Narrative:

When coming in range of lns, first officer, PNF picked up ATIS and reported 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 airport. We were cleared for the ILS and proceeded inbound. It looked like the airport 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 approach to decision ht and went missed approach. We then realized that ATIS said visibility was one-eighth mi, below the 1/2 mi required. The situation 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 report it as 1/8 mi because landing minimums are 1/2 mi and takeoff is 1/4 mi. In addition, the 'th' sound does not always come over clear on the radio. Hence, the aim pronouncing three as tree. When visibility is less than 1 mi I think it should only be reported as one half, one quarter, or three quarters, and using less than or greater than for in between visibilities.

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Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.