A320
Flight Crew Air Transport Pilot (ATP)
Flight Crew Type 607
Communication Breakdown; Situational Awareness
ATC Issue All Types
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Human Factors
Doing the arrival into MMMX (Mexico City) at dusk in the rain. Conditions are not terrible; really don't impact this problem. Told to descend via the AVSAR1C arrival; and both the FO and I are pleasantly surprised that the usual nonsense of turning to multiple headings and intercepting multiple radials isn't happening. We get a straight descent via the arrival until we are only 3 miles from Santa Lucia (SLM). As usual in MMMX; the radio frequency is very congested; with very lengthy conversations in Spanish between pilots and controllers; multiple pilots stepping on each others transmissions; etc. There is no way for us to speak with ATC; luckily we don't need to as all is going well. Then just three miles from SLM; we hear the controller say 'turn to a heading of 220 degrees; intercept the Mateo 320 radial inbound; cleared for the ILS 5R approach; slow to 210 knots.' We query him to confirm the radial; heading and speed again; then he's off and gone in another lengthy conversation in Spanish. All this happens at the very last moment; and while the FO is flying; I am left leafing through multiple pages on the iPad looking for somewhere that the Mateo identifier is listed. It can't be found. I know it's co-located with Mavek; but none of the charts we are using; (STAR; ILS 5R approach) show Mateo; they all show Mavek. This is an extremely uncomfortable situation; looking through charts for a missing identifier while flying blindly through MMEX arrival airspace; hoping that you haven't already blasted through the assigned radial that was supposed to have been intercepted. Finally; I find the identifier for Mateo (SMO) buried among much tiny text on the 11-0A plate.
A320 Captain reported concern about a possible track deviation when he had difficulty finding the identifier for Mateo while on approach to MMMX.