Narrative:

While working local east on a runway 9 operation; I noticed a B757 approach runway 9L at taxiway north. The local west controller was issuing taxiing instructions to that aircraft to turn away from runway 9L and go south; not north on taxiway north. It appeared that the aircraft was not following instructions. I had already issued takeoff clearance to a CRJ2 on runway 9L. I immediately canceled his takeoff clearance and advised him to exit the runway at taxiway T. A few moments later the B757 aircraft crossed the runway. The amass alerted because the CRJ2 was still slowing down to exit at taxiway T. After a review of the voice recordings; the B757 pilot crossed the runway without ATC authority/authorized.

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Original NASA ASRS Text

Title: PHL LCL CTLR DESCRIBED GND CONFLICT WHEN ACR ENTERED RWY WITHOUT CLRNC; REQUIRING TKOF CLRNC CANCELLATION AND INITIATING AMASS ALERT.

Narrative: WHILE WORKING LCL E ON A RWY 9 OP; I NOTICED A B757 APCH RWY 9L AT TXWY N. THE LCL W CTLR WAS ISSUING TAXIING INSTRUCTIONS TO THAT ACFT TO TURN AWAY FROM RWY 9L AND GO S; NOT N ON TXWY N. IT APPEARED THAT THE ACFT WAS NOT FOLLOWING INSTRUCTIONS. I HAD ALREADY ISSUED TKOF CLRNC TO A CRJ2 ON RWY 9L. I IMMEDIATELY CANCELED HIS TKOF CLRNC AND ADVISED HIM TO EXIT THE RWY AT TXWY T. A FEW MOMENTS LATER THE B757 ACFT CROSSED THE RWY. THE AMASS ALERTED BECAUSE THE CRJ2 WAS STILL SLOWING DOWN TO EXIT AT TXWY T. AFTER A REVIEW OF THE VOICE RECORDINGS; THE B757 PLT CROSSED THE RWY WITHOUT ATC AUTH.

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.