Narrative:

Depart mex on given departure route, captain inquired as to why we were not given departure/en route clearance as filed. Confusion followed and then mex ATC (126.6) gave us a heading to intercept the filed route. This caused us to fly across the well known arrival route. While climbing out at 32000 for 35000 we received a 'traffic, traffic' alert from TCASII, followed by a nervous mex ATC controller command to turn left to 270 heading. I disengaged the autoplt and manual commenced a turn to the left while trying to continue the climb. The TCASII then gave a 'climb' report and indicated a rate of 2000 FPM on the ivsi (green arc). An large transport was descending toward us, approximately 10 degrees right of our relative position. I heard the large transport given a command to 'expedite their descent and turn...'. My medium large transport did not climb after commencing a turn to the left (approximately bank was 30-45 degrees at 32500). I fault myself in many areas. TCASII was set to 20 mi range when 40 was available. I should have left aircraft on autoplt and continued climb as the TCASII directed and used only a 30 degree bank for mex ATC directed left turn. Strongly recommend that arrival/departure traffic did not cross each other in areas of questionable radar and controllers. Had we continued the given departure routing this would not have happened.

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Original NASA ASRS Text

Title: LTSS BTWN ACR MLG IN CLB OUT FROM MEX AND ACR LGT ON DSCNT INTO MEX.

Narrative: DEPART MEX ON GIVEN DEP RTE, CAPT INQUIRED AS TO WHY WE WERE NOT GIVEN DEP/ENRTE CLRNC AS FILED. CONFUSION FOLLOWED AND THEN MEX ATC (126.6) GAVE US A HDG TO INTERCEPT THE FILED RTE. THIS CAUSED US TO FLY ACROSS THE WELL KNOWN ARR RTE. WHILE CLBING OUT AT 32000 FOR 35000 WE RECEIVED A 'TFC, TFC' ALERT FROM TCASII, FOLLOWED BY A NERVOUS MEX ATC CTLR COMMAND TO TURN L TO 270 HDG. I DISENGAGED THE AUTOPLT AND MANUAL COMMENCED A TURN TO THE L WHILE TRYING TO CONTINUE THE CLB. THE TCASII THEN GAVE A 'CLB' RPT AND INDICATED A RATE OF 2000 FPM ON THE IVSI (GREEN ARC). AN LGT WAS DSNDING TOWARD US, APPROX 10 DEGS R OF OUR RELATIVE POS. I HEARD THE LGT GIVEN A COMMAND TO 'EXPEDITE THEIR DSCNT AND TURN...'. MY MLG DID NOT CLB AFTER COMMENCING A TURN TO THE L (APPROX BANK WAS 30-45 DEGS AT 32500). I FAULT MYSELF IN MANY AREAS. TCASII WAS SET TO 20 MI RANGE WHEN 40 WAS AVAILABLE. I SHOULD HAVE LEFT ACFT ON AUTOPLT AND CONTINUED CLB AS THE TCASII DIRECTED AND USED ONLY A 30 DEG BANK FOR MEX ATC DIRECTED L TURN. STRONGLY RECOMMEND THAT ARR/DEP TFC DID NOT CROSS EACH OTHER IN AREAS OF QUESTIONABLE RADAR AND CTLRS. HAD WE CONTINUED THE GIVEN DEP RTING THIS WOULD NOT HAVE HAPPENED.

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.