Navigation event - 6 km south of Ballarat, Victoria, on 31 May 2007

On 31 May 2007, the pilot of a Beech Aircraft Corp. Super King Air, registered VH-XCB, was conducting an Area Navigation (RNAV) Global Navigation Satellite System (GNSS) non-precision approach (NPA) to runway 36 at Ballarat, Vic. in instrument meteorological conditions (IMC) as part of a check flight for renewal of a command instrument rating. While conducting the approach, the check pilot on board visually determined that the aircraft was displaced outside the permitted lateral tolerances of the published final approach track. The pilot's primary flight display showed that the aircraft was within permitted tolerances and there were no associated messages or alerts.

An examination of the aircraft's navigation equipment by an avionics technician found that the installation was not approved for the procedure and a technical problem prevented the equipment from meeting approval standards.

The operator of the aircraft annotated the aircraft's maintenance release to reflect that the Global Positioning System (GPS) was not approved for use in the conduct of RNAV (GNSS) NPAs.