Wed Oct 09, 2013 11:28 pm
In my experience, GPS and DME distances aren't significantly different unless you're very high over a nav aid where the slant angle makes a more significant difference.
The two GPS systems each have their own antennas and IAUs, and provide two totally independent sources of GPS data. To loose both is highly unusual and frustratingly it's been happening ever since, despite numerous swapping out of parts for fault finding. It's giving our engineers a major headache to get to the bottom of. As the aircraft is so new, Pilatus are actually sending someone out here to come look into it as a warranty issue.
I do carry my iPhone and iPad, both of which have basic topographical maps on them from Delorme (as part of their inReach SE tracking unit), so I could easily fire one of those up if the worst came to it. Papua's not a place to be chancing your luck and you really need to be fully aware of where you are at all times, especially when the wx is bad.
I'd read about Garmin's dead reckoning mode in the AFM and Garmin's G950 manual but this was the first time I'd seen it in action. Very impressive and whilst you wouldn't want to be flying IMC with it, it's surprisingly accurate considering I was having to made some rather steep turns/descents to drop between the clouds and valleys to get into my initial destination.
And lordbonville, I'm assuming your comment was in jest but in-case you were being serious I'm perfectly capable of flying with visual reference to the ground thanks; although the VFR maps for this area are rather poor and not much more than topographical charts, so one has to rely on local knowledge more than charts. I'm also quite happy shooting any kind of IFR approach out there (inc. NDBs, although thankfully Indonesia doesn't use these any more).
Matt DeardenIn the jungle somewhere...
My Blog: http://www.bushflyingdiaries.com