PPRuNe Forums - View Single Post - EgyptAir 804 disappears from radar Paris-Cairo
Old 2nd Jun 2016, 10:12
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Ian W
 
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Originally Posted by phylosocopter
The "range" of an underwater ping can vary from much less than advertised to very much more, this is because the attenuation is actually fairly low ie water is a very efficient conductor of sound. It is the spreading out of the signal that causes it to diminish , sometimes due to differences in density the signal can be refracted on itself and can even become "ducted" beteween different layers of water. In such case the signal may pop up at a greart distance and not give much info on where the pinger is.+
Which is why the ULB should modulate its signal with the last GPS location as was suggested on the AF447 thread. Just think what could be achieved by a ULB that was more intelligently designed and powered by a battery with a longer life.

And for all the 'what is the hurry we will find it' group - the huge expense of a search of 3 weeks with the possibility that the DFDR/CVR may not be found leading to significant assets being deployed, should be compared to a search that takes a few days and a simple SONAR buoy drop followed by recovery.

I still say that the costs of the search should be charged to the airline (insurance) company. That is the only way that funding will become available for a constructive approach to the retrieval of this information in future crashes. With more transoceanic routes being set up we can expect to see more of these searches not less.
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