Narrative:

Preflight normal. As before start check initiated visibility started to drop below 1 1/2 mi where it had been stable as fog started to roll in. As we started taxi the tower reported visibility of 1/2 mi. We noted our minimums for runway 24 were 1/4 mi. As we approached the takeoff runway the tower reported a special WX observation of west 1x1/4F. We were told to hold for ny approach departure release. As I was talking to load control to get our takeoff data, I heard the tower report visibility 1/8 mi and that we were released if we were ready. As we completed the before takeoff checklist and told the tower we were ready they came out with an official WX special of 1/8 mi. As we took the runway I pointed this out to the captain. He asked if I was uncomfortable with the takeoff. Outside I could see 15-20 runway lights, the visibility at the runway was well over 1/2 mi with nearly all of it in sight. I said I thought the takeoff was safe but that it was not technically legal. The captain asked the tower to repeat the WX, told them we had more than 1/2 mi and we were ready for takeoff. The rest of the flight was uneventful. I had completed my duties to advise the captain per our FAA approved company manual and it was his decision, but there is no reason not to have RVR at a busy field such as long island, macarthur. In foggy conditions the visibility at tower is not a realistic criteria. With RVR this situation could have been avoided.

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Original NASA ASRS Text

Title: ACR MLG MADE TKOF WITH WX REPORTED BELOW REQUIRED MINIMUMS.

Narrative: PREFLT NORMAL. AS BEFORE START CHK INITIATED VISIBILITY STARTED TO DROP BELOW 1 1/2 MI WHERE IT HAD BEEN STABLE AS FOG STARTED TO ROLL IN. AS WE STARTED TAXI THE TWR RPTED VISIBILITY OF 1/2 MI. WE NOTED OUR MINIMUMS FOR RWY 24 WERE 1/4 MI. AS WE APCHED THE TKOF RWY THE TWR RPTED A SPECIAL WX OBSERVATION OF W 1X1/4F. WE WERE TOLD TO HOLD FOR NY APCH DEP RELEASE. AS I WAS TALKING TO LOAD CTL TO GET OUR TKOF DATA, I HEARD THE TWR RPT VISIBILITY 1/8 MI AND THAT WE WERE RELEASED IF WE WERE READY. AS WE COMPLETED THE BEFORE TKOF CHKLIST AND TOLD THE TWR WE WERE READY THEY CAME OUT WITH AN OFFICIAL WX SPECIAL OF 1/8 MI. AS WE TOOK THE RWY I POINTED THIS OUT TO THE CAPT. HE ASKED IF I WAS UNCOMFORTABLE WITH THE TKOF. OUTSIDE I COULD SEE 15-20 RWY LIGHTS, THE VISIBILITY AT THE RWY WAS WELL OVER 1/2 MI WITH NEARLY ALL OF IT IN SIGHT. I SAID I THOUGHT THE TKOF WAS SAFE BUT THAT IT WAS NOT TECHNICALLY LEGAL. THE CAPT ASKED THE TWR TO REPEAT THE WX, TOLD THEM WE HAD MORE THAN 1/2 MI AND WE WERE READY FOR TKOF. THE REST OF THE FLT WAS UNEVENTFUL. I HAD COMPLETED MY DUTIES TO ADVISE THE CAPT PER OUR FAA APPROVED COMPANY MANUAL AND IT WAS HIS DECISION, BUT THERE IS NO REASON NOT TO HAVE RVR AT A BUSY FIELD SUCH AS LONG ISLAND, MACARTHUR. IN FOGGY CONDITIONS THE VISIBILITY AT TWR IS NOT A REALISTIC CRITERIA. WITH RVR THIS SITUATION COULD HAVE BEEN AVOIDED.

Data retrieved from NASA's ASRS site as of August 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.