APCHING LNS ARPT TO LAND; FLC RECEIVED THE ATIS BROADCAST AND BELIEVED THE VISIBILITY WAS BEING RPTED AS 18 VICE ONE EIGHTH.

Narrative

WHEN COMING IN RANGE OF LNS; FO; PNF PICKED UP ATIS AND RPTED VISIBILITY AS 18 MI (HE SAID ATIS INDICATED ONE EIGHT MI) WITH FOG. LOOKING BELOW US; I SAW A LAYER OF FOG BUT IT WAS BREAKING UP IN THE DIRECTION OF THE ARPT. WE WERE CLRED FOR THE ILS AND PROCEEDED INBOUND. IT LOOKED LIKE THE ARPT MAY HAVE BEEN UNDER THE EDGE OF THE FOG AND I WAS NOT WORRIED SINCE LNS IS HARD TO SEE UNDER NORMAL CONDITIONS. WE CONTINUED THE APCH TO DECISION HT AND WENT MISSED APCH. WE THEN REALIZED THAT ATIS SAID VISIBILITY WAS ONE-EIGHTH MI; BELOW THE 1/2 MI REQUIRED. THE SIT COULD HAVE BEEN AVOIDED HAD THE ATIS BEEN RECORDED SAYING; VISIBILITY LESS THAN 1/4 MI; 1/2 MI; OR SOMETHING LIKE THAT. THERE'S NO REASON TO RPT IT AS 1/8 MI BECAUSE LNDG MINIMUMS ARE 1/2 MI AND TKOF IS 1/4 MI. IN ADDITION; THE 'TH' SOUND DOES NOT ALWAYS COME OVER CLR ON THE RADIO. HENCE; THE AIM PRONOUNCING THREE AS TREE. WHEN VISIBILITY IS LESS THAN 1 MI I THINK IT SHOULD ONLY BE RPTED AS ONE HALF; ONE QUARTER; OR THREE QUARTERS; AND USING LESS THAN OR GREATER THAN FOR IN BTWN VISIBILITIES.