ACR CLRED TO CROSS RWY AFTER LNDG HAS LGT ON TKOF PASS DIRECTLY IN FRONT OF ACFT.

Narrative

DURING LNDG ROLLOUT FOLLOWING A ROUTINE ILS APCH AND LNDG ON RWY 5R AT MEXICO CITY INTL ARPT; WE WERE CLRED BY TWR TO EXIT RWY 5R AT TAXIWAY 'E' (THE LAST HIGHSPD TAXIWAY FOR RWY 5R AND THE TAXIWAY WHICH CROSSES RWY 5L AT/NEAR ITS END); TO CROSS RWY 5L AND TO CONTACT GND CTL ON FREQ 122.4. AS WE CLRED RWY 5R AND BY VERBAL AGREEMENT; THE CAPT ASSUMED CTL OF ATC COMS (TWR) WHILE THE FO WENT OVER TO COMPANY FREQ FOR A GATE ASSIGNMENT. WE WERE TAXIING SLOWLY BTWN THE RWYS (ABOUT 10-15 KTS) AND ABOUT TO ENTER RWY 5L (THE NOSE OF OUR ACFT WAS ABOUT 10 FT FROM THE EDGE OF RWY 5L) WHEN AN ACR LGT PASSED DIRECTLY IN FRONT OF US AT HIGHSPD AND LOW ALT; JUST TAKING OFF. MISS DISTANCE WAS ABOUT 20-30 FT LATERALLY AND THE MAIN LNDG GEAR WHEELS OF THE LGT ACFT WERE ABOUT 10 FT OFF THE RWY AS IT PASSED IN FRONT OF US. (IT WAS A VERY LARGE LGT TO US). POST INCIDENT INTERVIEWS WITH THE TWR SUPVR; CTLRS AND VARIOUS COMPANY REPRESENTATIVES AS WELL AS MEXICAN ARPT AUTHORITIES REVEALED THAT LGT FLT HAD BEEN CLRED TO TKOF; IN SPANISH; PRIOR TO OUT BEING CLRED TO CROSS RWY 5L. WE WERE UNAWARE THAT AN ACFT HAD BEEN CLRED TO TKOF ON RWY 5L. THE LGT FLT WAS APPARENTLY UNAWARE THAT WE HAD BEEN CLRED TO CROSS RWY 5L. THE CONFLICT WENT UNNOTICED BY THE TWR CTLR AND HIS SUPVR UNTIL AFTER THE INCIDENT HAD OCCURRED. THE CAPT OF OUR ACFT WAS JUST IN THE PROCESS OF CLRING HIS L PRIOR TO ENTERING THE RWY AND COULD HAVE EXECUTED AN EMER STOP THUS AVOIDING A COLLISION HAD THE TIMING BEEN EVEN A LITTLE BIT DIFFERENT. MORAL OF THE STORY: YA'LL BE CAREFUL OUT THERE AND REMEMBER WHAT YOUR MAMA TOLD YOU WHEN YOU WERE A KID ABOUT XING THE STREETS.