The ATSB has released a second interim factual report on the Piper Cheyenne accident on 28 July 2004 in which the pilot and five passengers died.
The ATSB has established that the aircraft diverged between 3.4 and 4 degrees left of the intended track between a point abeam Ulladulla and where it disappeared from radar.
The ATSB is conducting further tests of the modes and functionality of the GPS receiver type that was used on the aircraft, to determine if the flight path can be replicated with a copy of the data used by the pilot.
The damaged GPS data card has been sent to the Bureau d'Enqutes et d'Analyses (the French equivalent of the ATSB) for further detailed examination.
The air traffic control Route Adherence Monitoring (RAM) system issued three alerts that the aircraft had diverged from its planned track between Ulladulla and Benalla.
The air traffic control air situation display provides controllers with an automatically triggered alert when a variation is detected by radar, between the planned track and the actual track being flown.
The controllers' response to the RAM alerts is still being investigated.
The investigation is continuing.
The interim factual investigation report (200402797) is available from the website, or from the Bureau on request.