Narrative:

I was pilot monitoring on the ILS prm runway 10 at ZZZ; in visual conditions. The weather at night was overcast at 7-8000 ft with visibility at better than 10 miles and moderate turbulence and strong sse winds at approach altitude. We had been cleared to turn to 360 and descend to 3500 ft. Shortly after; we were given a heading of 070 to intercept the runway 10 localizer and asked to call the airport in sight. The first officer was flying the aircraft with the autopilot engaged. The approach was properly set up; tuned and identified with LNAV/localizer and glideslope showing armed on both pfd's. The controller was very busy and asked if we could accept a visual to runway 10. I clearly could see all the south runways and accepted the visual. As we approached the localizer; I announced localizer alive as the course indicator began to move. The aircraft continued on the 070 heading; flew through the localizer; and did not intercept on either primary flight display (pfd). I immediately selected a turn to the southeast using heading select but due to the strong winds flew past the localizer enough that the controller queried as to whether or not we had runway 10 in sight and that there was an aircraft above us going to runway 9R. He did not issue any breakout instructions. I did not see the the other aircraft either visually or on TCAS. I told the controller that we had overshot but were correcting back to the localizer. As we flew back to re-intercept I reset both FD switches to reengage the approach. Again the localizer did not capture but we used heading select to manually intercept. I told the first officer to just use raw data to fly the approach but then noticed that his FD command bars and raw data indications were flashing offirst officern intermittently. We continued the approach visually and landed without delay. I later talked on the phone with the approach control supervisor who told me there was not a conflict and that the other aircraft was 1900 ft above our altitude where the controller made the call to us. He replayed the tape and said that he could clearly see us make the turn back to the southeast after the overshoot. I explained what had happened in the cockpit and he said there was no problem. I wrote up the discrepancy after landing and took the same airplane the next morning. That night maintenance had performed bite checks; found no faults; and performed a land verification check on the fmcs and signed off the write-up. During the visual approach the next morning; the same malfunction recurred on the ILS runway 9. This time maintenance was able to determine that the right multimode receiver (mmr) was at fault and replaced it. I have never experienced this type of failure in 5 years on the 737-800. Everything was set properly and certainly appeared to operate normally until the most critical time. I should have noticed that the localizer capture indication normally occurs just prior to actual capture and could have intervened earlier to lesson the overshoot.

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Original NASA ASRS Text

Title: a B737-800's Multimode Receiver faulted preventing the aircraft from capturing a localizer.

Narrative: I was pilot monitoring on the ILS PRM Runway 10 at ZZZ; in visual conditions. The weather at night was overcast at 7-8000 FT with visibility at better than 10 miles and moderate turbulence and strong SSE winds at approach altitude. We had been cleared to turn to 360 and descend to 3500 FT. Shortly after; we were given a heading of 070 to intercept the Runway 10 localizer and asked to call the airport in sight. The First Officer was flying the aircraft with the autopilot engaged. The approach was properly set up; tuned and identified with LNAV/Localizer and glideslope showing armed on both PFD's. The Controller was very busy and asked if we could accept a visual to Runway 10. I clearly could see all the south runways and accepted the visual. As we approached the localizer; I announced localizer alive as the course indicator began to move. The aircraft continued on the 070 heading; flew through the localizer; and did not intercept on either Primary Flight Display (PFD). I immediately selected a turn to the SE using heading select but due to the strong winds flew past the localizer enough that the Controller queried as to whether or not we had Runway 10 in sight and that there was an aircraft above us going to Runway 9R. He did not issue any breakout instructions. I did not see the the other aircraft either visually or on TCAS. I told the Controller that we had overshot but were correcting back to the localizer. As we flew back to re-intercept I reset both FD switches to reengage the approach. Again the localizer did not capture but we used heading select to manually intercept. I told the First Officer to just use raw data to fly the approach but then noticed that his FD command bars and raw data indications were flashing OFF/ON intermittently. We continued the approach visually and landed without delay. I later talked on the phone with the Approach Control Supervisor who told me there was not a conflict and that the other aircraft was 1900 FT above our altitude where the Controller made the call to us. He replayed the tape and said that he could clearly see us make the turn back to the southeast after the overshoot. I explained what had happened in the cockpit and he said there was no problem. I wrote up the discrepancy after landing and took the same airplane the next morning. That night Maintenance had performed bite checks; found no faults; and performed a land verification check on the FMCS and signed off the write-up. During the visual approach the next morning; the same malfunction recurred on the ILS Runway 9. This time maintenance was able to determine that the right multimode receiver (MMR) was at fault and replaced it. I have never experienced this type of failure in 5 years on the 737-800. Everything was set properly and certainly appeared to operate normally until the most critical time. I should have noticed that the localizer capture indication normally occurs just prior to actual capture and could have intervened earlier to lesson the overshoot.

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.