Originally Posted by alystra
Getting rid of Deviation as much as possible IS important though. After all, your brand new chart plotter could
fail at the same time that your crew stands on
the old GPS which you've kept as a backup
, and the pocket GPS
that you use when climbing mountains just runs out of battery
and suddenly the fog comes down so thick you can't see a hand in front of you
- and then
where would you be if you hadn't sorted your Deviation? Lost, that's where you'd be.
And of course you have your pitot speedo calibrated so that you can do a speed - time distance calc........
I say that half jokingly, but as my engine has a pitot take- off at the front of the leg, for a couple of metres of hose and a cheap gauge, it's not a huge cost add- on. At risk of hyjacking the thread slightly, my "e-nav failure" risk assesement goes something like this:
- Backup "toy" is a Garmin handleld (with "data out" patchable to the VHF for DSC emergencies) It;s normally fed from the onboard battery, but with set of charged AAs in to take care of the next level of failure-
- Electrical. Battery dies. Engine is a 2-stroke and has an E- start pull cord. Handheld under the seat. Garmin takes over, and is filled with a load of salient waypoints in case of the aforementioned fog.
- Next level of failure is total satellie death. Highly unlikely, but that's where the compass & a laminated chart comes in to play. (and my comments about the pitot speedo)
There are other engine failure resulting in no battery charging scenarios I've looked at, but as that's going well off topic I'll leave them for another thread.....