RPTR ALLEGES THE MEXICAN CTR DSNDED HIS ACFT IN CONFLICT WITH A CLBING ACFT AND WAS FACED WITH PROVIDING HIS OWN SEPARATION BY TURNING.

Narrative

WHILE ON A DSCNT INTO ELP FOR A CUSTOMS STOP WE WERE IN MEXICAN AIRSPACE BEING CTLED BY JUAREZ CTL. A TFC CONFLICT OCCURRED ABOUT 10 NM S OF CJS VOR. APPROX 20 NM S OF CJS; JUAREZ CTL ASKED FOR A GOOD RATE OF DSCNT DOWN TO 110000 FT. AT THIS POINT WE WERE APPROX DSNDING THROUGH FL200. I BELIEVED THAT WE WERE IN RADAR CONTACT AT THIS POINT. A MOMENT LATER JUAREZ STARTED ASKING US FOR OUR RADIAL AND DME FROM CJS AND THEN STARTED GIVING US INFO (RADIAL) ON A MEXICAN AIRLINER FROM CJS. AT THIS TIME I LOOKED DOWN AT MY NAV DISPLAY TO SEE TFC 3500 FT BELOW OUR ALT AND CLBING ON THE TCASII. SINCE I WAS DSNDING AT 3500 FPM (ATC ASKED FOR GOOD RATE) AND WE WERE TOLD TFC WAS CLBING TO 16000 FT MY INSTINCT TOOK OVER AND I TURNED THE ACFT IMMEDIATELY TO THE R. APPROX 20-30 SECONDS LATER WE MADE VISUAL CONTACT WITH THE AIRLINER CLBING THROUGH OUR ALT APPROX 1-2 NM AWAY. AS I LOOK BACK ON THIS OCCURRENCE I REALIZE THAT LIMITING MY RATE OF DSCNT WHILE TURNING THE ACFT WOULD HAVE GIVEN US THE MOST TIME TO LOCATE THE TFC. THE ROOT CAUSE OF THIS SIT SEEMS TO BE; RADAR CONTACT OR NOT; A BLATANT VIOLATION OF ACFT SEPARATION BY ATC. MY COPLT SAID AFTER THE OCCURRENCE THAT THIS WAS COMMON PRACTICE BY CTLRS DOWN S NOT WANTING TO TURN A NATIONAL AIRLINER. I HOPE THIS IS NOT THE CASE. THERE SEEMS TO BE MORE TO THE PROB THAN JUST TURNING AN ACFT.