AT ORD; AN MD80 CAPT MADE A L TURN AT INTXN TXWYS M AND T TOWARD RWY 9 BELIEVING HE WAS ON TXWY T AT INTXN T10. ACFT LNDG RWY 9 WENT AROUND.

Narrative

AFTER DEPARTING THE GATE OUR TAXI INSTRUCTIONS WERE 'TURN R ON ALPHA; A-15; B; M2; M; T; 32L; T-10.' AS I TAXIED ON TXWY M APCHING TXWY T THE FO WAS 'HEAD DOWN' COMPLETING THE BEFORE TKOF CHKLIST AND I WAS MAKING THE PREPARE FOR TKOF PA. I STOPPED THE ACFT AT THE INTXN OF TXWYS M AND T (IN THE HS10 BUBBLE ON THE CHART) AND THOUGHT I WAS ON TXWY T HOLDING ABEAM T10 JUST A SHORT DISTANCE AHEAD AND TO MY R. TWR WAS TALKING TO US AND ONE OTHER ACFT TRYING TO DECIDE WHICH ONE OF US TO CLR FOR TKOF FIRST. WE SAID WE WERE READY; AND HE CLRED US FOR TKOF. STILL THINKING WE WERE ON TXWY T; I STARTED A L TURN ON TO WHAT I THOUGHT WAS T10 BUT WAS ACTUALLY TXWY T. THE TWR CTLR AND I BOTH REALIZED MY ERROR AT THE SAME TIME AND I STOPPED THE ACFT AS HE WAS TELLING ME TO DO SO. WE HAD TURNED WELL LESS THAN 90 DEGS AND NO LOSS OF SEPARATION OCCURRED BUT THE TWR DID ORDER ANOTHER ACFT TO GO AROUND ON RWY 9R; BECAUSE HE DID NOT KNOW IF WE HAD CROSSED THE HOLD SHORT LINE OR NOT. I TALKED TO THE TWR CTLR LATER BY PHONE AND HE WAS STILL UNSURE IF WE HAD VIOLATED THE HOLD SHORT LINE BUT SAID THE GND RADAR TAPES WOULD BE REVIEWED IN THE MORNING. NO EXCUSES; I MADE AN ERROR ON A DARK NIGHT WITH TOO MANY THINGS GOING ON AT ONE TIME IN THE COCKPIT. SUPPLEMENTAL INFO FROM ACN 738731: WE RECEIVED CLRNC FOR TKOF AND I LOOKED DOWN TO FINISH THE CHKLIST. AT THIS TIME THE CAPT MADE THE COMMENT THAT THEY WERE LNDG AND DEPARTING ACFT FROM DIFFERENT DIRECTIONS. I LOOKED UP AND REALIZED THE CAPT HAD TURNED L ON TXWY T INSTEAD OF R AND WE WERE LESS THAN 90 DEGS TO RWY 9R. THE ACFT WAS STOPPED AND I DIDN'T NOTICE THAT WE HAD CROSSED ANY HOLD SHORT LINE. THE TWR TOLD US TO STOP BUT WE ALREADY HAD. THE TWR SAID WE WERE ACROSS THE HOLD SHORT LINE BUT WE DID NOT NOTICE THAT AT ALL. WE WEREN'T EVEN 90 DEGS TO THE RWY. THIS IS A HOT SPOT ON THE ARPT PAGE. WE THEN TAXIED TO RWY 22L AND DEPARTED. ON CLBOUT WE WERE ADVISED TO CONTACT ORD TWR ABOUT A POSSIBLE PLTDEV. I'M STILL NOT CONVINCED WE INCURRED ONTO RWY 9R; BUT IT WAS NIGHT AND WHEN I LOOKED UP I WAS CONFUSED ON THE DIRECTION WE WERE GOING. I AM GOING TO LOOK UP FROM NOW ON WHEN THE ACFT IS MOVING EVEN AT THE EXPENSE OF NOT GETTING THE CHKLIST DONE IN A TIMELY MANNER.