Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Air Traffic Control Issued New Clearance; Flight Crew Executed Go Around / Missed Approach; Flight Crew Requested ATC Assistance / Clarification
Human Factors; Environment - Non Weather Related; Aircraft
Taking an air carrier with GPS into MMMX- weather lousy; we were a few minutes from diverting in the hold north of SLM.  We knew about the GPS problems after SMO for the ILS 05R- we had the First Officer (pilot flying) set to intercept the SMO 168R outbound; I had the MEX radial setup for the lead turn to the ILS.  We agreed that he would intercept the SMO radial and once tracking; go to heading hold and I would change his radio to the ILS; and he would turn onto the ILS course after my radial was crossed.  The GPS went into DR about 8 DME from SMO; well before the other time I had landed on this runway.  SMO was working well until we crossed the VOR and received a VOR fail.  We went ahead and turned to a 168 heading to allow the VOR to return.  Unknown to me; even though I had stated several times that the GPS was in DR and not reliable; the First Officer decided to use that display and we got off course with the radial turn.  Approach didn't like the turn-on to the ILS and sent us around.  Since we were very short on fuel; I was able to talk Approach into vectoring us back for the approach again; and this time with vectors onto the ILS.  The GPS was in DR for all of this time.  The second approach was successful.  After landing; the GPS returned to normal during taxi in.
Air Carrier Captain experiences GPS failure approaching SMO on the approach to Runway 5R at MMMX; which had been expected due to previous experience. The plan for executing the approach with radio navigation only is not followed faithfully resulting in an ATC commanded go-around. The second approach is successful. Holding for weather caused a low fuel situation.