Joq & Craig Thanks for this information guys - all too often, the magic that goes on behind the scenes is hidden and we lose the opportunity to understand the operation of devices like emergency beacons. Jog, I'm more aware of the Southern (Pacific) Ocean satellite frequency - that is relevant down here in NZ - but our people advise that there may be a 30 minute delay before beacon info is captured by a SARSAT satellite and passed to a ground station. That is simply a fact-of-life resulting from when a satellite may be passing overhead - 30 minutes is worst-case. So, if the flow of 406 info is not continuous to SAR, and the beacon is drifting (wind or tide), then there will be some error in the target position (with which the SAR aircraft is working). So, sometimes, the SAR will arrive overhead target - with a SARSAT satellite in position to give up-to-the-minute GPS co-ordinates (from the beacon) - and sometimes the satellite will be over the horizon and the aircraft will be working on old position info - the last known position when the satellite 'set' below the horizon. I believe that the 406 signal is not currently decoded in the SAR aircraft - it is only handled via the sat-link - so the GPS co-ordinates will be as old (stale) as the last SARSAT satellite pass. I had assumed that it was in this scenario (of stale GPS data) when the 121.5 MHz beacon would come into play - to overcome any drift in that 30 minutes. Once in position where the aircraft's ADF says the 121.5 beacon is 'right here somewhere', I guess the NV gear and Mk 1 Human Eyeball come into play as the best available sensor ;-) As I can't carry flares with me, flying up to Vancouver from Auckland next week - or indeed on the AMHS ferries going up to SE Alaska, I've been considering my options to help that last 'eyeball' phase of the search (that I sincerely trust will never eventuate;-) As far as I know, neither Canadian nor American safety regs require me to carry flares in a sub-6m kayak - but I always have them in my PFD in New Zealand - so it will feel funny not to have them in Alaska. It's also a pity to buy them & throw them away after 3 weeks... I've studied the Magnum Laser Flare for a while - but there seems to be absolutely no move by any regulators to 'accredit' them as equivalent to a pyrotechnic flare - not even for night use. There seems, if anything, to be a tailing off in enthusiasm (judged by the number of outfits selling them) since the surge of interest 4-5 years ago. I may find out more about this in Alaska - as I believe this is where they originated and where SAR did the testing to prove they were completely OK for pilot vision - and that they were pretty effective. I think they got over all those hurdles - but they don't seem to have caught on. The little PLB unit (that I'm going to buy) has a LED emergency white light, which should give sufficient visibility (at night). By day, assuming our VHFs are still working, a VHF talk-through with the aircraft is always going to be helpful - and may be better than any visible signal in SE Alaska's well-known low-viz daylight... However, one comforting thing in an emergency situation is a some redundancy. Weakest links chose the damndest times to break... Best Regards Paul Hayward, Auckland, New Zealand *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Thu Jul 08 2010 - 19:29:55 PDT
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