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Old 10-27-2010, 03:13 PM
  #3  
rickair7777
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The FAA has assigned conversion values which do not have a very good mathematical correlation to each other. I know these off the top of my head...

1SM / 5000
3/4 SM / 4000
1/2 SM / 2400
1/4 SM / 1600

You can use reported vis instead of RVR for CAT-I and non-prec approaches only. CAT-II/III require RVR.
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