Near collision 2014 - unknown object - Perth - the official report released

Background:

In two previous blog posts, (click here and here) I reported that eagle-eyed  Melbourne researcher, Paul Dean, had spotted an interesting Australian Transport Safety Bureau preliminary report. This report concerned a near collision between an "unknown object," and a De Havilland DHC-8 aircraft, registration VH-XFX, near Perth international airport on 19 March 2014.

FOI requests:

In jointly researching the incident, Paul Dean submitted an FOI request to Air Services Australia, asking for a copy of radar coverage around the time of the incident. Paul received the relevant radar data. Paul kindly sent me a copy of the data, and at run time 0106 the DHC-8 aircraft appears on the screen, and it, and surrounding commercial aircraft can be followed, until they land at Perth. No "unknown object" appears on the screen. As this data is from secondary radar, no object appears on the screen unless it is carrying a transponder. One can deduce from this, that the unknown object was not an aircraft.

Meanwhile, with Paul's concurrence, I simultaneously submitted an FOI request to the Department of Defence, seeking a copy of any primary radar coverage from RAAF Perth, around the time of the incident. This FOI request was refused, on the grounds, that as the relevant radar tape had been re-used, in line with standing orders, and there was no such "document" that they could provide to me. I had been hoping that primary, as opposed to secondary radar, would show the "unknown object." Memo for next time is that one needs to submit an FOI request to the DOD immediately after an incident. This of course assumes that you hear about it right away. This was not the case with this particular incident.