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Old 9th May 2010, 22:11
  #6 (permalink)  
Join Date: May 2007
Location: Italy
Age: 31
Posts: 204
FMGC says VOR/DME ABC is located bearing 150/20 nm but raw data are 165/21nm. according to FCOM a check is valid if distance difference is less than 3 nm but doesn't say anything about difference in bearing. the above test is then valid or not ? (15 of bearing diff & 1 nm of distance diff)
The accuracy check is done both on distance and bearing:
1. DISTANCE: compare NAVAID distance with FM distance on ND or check with FM PROG page: error shall be less than or equal to 3 NM (1 NM on approach).
2. BEARING: Check that the needle (raw data) overlies the corresponding blue navaid symbol (FM computed).

Hope that helps,
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