A320
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 90; Flight Crew Type 7901
Situational Awareness
Aircraft Equipment Problem Less Severe
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Aircraft Equipment Problem Dissipated; Flight Crew Requested ATC Assistance / Clarification
ATC Equipment / Nav Facility / Buildings; Human Factors
We were enroute to EAGUL intersection at FL360 and had just briefed the EAGUL STAR and visual approach to PHX runway 8 when we overheard a couple of other flights noting anomalies with their GPS systems. These reports seemed to be connected with NOTAMs and RAIM notices about GPS outages near El Paso and Hector VORs. Then we began receiving ECAM for GPS2 FAULT and notices for loss and regain of GPS navigation. Nav accuracy seemed good; within 1 mile of known VOR locations. However; we noted persistent; random map shifts of up to 7 miles which lagged and was sometimes consistent with the cycling ECAM messages and notepad advisories. Rather than risk being unable to monitor an RNAV arrival; we chose to seek a less rigorous STAR at the suggestion of ATC. We were flying heading only; under ATC direction for about 10 minutes before they cleared us for the BUNTR STAR which we flew uneventfully. We monitored position and track with manual navigation radio and radial tuning. I looked for but could not find a checklist for the cycling malfunctions indicated by the GPS navigation loss notices in the MCDU scratchpad. We did the procedure anyway. The protocol to be directed to a checklist by a set condition fell short of certainty because of the random; sometimes rapid cycling of the notes themselves. We simply applied judgment that told us to confirm position accuracy and then involve ATC with awareness of our less than ideal navigational condition. There was also no time to coordinate more exotic solutions through dispatch because the descent was upon us by the time we received our new clearance.
A320 Captain experienced GPS signal interference and intermittent outages during arrival to PHX. The interference seemed to be connected with NOTAMs and RAIM (Receiver Autonomous Integrity Monitoring) notices about GPS outages near El Paso.