Gavin Grimmer
This direction/route (shown in pink in the image below) takes him out across to the Lake McKenzie area where a helicopter was heard high up heading over Lake McKenzie.
Then, a little north, at Routeburn Flats he was heard again "above clouds" although I would say "in cloud", as the observer there said, "The sound from the chopper was a drone noise. It didn't sound like it was in trouble but it was certainly going slower. It didn't sound to be going at any great speed at all. It was certainly completely different to the normal choppers that fly over."
This report is very likely describing the situation of HNW being flown IMC (Instrument Meteorological Conditions) climbing in cloud.
Somewhere on this climb out in the cloud, or when he was at Lake Adelaide, when he just happened to be on a bearing to Milford of 272° magnetic, he pushed "GO TO" Milford on his GPS and this gave him a heading to turn back towards Milford, and it also gave him a reference line out of the valley (shown on the GPS map page) to fly to whilst in the cloud.
If you calculate this section of the track from Lake Adelaide at a reduced ground speed of 60 kts (1 nm/min) and add it to the calculated time at Lake Adelaide, this places HNW directly over the spot that this observer heard the helicopter as being 8.49 am - the exact time of first contact with Milford Flight Service!
Not only that, but if you continue on, you will find the 9 miles out point is almost 6 miles (6 mins) away and it was another 22 seconds till he announced he was turning onto 272, so the point he intersected the 272 heading was roughly 8.66 miles out from Milford (20 seconds = .33 nm). The purple line shown on the image below is the 272°magnetic heading to Milford.
There is doubt as to whether Cam first made contact with Milford at 8.49 am, or if he contacted them sooner, and 8.49 was quoted as being the exact time that he was 9 miles out. Either way, you'll have to agree that the timings are very close.
You can juggle the figures around a bit by cutting the corners on the tracks or extending the distance covered by going wide on the corners, etc., but it all comes back to being very close.
However, there certainly isn't time available for him to have been in all these positions and then be out on the western coast as I had previously thought!
For HNW to be able to be at all these observation points over a period of 54 minutes means that it didn't have time to be anywhere else so this means that Campbell was exactly where he said he was at the time!
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