Narrative:

While taxiing; I crossed the hold short line of the active runway. Air carrier returned to the gate with 2 aborted takeoff attempts due to the takeoff warning horn sounding. At the gate following the fault isolation manual/chart; I could not duplicate the fault. I also performed the takeoff warning test per the maintenance manual. The test passed -- no faults. I also inspected the takeoff warning switches (flaps; stabilizer; speed brake) for condition and security. I determined that I would try to duplicate the conditions the pilots had. This would mean running the engines at a high power setting. We requested from the tower a place where we could perform a power run and was told that we could use the inactive runway (my understanding). We taxied to the runway and I advanced throttles past 33% (to activate the takeoff warning system) with park brake released. I taxied for a short time to see if the fault would occur with the throttles advanced. No warning horn. I returned throttles to idle and started braking action. I was not able to make the taxiway east turnoff and deployed thrust reversers to stop as quickly as I could. I was not aware that the active runway was the next intersection. When the aircraft was stopped it was approximately 1/2 airplane over the hold short line.

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Original NASA ASRS Text

Title: A B737-300; OPERATED BY 2 TECHNICIANS; TAXIING THE ACFT ON AN INACTIVE RWY FOR TESTING INADVERTENTLY CROSSED THE HOLD SHORT LINE OF AN ACTIVE RWY.

Narrative: WHILE TAXIING; I CROSSED THE HOLD SHORT LINE OF THE ACTIVE RWY. ACR RETURNED TO THE GATE WITH 2 ABORTED TKOF ATTEMPTS DUE TO THE TKOF WARNING HORN SOUNDING. AT THE GATE FOLLOWING THE FAULT ISOLATION MANUAL/CHART; I COULD NOT DUPLICATE THE FAULT. I ALSO PERFORMED THE TKOF WARNING TEST PER THE MAINT MANUAL. THE TEST PASSED -- NO FAULTS. I ALSO INSPECTED THE TKOF WARNING SWITCHES (FLAPS; STABILIZER; SPD BRAKE) FOR CONDITION AND SECURITY. I DETERMINED THAT I WOULD TRY TO DUPLICATE THE CONDITIONS THE PLTS HAD. THIS WOULD MEAN RUNNING THE ENGS AT A HIGH PWR SETTING. WE REQUESTED FROM THE TWR A PLACE WHERE WE COULD PERFORM A PWR RUN AND WAS TOLD THAT WE COULD USE THE INACTIVE RWY (MY UNDERSTANDING). WE TAXIED TO THE RWY AND I ADVANCED THROTTLES PAST 33% (TO ACTIVATE THE TKOF WARNING SYS) WITH PARK BRAKE RELEASED. I TAXIED FOR A SHORT TIME TO SEE IF THE FAULT WOULD OCCUR WITH THE THROTTLES ADVANCED. NO WARNING HORN. I RETURNED THROTTLES TO IDLE AND STARTED BRAKING ACTION. I WAS NOT ABLE TO MAKE THE TXWY E TURNOFF AND DEPLOYED THRUST REVERSERS TO STOP AS QUICKLY AS I COULD. I WAS NOT AWARE THAT THE ACTIVE RWY WAS THE NEXT INTXN. WHEN THE ACFT WAS STOPPED IT WAS APPROX 1/2 AIRPLANE OVER THE HOLD SHORT LINE.

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.