Narrative:

When towing aircraft X from blast fence to gate; moved from blast fence turn left onto taxiway '1.' when I started across taxiway '2;' I came off the gas and applied light brakes; the anti-skid started to cycle; speed was 12 mph. I came off the brakes to let the system reset. The anti-skid cycles became harder. When I saw we were not stopping I applied full hard brakes. As I entered onto the runway; I turned right to avoid the landing aircraft. After the aircraft had passed; I turned back onto taxiway '1.' the tug came to a stop after crossing runway xxr. Tug brake system failed. Supplemental information from acn 782353: while riding radios; delivering aircraft X with tug; mr X and myself were cleared up to and hold short of runway xxl. Upon the aircraft clearing the center of taxiway '2' the aircraft seemed to start pushing the tug. Mr X started to apply the brakes and the tug lurched and started bouncing. The more he tried to stop; the more severe the bouncing got. We were pushed past the hold short line and into the runway area. There was an MD80 landing at this time. The tug is equipped with 'anti-skid.' this system did not appear to function properly. Inspect tug braking system.

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Original NASA ASRS Text

Title: TWO MECHANICS; ONE TOWING AND THE OTHER IN THE COCKPIT; DESCRIBE THEIR SITUATION WHEN THEIR TUG ANTI-SKID BRAKES FAILED TO STOP THEIR B777 ACFT AS THEY APPROACHED AN ACTIVE RUNWAY WITH AN MD80 LANDING.

Narrative: WHEN TOWING ACFT X FROM BLAST FENCE TO GATE; MOVED FROM BLAST FENCE TURN L ONTO TXWY '1.' WHEN I STARTED ACROSS TXWY '2;' I CAME OFF THE GAS AND APPLIED LIGHT BRAKES; THE ANTI-SKID STARTED TO CYCLE; SPD WAS 12 MPH. I CAME OFF THE BRAKES TO LET THE SYS RESET. THE ANTI-SKID CYCLES BECAME HARDER. WHEN I SAW WE WERE NOT STOPPING I APPLIED FULL HARD BRAKES. AS I ENTERED ONTO THE RWY; I TURNED R TO AVOID THE LNDG ACFT. AFTER THE ACFT HAD PASSED; I TURNED BACK ONTO TXWY '1.' THE TUG CAME TO A STOP AFTER XING RWY XXR. TUG BRAKE SYS FAILED. SUPPLEMENTAL INFO FROM ACN 782353: WHILE RIDING RADIOS; DELIVERING ACFT X WITH TUG; MR X AND MYSELF WERE CLRED UP TO AND HOLD SHORT OF RWY XXL. UPON THE ACFT CLRING THE CTR OF TXWY '2' THE ACFT SEEMED TO START PUSHING THE TUG. MR X STARTED TO APPLY THE BRAKES AND THE TUG LURCHED AND STARTED BOUNCING. THE MORE HE TRIED TO STOP; THE MORE SEVERE THE BOUNCING GOT. WE WERE PUSHED PAST THE HOLD SHORT LINE AND INTO THE RWY AREA. THERE WAS AN MD80 LNDG AT THIS TIME. THE TUG IS EQUIPPED WITH 'ANTI-SKID.' THIS SYS DID NOT APPEAR TO FUNCTION PROPERLY. INSPECT TUG BRAKING SYS.

Data retrieved from NASA's ASRS site as of May 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.