National Archives of Australia (NAA) file series A9755 control symbol 8, formerly file number 17/26/AIR was a file titled "Exercise Close Encounter" and owned by RAAF base Williamtown. It is held by the Canberra office of the NAA, is 99 pages long, with a date range of 1983-1983, and has just been released and digitised by the NAA.
Jets on alert:
On 1 Jul 1983, HQ RAAF base Williamtown, NSW, issued an unusual Operational Order, number 11/83. It advised that Williamtown had been tasked "...to provide air defence resources for the identification of unknown radar contacts reported by Department of Aviation (DOA) air traffic control agencies in Sydney. The radar contacts, travelling at high speed, have appeared to the north of Sydney out to 150nm and have been assessed by D of A as almost certainly resulting from man-made objects..."
Two Mirage jet aircraft were placed on alert to take off and intercept any future contacts. Restrictions on supersonic flight were waived.
By 2 Jul 1983 further information was known. "The majority of reported tracks to generally north of WLM usually heading in a northerly direction 355-030 and fading toward the limit of Sydney radar coverage 150-165nm.
The RAAF's own radar failed to see any such tracks. A suspicion arose in the RAAF personnel's mind that the issue was "...a radar fault causing the majority of these observations..."
The final report by the RAAF investigation team of three Air Defence Controllers, who went to Sydney radar to investigate included the following:
"The investigation team proved beyond reasonable doubt by Sunday 3 July 1983 that the unidentified objects were generated entirely from interference with the processor of the Sydney Route Surveillance Radar (RSR.)"
The jets were stood down and so ended one of the few RAAF alerts in response to the phenomenon.
This wasn't the only time that Sydney radar was reported to have picked up unusual objects on their radar. NAA file series A 6180 control symbol 6/6/74/83 is a single photograph which is labelled "Research-scientists probe the sky at
To take a look at the digital file for Exercise Close Encounter, go to here , click on search the collection, then begin your search, then RecordSearch Advanced search, then click on items, then in the box labelled series number type A9755 and in item control symbol type 8. Click on search and the file comes up, click on the digitised file image and read the file.