While in terminal airspace two air carrier aircraft sequentially followed TCAS resolution advisories...

Narrative:

While we were level at 5;000 MSL in cavu conditions; an air carrier flight in front of us was given traffic; a cirrus; VFR 4;500 MSL 12 o'clock. The air carrier reported traffic alerts and claims cirrus is not at 4;500 MSL...much closer. Approach gave us the same traffic; 12 o'clock; 4;500 MSL and VFR. We did not have visual contact; but the cirrus reported us in sight (said he had our lights). As we closed; we got simultaneous 'traffic' and 'climb; climb' RA alerts. Cirrus showed 400 below moving to 300 below. The first officer who was pilot flying began a climb away from traffic in response to the RA. I advised approach who replied that the cirrus 'said he was at 4;500 ft and radar confirms'. We climbed to approximately 5;400 ft and the RA ended as traffic passed below us and slightly right of the nose. I caught a glimpse of the cirrus passing to the right and he indeed did not look to be anywhere near 500 ft below us (or in this case it should have been 900 ft with our climb). I could see the occupants clearly. I advised approach we were returning to our assigned altitude and in response got a frequency change and 'that was that'.

Original NASA ASRS Text

Title: While in terminal airspace two air carrier aircraft sequentially followed TCAS Resolution Advisories with respect to a Cirrus aircraft apparently well above his assigned altitude and conflicting with that of the air carriers.

Narrative: While we were level at 5;000 MSL in CAVU conditions; an air carrier flight in front of us was given traffic; a Cirrus; VFR 4;500 MSL 12 o'clock. The air carrier reported traffic alerts and claims Cirrus is not at 4;500 MSL...much closer. Approach gave us the same traffic; 12 o'clock; 4;500 MSL and VFR. We did not have visual contact; but the Cirrus reported us in sight (said he had our lights). As we closed; we got simultaneous 'Traffic' and 'Climb; Climb' RA alerts. Cirrus showed 400 below moving to 300 below. The First Officer who was pilot flying began a climb away from traffic in response to the RA. I advised Approach who replied that the Cirrus 'said he was at 4;500 FT and radar confirms'. We climbed to approximately 5;400 FT and the RA ended as traffic passed below us and slightly right of the nose. I caught a glimpse of the Cirrus passing to the right and he indeed did not look to be anywhere near 500 FT below us (or in this case it should have been 900 FT with our climb). I could see the occupants clearly. I advised Approach we were returning to our assigned altitude and in response got a frequency change and 'that was that'.

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.

Attributes
ACN	966520
Time
Date	201108
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Cirrus Aircraft Undifferentiated
Flight Plan	VFR
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Conflict NMAC
Miss Distance	Horizontal 0 Vertical 350

While in terminal airspace two air carrier aircraft sequentially followed TCAS resolution advisories with respect to a cirrus aircraft apparently well above his assigned altitude and conflicting with that of the air carriers.