This Site is dedicated to all those families of the people that have tragically disappeared on flights in and around New Zealand. I only hope that from all the effort in building this site and from all the effort of those taking part in this venture, that it will bear fruit in bringing ‘closure’ to their memories!
Gavin Grimmer
An illustration of a high-altitude tropospheric duct.
This system is more common with UHF radio signals and known as a “Skip”
It would be more common for a VHF signal to travel north/south when it is caused
by the setting sun as the hot/cooling air is at right angles to the sun, whereas
we know that there was a southwesterly cold front coming up the coast at the time
the Turner’s were flying. This would mean that a hot air inversion due to this, would
allow the VHF signal to transmit in a northwest / southeast direction.
With Timaru being southeast of the Whataroa / Sealy Pass area, then I have no trouble
believing that this is why Roy’s transmissions, especially his last transmission,
could be heard on both sides of the Island at the same time.
Due to this phenomena, there is no requirement for the Turners to have been in “line
of sight” of Timaru!
Below is some illustrations showing how this can happen.
