This position appears to have been recorded during the post accident search in August 1981 and was included in the 1st September 1981 Air Safety Investigation Report. The position is clearly labeled as a radar fade position indicating where VH-MDX disappeared from RAAF Williamtown ATC radar at 0940UTC (1940EST).
Research has shown that this position was likely determined by RAAF Williamtown vectoring a helicopter to the ‘last’ observed Williamtown radar position of VH-MDX. This position was used as one of the focal points for the initial post accident search as well as many following searches.
When debriefing key personnel involved in the accident, Glenn Strkalj found that this position is unlikely to be a radar fade position but more likely the position of VH-MDX at 0936UTC (approximately 3.5 minutes prior to the final received transmission from VH-MDX) so, an intermediate radar position. This is a very important finding as organisations have interpreted this position as where VH-MDX faded from radar when it actually appears to be a radar fix from which VH-MDX flew on from.
This means that VH-MDX in our current view is unlikely to be located in very close proximity to this position.