Narrative:

I mistakenly thought I was turning onto runway 6 from taxiway D rather than from taxiway a. (I was instructed by ground to hold short of runway 12R on runway 6.) my first officer and I both noticed we were about to cross the runway 12R hold short line when we both applied heavy braking. The aircraft's nose stopped approximately 10 ft beyond the runway 12R hold short line. Fatigue played a factor in my lack of positional awareness. The aircraft's system, including braking system, were functioning normally -- we had no brake malfunction.

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Original NASA ASRS Text

Title: A JS41 CREW, TAXIING FOR TKOF AT STL, CROSSED A HOLD SHORT LINE WITHOUT A CLRNC.

Narrative: I MISTAKENLY THOUGHT I WAS TURNING ONTO RWY 6 FROM TXWY D RATHER THAN FROM TXWY A. (I WAS INSTRUCTED BY GND TO HOLD SHORT OF RWY 12R ON RWY 6.) MY FO AND I BOTH NOTICED WE WERE ABOUT TO CROSS THE RWY 12R HOLD SHORT LINE WHEN WE BOTH APPLIED HVY BRAKING. THE ACFT'S NOSE STOPPED APPROX 10 FT BEYOND THE RWY 12R HOLD SHORT LINE. FATIGUE PLAYED A FACTOR IN MY LACK OF POSITIONAL AWARENESS. THE ACFT'S SYS, INCLUDING BRAKING SYS, WERE FUNCTIONING NORMALLY -- WE HAD NO BRAKE MALFUNCTION.

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.