Narrative:

While descending on the AVSAR2A arrival into mexico city MMMX; we were cleared to descend to 12;000 feet MSL and direct to the mateo VOR (smo). Subsequently we received clearance to fly the RNAV (GPS) or ILS rwy 5. The autopilot was engaged and LNAV and VNAV were selected and operating. Upon reaching smo the aircraft continued straight through the fix without turning to fly the course out of mavek IAF which overlies smo VOR. Apparently there is a discontinuity there of which I was unaware at that moment. I went to heading select to begin turning back to our expected routing when mexico city approach called and gave us vectors back to intercept then ILS rwy 5R.checking for a discontinuity on the legs page would have avoided the problem.

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Original NASA ASRS Text

Title: Inbound to MMMX on the AVSAR2A arrival a B737 crew was cleared direct to SMO VOR; cleared the RNAV (GPS) or ILS Rwy 5R approach. Upon passing SMO the jet continued straight ahead instead of turning toward the approach.

Narrative: While descending on the AVSAR2A arrival into Mexico City MMMX; we were cleared to descend to 12;000 feet MSL and direct to the Mateo VOR (SMO). Subsequently we received clearance to fly the RNAV (GPS) or ILS Rwy 5. The autopilot was engaged and LNAV and VNAV were selected and operating. Upon reaching SMO the aircraft continued straight through the fix without turning to fly the course out of MAVEK IAF which overlies SMO VOR. Apparently there is a discontinuity there of which I was unaware at that moment. I went to heading select to begin turning back to our expected routing when Mexico City Approach called and gave us vectors back to intercept then ILS Rwy 5R.Checking for a discontinuity on the legs page would have avoided the problem.

Data retrieved from NASA's ASRS site 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.