Canadian aerodrome minima on Jepp plates

[ATIS]

HI can someone explain what the following visibility minima means.

Eg for any ILS runway. Vis "1 or 1/4"

I know that the "1" means 1 SM, but haven't a clue on the "1/4"

Thanks

[evansb]

Prevailing visibility one-quarter of a statute mile. Reportable values below that are 1/8th, and 1/16th. Above 1/4, are 5/8ths, and 3/4, (three-quarters of a statute mile). RVR values are in feet.

[Bullethead]

G'day ATIS,

If you look in the Jepp World Wide Text, Intro, App Chart Legend, Landing Minimums area you'll see that for Canada and the US RVRs and Vis is given for some approaches. RVR is to be used if reported for a particular runway and the Vis if RVR is not available. RVR is reported in 100s of feet and Vis in miles and quarters. There appears no be no distinction between statute or nautical miles which is odd as there is 800ft difference between the two.

For a chart minimum of RVR 24 or 1/2 this would mean,

RVR of 2400 ft or Vis 1/2 mile.

So in your example the '1' is 100ft or Vis 1/4 mile, which doesn't tie up distance wise, though the '1' should be prefixed by RVR. Vis 1/4 mile is more likely RVR 12.

RVR values are only charted when they are not the same as visibilty values.

Regards,
BH.