Narrative:

Arriving from the east into oma, we heard several calls to a light aircraft regarding his variations in altitude. There were 3 aircraft on our TCASII, 1 at 11 O'clock position and 2 at 2 O'clock position. 2 aircraft were at 4000 ft, and 1 was above our altitude -- I think. All aircraft were about 5 mi away when we first commented on the traffic in front of us, and approach gave us a slight vector away from the 11 O'clock traffic. He was supposed to be at 3500 ft, but TCASII showed him at 3800-4000 ft. At 2 mi, I commented that this was going to be close and told the captain I was turning further right to avoid the traffic. Soon after, we received the TA and almost immediately, received the RA. I climbed per the RA instructions and turned away from the location of the target. The last time I looked at the TCASII, his target had merged with our airplane symbol on the vsi, and it showed 200 ft below us. We reported the RA to approach and then contacted them upon arrival. Approach said he never got within 400 ft, but I know what I saw. We never visually acquired the target due to hazy -- sunset conditions.

Google
 

Original NASA ASRS Text

Title: MD80 CREW HAD A NMAC WITH A LIGHT ACFT IN OMA CLASS C, AFTER THE LIGHT ACFT PLT WAS NOT ABLE TO MAINTAIN HIS ASSIGNED ALT.

Narrative: ARRIVING FROM THE E INTO OMA, WE HEARD SEVERAL CALLS TO A LIGHT ACFT REGARDING HIS VARIATIONS IN ALT. THERE WERE 3 ACFT ON OUR TCASII, 1 AT 11 O'CLOCK POS AND 2 AT 2 O'CLOCK POS. 2 ACFT WERE AT 4000 FT, AND 1 WAS ABOVE OUR ALT -- I THINK. ALL ACFT WERE ABOUT 5 MI AWAY WHEN WE FIRST COMMENTED ON THE TFC IN FRONT OF US, AND APCH GAVE US A SLIGHT VECTOR AWAY FROM THE 11 O'CLOCK TFC. HE WAS SUPPOSED TO BE AT 3500 FT, BUT TCASII SHOWED HIM AT 3800-4000 FT. AT 2 MI, I COMMENTED THAT THIS WAS GOING TO BE CLOSE AND TOLD THE CAPT I WAS TURNING FURTHER R TO AVOID THE TFC. SOON AFTER, WE RECEIVED THE TA AND ALMOST IMMEDIATELY, RECEIVED THE RA. I CLBED PER THE RA INSTRUCTIONS AND TURNED AWAY FROM THE LOCATION OF THE TARGET. THE LAST TIME I LOOKED AT THE TCASII, HIS TARGET HAD MERGED WITH OUR AIRPLANE SYMBOL ON THE VSI, AND IT SHOWED 200 FT BELOW US. WE RPTED THE RA TO APCH AND THEN CONTACTED THEM UPON ARR. APCH SAID HE NEVER GOT WITHIN 400 FT, BUT I KNOW WHAT I SAW. WE NEVER VISUALLY ACQUIRED THE TARGET DUE TO HAZY -- SUNSET CONDITIONS.

Data retrieved from NASA's ASRS site as of July 2007 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.