Narrative:

B190 was cleared for takeoff on runway 6L while on taxiway Y, just crossing taxiway left. Was distraction by conversations in the tower cabin attendant when the DH8 called for crossing. Had forgotten about the B190 cleared for takeoff on runway 6L and crossed the DH8. I looked back to scan the runway when I realized that the B190 was pulling onto the runway (rolling takeoff) and the DH8 was crossing runway 6L. I cancelled the B190's takeoff clearance as he was passing the intersection of runway 32 on runway 6L. I instructed the B190 to back taxi on runway 6L to depart again. B190 departed without further incident, comment or complaint. The DH8 pilot never said anything. Aug/fri/04, chief pilot for the DH8 operator called reference the incident. Air traffic manager starting an operational error investigation. I believe I avoided an error by catching the situation and canceling the B190's takeoff clearance. Neither pilot questioned clrncs or complained, I therefore believed that I had avoided a potential surface error. If an error was to have occurred why would neither pilot question the clrncs when both aircraft were in sight of each other? The potential was there, most definitely, but I believe it was no factor with the cancellation of clearance. Supplemental information from acn 628459: tower immediately gave clearance to cross runways 6L and 6R via taxiway D to parking. Taxi clearance was repeated back to ATC. Initial visual clearing of the runway showed no visible traffic on approach or on the runway. A second visual clearing of the runway was made as we crossed the runway, and another aircraft was observed on the runway. I made a call to captain stating that there was another aircraft on the runway. We expedited off the runway and continued to parking. At that moment the tower cancelled the other aircraft takeoff clearance (no takeoff clearance had been heard prior to initial contact with tower). ATC made no contact with us to give us corrective action, as we cleared the runway and taxied to parking. Shortly after we overheard the tower apologize to the other aircraft.

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Original NASA ASRS Text

Title: ANC LCL CTLR EXPERIENCED CONFLICT WHEN XING TAXIING ACFT IN FRONT OF DEPARTING ACFT REQUIRING ISSUANCE OF ABORT CLRNC.

Narrative: B190 WAS CLRED FOR TKOF ON RWY 6L WHILE ON TXWY Y, JUST XING TXWY L. WAS DISTR BY CONVERSATIONS IN THE TWR CAB WHEN THE DH8 CALLED FOR XING. HAD FORGOTTEN ABOUT THE B190 CLRED FOR TKOF ON RWY 6L AND CROSSED THE DH8. I LOOKED BACK TO SCAN THE RWY WHEN I REALIZED THAT THE B190 WAS PULLING ONTO THE RWY (ROLLING TKOF) AND THE DH8 WAS XING RWY 6L. I CANCELLED THE B190'S TKOF CLRNC AS HE WAS PASSING THE INTXN OF RWY 32 ON RWY 6L. I INSTRUCTED THE B190 TO BACK TAXI ON RWY 6L TO DEPART AGAIN. B190 DEPARTED WITHOUT FURTHER INCIDENT, COMMENT OR COMPLAINT. THE DH8 PLT NEVER SAID ANYTHING. AUG/FRI/04, CHIEF PLT FOR THE DH8 OPERATOR CALLED REF THE INCIDENT. AIR TFC MGR STARTING AN OPERROR INVESTIGATION. I BELIEVE I AVOIDED AN ERROR BY CATCHING THE SIT AND CANCELING THE B190'S TKOF CLRNC. NEITHER PLT QUESTIONED CLRNCS OR COMPLAINED, I THEREFORE BELIEVED THAT I HAD AVOIDED A POTENTIAL SURFACE ERROR. IF AN ERROR WAS TO HAVE OCCURRED WHY WOULD NEITHER PLT QUESTION THE CLRNCS WHEN BOTH ACFT WERE IN SIGHT OF EACH OTHER? THE POTENTIAL WAS THERE, MOST DEFINITELY, BUT I BELIEVE IT WAS NO FACTOR WITH THE CANCELLATION OF CLRNC. SUPPLEMENTAL INFO FROM ACN 628459: TWR IMMEDIATELY GAVE CLRNC TO CROSS RWYS 6L AND 6R VIA TXWY D TO PARKING. TAXI CLRNC WAS REPEATED BACK TO ATC. INITIAL VISUAL CLRING OF THE RWY SHOWED NO VISIBLE TFC ON APCH OR ON THE RWY. A SECOND VISUAL CLRING OF THE RWY WAS MADE AS WE CROSSED THE RWY, AND ANOTHER ACFT WAS OBSERVED ON THE RWY. I MADE A CALL TO CAPT STATING THAT THERE WAS ANOTHER ACFT ON THE RWY. WE EXPEDITED OFF THE RWY AND CONTINUED TO PARKING. AT THAT MOMENT THE TWR CANCELLED THE OTHER ACFT TKOF CLRNC (NO TKOF CLRNC HAD BEEN HEARD PRIOR TO INITIAL CONTACT WITH TWR). ATC MADE NO CONTACT WITH US TO GIVE US CORRECTIVE ACTION, AS WE CLRED THE RWY AND TAXIED TO PARKING. SHORTLY AFTER WE OVERHEARD THE TWR APOLOGIZE TO THE OTHER ACFT.

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.