Narrative:

Foreign air carrier flight Y, a boeing 727, was cleared for takeoff, runway 23R. Several mins later we were cleared for takeoff, runway 23L. The pinos 2 departure requires a left turn at (mw) to join the departure. We were unaware Y was supposed to be flying the same departure. It appeared to us he overflew the departure and was flying the mevil one departure. We lost sight of aircraft Y because of the sun in our eyes. We started our turn at mw on time and speed. As we continued our turn sbound aircraft Y came into view. Since our climb rate was higher and speed slower we actually turned inside Y who appeared to be making a very wide and shallow turn. I asked that departure controller if Y was flying the same departure. Due to the controller's use of spanish and then switching to english, I was not able to understand his first transmission. About the time I was trying to ask again, we got the TCASII RA to descend which we did and no further action was required. The controller then provided heading and altitude to rejoin the departure. Probable causes: sun in eyes for takeoff and departure, mexican controllers continuous use of spanish when speaking with local carriers. English speaking crews never know what they are saying, language barrier and different aircraft performance between B737 and B727.

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Original NASA ASRS Text

Title: A B737-300 DEPARTING MEXICO CITY HAS A POTENTIAL CONFLICT WITH A FOREIGN ACR ON THE SAME DEP PROC. THE PRECEDING B727 HAD MADE A DELAYED, WIDER TURN AT THE DEP FIX WHICH BROUGHT THE 2 ACFT CLOSER THAN ATC HAD PLANNED.

Narrative: FOREIGN ACR FLT Y, A BOEING 727, WAS CLRED FOR TKOF, RWY 23R. SEVERAL MINS LATER WE WERE CLRED FOR TKOF, RWY 23L. THE PINOS 2 DEP REQUIRES A L TURN AT (MW) TO JOIN THE DEP. WE WERE UNAWARE Y WAS SUPPOSED TO BE FLYING THE SAME DEP. IT APPEARED TO US HE OVERFLEW THE DEP AND WAS FLYING THE MEVIL ONE DEP. WE LOST SIGHT OF ACFT Y BECAUSE OF THE SUN IN OUR EYES. WE STARTED OUR TURN AT MW ON TIME AND SPD. AS WE CONTINUED OUR TURN SBOUND ACFT Y CAME INTO VIEW. SINCE OUR CLB RATE WAS HIGHER AND SPD SLOWER WE ACTUALLY TURNED INSIDE Y WHO APPEARED TO BE MAKING A VERY WIDE AND SHALLOW TURN. I ASKED THAT DEP CTLR IF Y WAS FLYING THE SAME DEP. DUE TO THE CTLR'S USE OF SPANISH AND THEN SWITCHING TO ENGLISH, I WAS NOT ABLE TO UNDERSTAND HIS FIRST XMISSION. ABOUT THE TIME I WAS TRYING TO ASK AGAIN, WE GOT THE TCASII RA TO DSND WHICH WE DID AND NO FURTHER ACTION WAS REQUIRED. THE CTLR THEN PROVIDED HEADING AND ALT TO REJOIN THE DEP. PROBABLE CAUSES: SUN IN EYES FOR TKOF AND DEP, MEXICAN CTLRS CONTINUOUS USE OF SPANISH WHEN SPEAKING WITH LCL CARRIERS. ENGLISH SPEAKING CREWS NEVER KNOW WHAT THEY ARE SAYING, LANGUAGE BARRIER AND DIFFERENT ACFT PERFORMANCE BTWN B737 AND B727.

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.