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Old 3rd Feb 2010, 10:15
  #6111 (permalink)  
BEagle
 
Join Date: May 1999
Location: Quite near 'An aerodrome somewhere in England'
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Map Datums

Out of interest, can anyone state 'with no doubt whatsoever' that all Lat/Long navigation systems, plus the charts being used, were all using the same mapping datum (presumably WGS 84).

During GW1, it was discovered that some of the 1/2 mill maps had incorrect postions for things like aerodromes. I seem to recall that KKIA was nowhere near where the chart said it was, for example. Those few people who had access to GPS (usually hand-held) often found quite a difference between the chart L/L and the GPS L/L.

GPS was relatively immature at the time of the Chinook crash; even when the first few VC10s were fitted with GPS/LINS, we occasionally obtained larger than expected position errors - and found that some of the GPS hadn't been delivered set to WGS 84....

I don't want to embark on another 'little green men with wacky wirelesses' wild-goose chase, but it could just be another reason for the crew to think that they were somewhere else than their actual location - especially if the GPS was confusing the STANS with mis-matching grid origins and positional information?

Perhaps someone who has done the 'hard sums' course could offer an opinion?
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