MD80 CREW HAD NMAC WITH A MIL HELI WHILE ON FINAL AT A FOREIGN ARPT.

Narrative

I FIRST SAW THE HELI LIFTING OFF WHEN HE WAS ABOUT 4000 FT IN FRONT OF US. HIS HDG WAS APPROX 340 DEGS DIRECTLY ACROSS OUR PATH. IN APPROX 2 SECONDS THE HELI HAD CROSSED THE RWY 5R. HE THEN MADE A HARD L TURN BACK ACROSS THE RWY DIRECTLY IN OUR PATH. WE LEVELED OFF AT APPROX 300 FT. HE WAS CLBING VERY FAST ALMOST DIRECTLY AT US. WE STARTED A TURN TO THE L. HE SAW US AND TURNED HARD L. WE MADE A SLIGHT TURN BACK TO THE RWY AND LANDED. THE HELI PASSED 200 FT TO OUR R AND 100 FT BELOW US. MEXICO CITY ARPT ELEVATION IS 7341 FT. WE WERE AT OUR MAX LNDG WT; BY TRYING TO GO AROUND THE ACFT WOULD SINK AND OUR NOSE WOULD HAVE BEEN HIGH. WE WOULD HAVE LOST SIGHT OF THE HELI. BY JUST LEVELING OFF WE HAD THE OPTION OF GOING L OR R TO MISS THE TFC IF HE HAD NOT SEEN US. ALL OUR LIGHTS WERE ON AND I BELIEVE THAT'S WHAT THE HELI PLT SAW FIRST. IF THE MEXICAN CTLRS WOULD SPEAK ENGLISH TO EVERYONE; WE MAY HAVE BEEN ABLE TO HEAR THE CLRNC GIVEN TO THE HELI TO DEPART. ENGLISH SPEAKING CREWS ONLY HEAR THE CLRNCS GIVEN TO THEM. PROBS COULD BE AVOIDED IF ALL OF US WERE ON THE SAME PAGE. SPANISH AND ENGLISH DON'T MIX IN AVIATION. 'ENGLISH ONLY.'