Narrative:

We were shooting an RNAV approach. The ceilings were 4000 feet overcast the entire area with multiple layers to 2000 feet in the vicinity of the approach. TRACON aborted our first approach while IMC due to traffic loitering in the final approach path. This was also shown on our traffic display. On our second approach; TRACON switched us to CTAF as soon as we intercepted the glidepath since the traffic appeared to be moving away and encouraged us to make contact with the traffic. Unfortunately; multiple position reports on CTAF generated no response. After passing the final approach fix; our traffic display indicated that the traffic had reversed course. Now we were IMC and below TRACON radio reception altitude. Since we were beginning to see the ground; I dipped 200 feet below the glidepath and broke out at 2000 feet with the conflicting traffic at our altitude skimming the overcast layer at 11 o'clock off our left wing; initiating a turn back across the final approach path. Now VMC; we deviated north; accelerated our descent; attempted unsuccessfully to make radio contact; and landed. In retrospect; when the traffic reversed course we should have aborted the approach again. But without our traffic display; we would have had a very close miss or worse.the root issue is an aircraft ignoring VFR flight restrictions and not being on CTAF. Unfortunately; this is a common issue in the vicinity of this airport. Contributing factors include very poor radar and radio coverage directly adjacent to the class B surface area. Ads-B will presumably help with radar coverage problems. But I wish that TRACON actually used and monitored a frequency for approaches into the airport. From speaking with TRACON they have a frequency that works fine but apparently is connected to the 'wrong' desk. This should be fixed.

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Original NASA ASRS Text

Title: DA40 pilot reported a near miss with a VFR aircraft not on CTAF frequency while conducting an RNAV approach to HAF airport.

Narrative: We were shooting an RNAV approach. The ceilings were 4000 feet overcast the entire area with multiple layers to 2000 feet in the vicinity of the approach. TRACON aborted our first approach while IMC due to traffic loitering in the final approach path. This was also shown on our traffic display. On our second approach; TRACON switched us to CTAF as soon as we intercepted the glidepath since the traffic appeared to be moving away and encouraged us to make contact with the traffic. Unfortunately; multiple position reports on CTAF generated no response. After passing the Final Approach fix; our traffic display indicated that the traffic had reversed course. Now we were IMC and below TRACON radio reception altitude. Since we were beginning to see the ground; I dipped 200 feet below the glidepath and broke out at 2000 feet with the conflicting traffic at our altitude skimming the overcast layer at 11 o'clock off our left wing; initiating a turn back across the final approach path. Now VMC; we deviated north; accelerated our descent; attempted unsuccessfully to make radio contact; and landed. In retrospect; when the traffic reversed course we should have aborted the approach again. But without our traffic display; we would have had a very close miss or worse.The root issue is an aircraft ignoring VFR flight restrictions and not being on CTAF. Unfortunately; this is a common issue in the vicinity of this airport. Contributing factors include very poor radar and radio coverage directly adjacent to the Class B surface area. ADS-B will presumably help with radar coverage problems. But I wish that TRACON actually used and monitored a frequency for approaches into the airport. From speaking with TRACON they have a frequency that works fine but apparently is connected to the 'wrong' desk. This should be fixed.

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.