Narrative:

While doing preflight checks; with about 25 mins prior to departure; I noticed the #1 and #2 brake temperatures were over 300 degrees (the #2 brake was over 400 degrees). The first officer and I coordination chocks (which took some time) and the #2 brake was just below 300 degrees at pushback time. I decided to push back and taxi; using only the right brake. During the course of taxiing; which involved a runway change due to a microburst (from runway 25 to runway 34L) and a problem with load planning; the #3 and #4 brakes went over 300 degrees. Tower asked us to hold short of runway 34L at taxiway D2 to let others behind us take off. I elected to not set the parking brake while holding short; but only hold the left brake so the right side could cool faster. That was my mistake. While talking with the first officer about our load planning issue; coupled with it being dark outside and the downhill slope of the taxiway toward the runway; the aircraft crept forward without my noticing it. When the first officer noticed; we were about 4 ft over the hold short line. Shortly after we noticed the incursion (we had previously told tower we were ready to go because our brakes had cooled); we were cleared for takeoff.

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Original NASA ASRS Text

Title: A320 DECIDES TO DEPART GATE WITH HOT BRAKES IN ANTICIPATION OF THEIR COOLING PRIOR TO TKOF. RWY INCURSION RESULTS WHILE HOLDING BRAKES MANUALLY AT HOLD SHORT LINE.

Narrative: WHILE DOING PREFLT CHKS; WITH ABOUT 25 MINS PRIOR TO DEP; I NOTICED THE #1 AND #2 BRAKE TEMPS WERE OVER 300 DEGS (THE #2 BRAKE WAS OVER 400 DEGS). THE FO AND I COORD CHOCKS (WHICH TOOK SOME TIME) AND THE #2 BRAKE WAS JUST BELOW 300 DEGS AT PUSHBACK TIME. I DECIDED TO PUSH BACK AND TAXI; USING ONLY THE R BRAKE. DURING THE COURSE OF TAXIING; WHICH INVOLVED A RWY CHANGE DUE TO A MICROBURST (FROM RWY 25 TO RWY 34L) AND A PROB WITH LOAD PLANNING; THE #3 AND #4 BRAKES WENT OVER 300 DEGS. TWR ASKED US TO HOLD SHORT OF RWY 34L AT TXWY D2 TO LET OTHERS BEHIND US TAKE OFF. I ELECTED TO NOT SET THE PARKING BRAKE WHILE HOLDING SHORT; BUT ONLY HOLD THE L BRAKE SO THE R SIDE COULD COOL FASTER. THAT WAS MY MISTAKE. WHILE TALKING WITH THE FO ABOUT OUR LOAD PLANNING ISSUE; COUPLED WITH IT BEING DARK OUTSIDE AND THE DOWNHILL SLOPE OF THE TXWY TOWARD THE RWY; THE ACFT CREPT FORWARD WITHOUT MY NOTICING IT. WHEN THE FO NOTICED; WE WERE ABOUT 4 FT OVER THE HOLD SHORT LINE. SHORTLY AFTER WE NOTICED THE INCURSION (WE HAD PREVIOUSLY TOLD TWR WE WERE READY TO GO BECAUSE OUR BRAKES HAD COOLED); WE WERE CLRED FOR TKOF.

Data retrieved from NASA's ASRS site as of January 2009 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.