Narrative:

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.

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Original NASA ASRS Text

Title: 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.

Narrative: 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.

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.