The pilot of VH-KWG called Essendon tower saying words to the effect that "he was just down from Mildura, a bit short on fuel and requesting an approach to the airstrip on the left". The Essendon tower controller checked his radar screen and noted a primary return on a left base for runway 16 at Melbourne. The return was confirmed as being KWG. At the same time a B727, VH-ANB, was joining final for runway 16 approximately three miles behind KWG. The Essendon tower controller coordinated with the Melbourne tower controller to divert ANB to avoid a serious conflict on final approach. KWG was retained on Essendon tower frequency and cleared to land on runway 16 at Melbourne.
Investigation revealed that the pilot was from another state and not familiar with the area. He had planned a flight from Mildura to Wangaratta. He was using a portable GPS but its battery went flat during the flight and its DC power supply system was not working. Having lost GPS information, he tuned the aircraft's ADF to Wangaratta but did not check the morse code identifier. Furthermore, there were isolated thunderstorms in the area and the pilot had been diverting around cloud en route. He did not have an Enroute Supplement or an ERC Low or a WAC chart. He was carrying an ONC chart. He reported that he followed the ADF needle until he saw Melbourne Airport where he finally landed.