleared for a visual approach at approximately 10 miles the crew dialled up the runway 34 left ILS.
The controller observed the SAAB flying through the centreline of runway 34 right at approximately 7 miles. The crew was cautioned about wake turbulence, taken out of the landing sequence and processed for a right-hand circuit for runway 34 right. The aircraft landed safely without further incident.