Narrative:

Taxiing on ground at seatac, waiting for departure, ground control told us to taxi to runway 34R, hold short of runway 34R at taxiway Q. We got in line (it was afternoon) because it was busy, and waited our turn. For runway 34R, ATC was using full length and intersection Q takeoffs. ATC had given an aircraft instructions to taxi into position and hold full length runway 34R, and he did so, holding in position. Tower then told us to cross runway 34R at taxiway Q and hold short of runway 34L. As soon as he cleared us to cross runway 34R at taxiway Q, he cleared the aircraft holding full length to take off! I immediately stopped and queried the tower controller. I was able to stop in time to avoid crossing the hold short line, and watched as the large turboprop 'whizzed by!' ATC obviously forgot he had cleared me to cross. ATC told me 'sorry' and 'thanks,' and then cleared me to cross runway 34R. The rest was uneventful. Had I not been alert, I'm sure this would have been a situation. An abort at best by the aircraft taking off and/or runway incursion by me. Very dangerous runway confign they were operating -- prone to error -- especially during reduced visibility.

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Original NASA ASRS Text

Title: AN AIRBUS 320 FLC WAS CLRED TO CROSS AN ACTIVE RWY AT SEA. AFTER HEARING AN ACFT CLRED FOR TKOF THE FLC STOPPED IN TIME TO AVOID A POSSIBLE CONFLICT WITH THE DEPARTING ACFT.

Narrative: TAXIING ON GND AT SEATAC, WAITING FOR DEP, GND CTL TOLD US TO TAXI TO RWY 34R, HOLD SHORT OF RWY 34R AT TXWY Q. WE GOT IN LINE (IT WAS AFTERNOON) BECAUSE IT WAS BUSY, AND WAITED OUR TURN. FOR RWY 34R, ATC WAS USING FULL LENGTH AND INTXN Q TKOFS. ATC HAD GIVEN AN ACFT INSTRUCTIONS TO TAXI INTO POS AND HOLD FULL LENGTH RWY 34R, AND HE DID SO, HOLDING IN POS. TWR THEN TOLD US TO CROSS RWY 34R AT TXWY Q AND HOLD SHORT OF RWY 34L. AS SOON AS HE CLRED US TO CROSS RWY 34R AT TXWY Q, HE CLRED THE ACFT HOLDING FULL LENGTH TO TAKE OFF! I IMMEDIATELY STOPPED AND QUERIED THE TWR CTLR. I WAS ABLE TO STOP IN TIME TO AVOID XING THE HOLD SHORT LINE, AND WATCHED AS THE LARGE TURBOPROP 'WHIZZED BY!' ATC OBVIOUSLY FORGOT HE HAD CLRED ME TO CROSS. ATC TOLD ME 'SORRY' AND 'THANKS,' AND THEN CLRED ME TO CROSS RWY 34R. THE REST WAS UNEVENTFUL. HAD I NOT BEEN ALERT, I'M SURE THIS WOULD HAVE BEEN A SIT. AN ABORT AT BEST BY THE ACFT TAKING OFF AND/OR RWY INCURSION BY ME. VERY DANGEROUS RWY CONFIGN THEY WERE OPERATING -- PRONE TO ERROR -- ESPECIALLY DURING REDUCED VISIBILITY.

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.