Narrative:

A landing aircraft (air carrier X) once on the ground, was asked to report clear of the intersection of an intersecting runway as another aircraft Y was waiting to depart. Aircraft X reported clear of the intersection when he had actually turned on that runway. I cleared the waiting aircraft Y for takeoff. Aircraft Y declined the takeoff clearance as he could see the other aircraft X taxiing on his runway. The tower was in the clouds. Visibility was very limited to nil. Our tower doesn't have asde, so we only have the PIREPS to rely on. It is very common in restr visibility sits to have pilots make inaccurate reports or not report at all. About 5 yrs ago, I filed a report involving the same situation. An aircraft cleared for takeoff when a taxiing aircraft realized he was taxiing on the same runway. We need more than PIREPS to rely on for a safe operation in this type of WX.

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Original NASA ASRS Text

Title: MULTIPLE RWY OP INTERSECTING RWYS ACR X TURNED ONTO ACTIVE DEP RWY. ACR Y REFUSED TKOF CLRNC.

Narrative: A LNDG ACFT (ACR X) ONCE ON THE GND, WAS ASKED TO RPT CLR OF THE INTXN OF AN INTERSECTING RWY AS ANOTHER ACFT Y WAS WAITING TO DEPART. ACFT X RPTED CLR OF THE INTXN WHEN HE HAD ACTUALLY TURNED ON THAT RWY. I CLRED THE WAITING ACFT Y FOR TKOF. ACFT Y DECLINED THE TKOF CLRNC AS HE COULD SEE THE OTHER ACFT X TAXIING ON HIS RWY. THE TWR WAS IN THE CLOUDS. VISIBILITY WAS VERY LIMITED TO NIL. OUR TWR DOESN'T HAVE ASDE, SO WE ONLY HAVE THE PIREPS TO RELY ON. IT IS VERY COMMON IN RESTR VISIBILITY SITS TO HAVE PLTS MAKE INACCURATE RPTS OR NOT RPT AT ALL. ABOUT 5 YRS AGO, I FILED A RPT INVOLVING THE SAME SIT. AN ACFT CLRED FOR TKOF WHEN A TAXIING ACFT REALIZED HE WAS TAXIING ON THE SAME RWY. WE NEED MORE THAN PIREPS TO RELY ON FOR A SAFE OP IN THIS TYPE OF WX.

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.