Flight Crew Air Transport Pilot (ATP)
Confusion; Human-Machine Interface; Situational Awareness
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert
Aircraft; Human Factors; Procedure; Chart Or Publication
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.
MATEO and MAVEK are the same point in space; but they have different names. This leads to confusion.MAVEK is only depicted on the RNAV GPS approach; it is not depicted on the ILS DME RWY 05R. Approach uses both terms interchangeably. The first time I was going into MMMX; I was planning to fly the ILS and did not look at the RNAV approach. I was cleared to MAVEK; but had no idea where it was since it was not depicted on the AVSAR STAR or the ILS approach plate. This is confusing; especially with the language barrier.What makes the situation worse; is that if you are direct to Mateo and then cleared to the RNAV approach; the auto pilot has a discontinuity; gets confused and disengages. You have to be going direct to Mavek; not MATEO; for the RNAV approach to work.Change the approach procedures at MMMX so that there is only one name for the point in space known as MAVEK and [SMO].
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.