Narrative:

We were descending westbound on a visual approach and at about 10;000 ft approach informed us of traffic at our 12 o'clock; 4 miles; 4;400 ft; and traveling east. I exclaimed to the first officer that it couldn't be correct because at that position; the traffic would be just skimming the hills or underground because the terrain rises to the east to about 6;000 ft in that area. We started our scan and the first officer was first to spot the traffic at our 12 o'clock and about .5 miles opposite direction at about 9;500 ft as we were passing about 9;500 ft. I pushed slightly forward on the yoke to pass below the traffic as we were already in the descent. The cirrus passed off our left wing at approximately 100-200 ft to the left and 50-100 ft above our flight path. Total time of the encounter was about 7 seconds. The traffic then popped up on our TCAS as 4;400 ft and at no time did we receive a TA or RA. I believe that the conflicting traffic had a malfunctioning transponder that indicated 5;000 ft lower than actual altitude.

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Original NASA ASRS Text

Title: CRJ-200 Captain reported a NMAC with a light aircraft during a visual approach to PSP. Reporter believes the light aircraft transponder was malfunctioning; and no RA was received.

Narrative: We were descending westbound on a visual approach and at about 10;000 FT Approach informed us of traffic at our 12 o'clock; 4 miles; 4;400 FT; and traveling east. I exclaimed to the First Officer that it couldn't be correct because at that position; the traffic would be just skimming the hills or underground because the terrain rises to the east to about 6;000 FT in that area. We started our scan and the First Officer was first to spot the traffic at our 12 o'clock and about .5 miles opposite direction at about 9;500 FT as we were passing about 9;500 FT. I pushed slightly forward on the yoke to pass below the traffic as we were already in the descent. The Cirrus passed off our left wing at approximately 100-200 FT to the left and 50-100 FT above our flight path. Total time of the encounter was about 7 seconds. The traffic then popped up on our TCAS as 4;400 FT and at no time did we receive a TA or RA. I believe that the conflicting traffic had a malfunctioning transponder that indicated 5;000 FT lower than actual altitude.

Data retrieved from NASA's ASRS site as of July 2013 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.