Which of the multiple final radar positions would you like us to search under?

At this stage there are three radar positions stated or implied as radar ‘fade’ positions of VH-MDX.

They do not appear to be defining the same position with the two most extreme positions separated by around 10 nautical miles.

Considering radar accuracy values, the possibility that VH-MDX kept flying after the last radar position and the terrain and vegetation of the Barrington ranges, searching all three areas is not an effective plan.

Significant progress has been made by us in 2014-2015 in defining and understanding what each of these positions means. From this we have determined:

– That one was unlikely a ‘fade’ position but rather, a refined intermediate radar position

– Another was not likely to be a ‘fade’ position but could offer solid tracking guidance for the last few minutes of flight

– One position was likely representative of a radar fade position.

Unfortunately, the position found representing radar fade was defined with significant tolerances that when combined with the terrain and vegetation of the Barrington ranges, results in an area that cannot be searched in any reasonable time frame.

Furthermore, we have found that radar fade likely occurred around 5900′ to 6400′ above mean sea level and in the geographical area that this was possible, VH-MDX may have flown on from the radar fade area.

We have also determined that Sydney ATC did observe VH-MDX radar fade but that Williamtown ATC did not.