Narrative:

After clearing runway 30R at stl on the high speed taxiway, the first officer made a call to ground and reported same. The ground controller replied with 'air carrier X taxi to the ramp.' we proceeded to taxi up to runway 30L, at which time the first officer reported 'clear right.' I reported, '1 aircraft in position on the left.' continuing the taxi across the hold short line, I then realized that the aircraft was moving and applied the brakes. I stopped the aircraft approximately 15 ft from the white runway line. The B727 took off without incident. Verification of taxi clearance to cross runway 30L would have prevented the problem.

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Original NASA ASRS Text

Title: BA32 FLC CROSSES RWY HOLD LINE AT STL.

Narrative: AFTER CLRING RWY 30R AT STL ON THE HIGH SPD TXWY, THE FO MADE A CALL TO GND AND RPTED SAME. THE GND CTLR REPLIED WITH 'ACR X TAXI TO THE RAMP.' WE PROCEEDED TO TAXI UP TO RWY 30L, AT WHICH TIME THE FO RPTED 'CLR R.' I RPTED, '1 ACFT IN POS ON THE L.' CONTINUING THE TAXI ACROSS THE HOLD SHORT LINE, I THEN REALIZED THAT THE ACFT WAS MOVING AND APPLIED THE BRAKES. I STOPPED THE ACFT APPROX 15 FT FROM THE WHITE RWY LINE. THE B727 TOOK OFF WITHOUT INCIDENT. VERIFICATION OF TAXI CLRNC TO CROSS RWY 30L WOULD HAVE PREVENTED THE PROB.

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.