Narrative:

After holding for over 1/2 hour over akn VOR, zan advised us the WX at king salmon had improved to 1/2 mi visibility giving us legal approach minimums. We started our descent for the ILS approach and was switched over to akn approach control. Approach read us the WX, reporting the visibility to be 1/2 mi with 'RVV 5/8.' being familiar with 'RVR values,' both of us questioned what was meant by the 'RVV value' issued and if RVV was a controling value. The captain at that point looked in our flight operations handbook and the manual to find RVV value term. During that short time, he could not resolve the question of RVV values being controling. I also attempted to locate the information about RVV values in the few mins available prior to the approach phase without success. Approach then reported the visibility of 1/2 mi with RVV of 3/8. At this time the captain told the approach controller of our confusion over the RVV report. He explained that we were familiar with 'RVR values' but unfamiliar with 'RVV' and asked for an explanation. He reported that RVV was normally given to military aircraft, but did not know if it applied to us. We then told him that our plate minimums were for prevailing visibility and made no reference to RVV values and asked him to confirm the prevailing visibility of 1/2 mi. Approach confirmed 1/2 mi so we asked for and was given vectors for the ILS approach followed by an approach clearance. We flew the ILS as charted and determined the visibility was considerably better than the 1/2 mi reported. The controller should not have given us conflicting visibility reports of 1/2 and 3/8. Also, 'RVV values' are never put on our charts for reference to approach minimums. After researching this matter, the next time I am given 2 conflicting reports of visibility the lesser of the reports will be controling.

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Original NASA ASRS Text

Title: ACR FLC CONFUSION OVER THE USE OF THE TERM 'RVV' IN IAP ILS APCH. MAKES UNAUTH APCH LNDG.

Narrative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

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.