Whether Roy flew over the top of the cloud, or below the cloud is immaterial as there is problems in the theory either way.
This is borne from the next actual observation in this scenario being from a person inland from the Whataroa Bridge in an area known as Sandy’s Flat, that heard a plane above cloud come across from the Perth River and continued in the direction of the upper Whataroa River Valley.
The most logical “entrance” to the Perth River from the Godley Valley is the Sealy Pass and the problem with the scenario of him being above cloud at 8000’ to 9000’ would mean that he had no reason to transit through the Pass as he would have been above the mountain heights in that area.
The observer at the Round Hill Ski Field at the north eastern side of Lake Tekapo thought that the Godley Valley was impenetrable but that opinion was only from his observation point.
As I’ve said in other places in this website, what may appear as un-flyable to an observer, does not mean that it is so. The observer may be looking through a rain shower, or mist, that is between them and the object they are looking at, and it just appears that way.
I remember waking up one morning and the whole area around where I live (on the southern edge of the cross-vector runway at Bridge Pa was enveloped in fog. I was horrified to hear an aeroplane fly low overhead the fog and then land on the main runway. I was sure that they must have been in trouble to attempt a landing in those conditions, so curiosity got the better of me and I hurriedly drove down the road to see who it was, and if they were alright.... I was surprised to see that the main runway (450 meters away) was in glorious sunlight and the edge of the fog bank was not far from our house!
Taking all this into account, it appears that Roy did fly through the Sealy Pass, into the Perth River Valley - a logical route to go to get to the West Coast. His Flight Plan said that his intended destination was Fox Glacier, his first radio call when airborne was still “bound for Fox Glacier”, his next radio call 25 mins into the flight was to Hokitika (West Coast) to check that the actual weather had not changed from what he had received earlier, and seven minutes later, he asked for the same weather again. He also was very interested in the weather at Franz Josef which Hokitika didn’t have.
As Hokitika had not received an acknowledgement of receipt from Roy to the first weather report given seven minutes earlier, then it is again logical to believe that Roy had not heard the previous report from Hokitika due to the VHF (line of sight) radio signal being shielded by intervening terrain - meaning he had flown out of a “line of sight” position with Hokitika, into the ‘shadow’ of a mountain - a radio blind spot. Which mountain this was, can be calculated using this scenario as most likely being Mt Adams (approx.7200’).
The purple areas shown is where no radio communication with Hokitika would be possible and the green is “line of sight” if flown at a height of 7500’
Page 5 of 15