Gavin Grimmer
28 November 2012
As many of you will know by now, on the 21st November 2012, ZK-HNW was discovered by chance by Southern Lakes helicopter pilot, Brendan Hiatt, as he was flying tourists through the Humboldt Creek area.
ZK-HNW had suffered extensive damage as it had obviously gone in at high speed, and there was only pieces of it left scattered over a large area.
Not only that, it was above what was normally ‘a lot of the year’ snow line, so hence one of the reasons why no-one had seen it until now.
Our little ‘team’, and myself, then started trying to work out how they ended up there, and why.
It was noticed that the wreckage was found on a heading of 272 degrees TRUE to Milford, not on the 272 degrees MAGNETIC heading that everyone (including myself) thought he was on.
The other mystery was that the wreckage was 11 nm out, not the 9 nm out that Campbell reported that he was.
It was then observed on page 5 of this article, the blue arrow towards the upper RH of the page, showing the direction of where a helicopter was heard and it’s direction of travel.
This position is very close to where it was found, and the direction of travel points directly to where that was!!!
The red line on the main picture above, depicts the direction it was heard from and it’s direction it needed to go to end up where it was found.
Using this information, it then became very obvious that this observation was highly likely to be in the close position of his last transmission.
But why 272 degrees True, rather than the magnetic position as per what is commonly used in Aviation?
It was suggested that maybe his GPS was set to true, so then it was a case of checking to see if the Garmin 195 had the capabilities to be set to true?
On checking in the Garmin 195 handbook , I couldn’t find anywhere where you could specifically change everything to a true heading, until I found the section showing that the automatic variation calculation of the GPS could be changed to a manual input, and hence by placing this value as zero, made the GPS display in true.
Why set a GPS to true? ...Very simple in that it is then easy to work out on a map exactly where you are when referencing it from the GPS, as there is no need for an allowance for the variation. The variation is only needed when using a compass, as True North and Magnetic North are in different directions.
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