Narrative:

Aircraft was set up for a visual approach backed up by the ILS 34R into slc with an expected sidestep to runway 35. ILS 34R was loaded into FMS as per company policy for a backup. Checklist was completed and weather was VFR at airport and an expected visual approach to runway 35. On or near IAF crew was taken off the ffu transition and radar vectored across localizer then turned back to 310 degrees to rejoin localizer and cleared for the approach. FMS was 'cleaned up' and an extended centerline was introduced in the FMS as per company procedures. This 'cleanup' process de-clutters approaches by eliminating unnecessary waypoints; usually retaining 1 or 2 waypoints prior to FAF. So we had scoer and atane in FMS. Aircraft was joining up inbound course and descent began for atane at 10;000 ft. Subsequently; we were instructed to cross plage at 10;200 ft; which we complied using DME. Simultaneously to joining up for inbound course avionics anomalies began and PF disconnected autopilot and hand flew rest of approach. Crew felt they did not have reliable navigational information and elected to obtain radar vectors for another approach. This was given and a successful approach and landing was made to ILS 34L. Approaching ramp ground control advised us to contact local FSDO with a telephone number; which we did. Human performance considerations: crew workload was high with numerous airspeed; altitude; and heading changes coupled with a 14 hour duty day; 9 hours of flying with minimum rest previous day. I believe pilot fatigue was a factor. Crew feels they broke the chain of events that could have led to a more serious event.

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Original NASA ASRS Text

Title: P180 First Officer describes a missed approach at SLC after being vectored across the LOC by ATC and experiencing avionics anomalies. Crew descended early after being cleared for the approach and did not comply with a step down altitude.

Narrative: Aircraft was set up for a visual approach backed up by the ILS 34R into SLC with an expected sidestep to Runway 35. ILS 34R was loaded into FMS as per company policy for a backup. Checklist was completed and weather was VFR at airport and an expected visual approach to Runway 35. On or near IAF crew was taken off the FFU transition and radar vectored across localizer then turned back to 310 degrees to rejoin localizer and cleared for the approach. FMS was 'cleaned up' and an extended centerline was introduced in the FMS as per company procedures. This 'cleanup' process de-clutters approaches by eliminating unnecessary waypoints; usually retaining 1 or 2 waypoints prior to FAF. So we had SCOER and ATANE in FMS. Aircraft was joining up inbound course and descent began for ATANE at 10;000 FT. Subsequently; we were instructed to cross PLAGE at 10;200 FT; which we complied using DME. Simultaneously to joining up for inbound course avionics anomalies began and PF disconnected autopilot and hand flew rest of approach. Crew felt they did not have reliable navigational information and elected to obtain radar vectors for another approach. This was given and a successful approach and landing was made to ILS 34L. Approaching ramp ground control advised us to contact local FSDO with a telephone number; which we did. Human Performance Considerations: Crew workload was high with numerous airspeed; altitude; and heading changes coupled with a 14 hour duty day; 9 hours of flying with minimum rest previous day. I believe pilot fatigue was a factor. Crew feels they broke the chain of events that could have led to a more serious event.

Data retrieved from NASA's ASRS site as of April 2012 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.