Cpr crew experienced TCAS RA while descending.

Attributes
ACN	687708
Time
Date	200602
Place
Locale Reference	navaid : atl.vortac
State Reference	GA
Altitude	msl single value : 6500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : a80.tracon
Operator	general aviation : corporate
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : a80.tracon
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	climbout : initial
Flight Plan	VFR
Person 1
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : atp
Experience	flight time last 90 days : 30 flight time total : 10000 flight time type : 300
ASRS Report	687708
Person 2
Affiliation	company : corporate
Function	flight crew : first officer
Events
Anomaly	conflict : nmac
Independent Detector	aircraft equipment : tcas other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance controller : issued advisory controller : separated traffic flight crew : took evasive action
Miss Distance	vertical : 100
Supplementary
Problem Areas	Navigational Facility ATC Human Performance
Primary Problem	ATC Human Performance

Narrative:

I was cruising at FL280 when ZTL issued a descent clearance to cross dehan at 8000 ft on the awson arrival. During the descent we were handed off to atl approach and given further clearance to continue descent to 4000 ft. At approximately 9000 ft; atl informed us of unidented VFR traffic and gave us a heading change to avoid it during the descent. As we passed 6500 ft on the way to 4000 ft; atl informed us to climb to 7000 ft. At this point we received a TCAS RA to climb. I initiated an immediate climb; however; atl still wanted us at 7000 ft. As I was climbing; my first officer and I spotted additional traffic at the 10 O'clock high position which prevented me from climbing much above 7500 ft. In the meantime; the RA was closing on us from below and came within 100 ft of my aircraft as I was passing through 7200 ft. The odd thing is that the RA disappeared at this point never to be seen again. Atl did not see the RA 'target;' nor did they know about the aircraft at the 10 O'clock position. In addition; the 10 O'clock position aircraft was not on our TCAS. We were fortunate to have visually spotted this aircraft in time so we didn't create a collision hazard during the climb escape maneuver.

Original NASA ASRS Text

Title: CPR CREW EXPERIENCED TCAS RA WHILE DSNDING.

Narrative: I WAS CRUISING AT FL280 WHEN ZTL ISSUED A DSCNT CLRNC TO CROSS DEHAN AT 8000 FT ON THE AWSON ARR. DURING THE DSCNT WE WERE HANDED OFF TO ATL APCH AND GIVEN FURTHER CLRNC TO CONTINUE DSCNT TO 4000 FT. AT APPROX 9000 FT; ATL INFORMED US OF UNIDENTED VFR TFC AND GAVE US A HDG CHANGE TO AVOID IT DURING THE DSCNT. AS WE PASSED 6500 FT ON THE WAY TO 4000 FT; ATL INFORMED US TO CLB TO 7000 FT. AT THIS POINT WE RECEIVED A TCAS RA TO CLB. I INITIATED AN IMMEDIATE CLB; HOWEVER; ATL STILL WANTED US AT 7000 FT. AS I WAS CLBING; MY FO AND I SPOTTED ADDITIONAL TFC AT THE 10 O'CLOCK HIGH POS WHICH PREVENTED ME FROM CLBING MUCH ABOVE 7500 FT. IN THE MEANTIME; THE RA WAS CLOSING ON US FROM BELOW AND CAME WITHIN 100 FT OF MY ACFT AS I WAS PASSING THROUGH 7200 FT. THE ODD THING IS THAT THE RA DISAPPEARED AT THIS POINT NEVER TO BE SEEN AGAIN. ATL DID NOT SEE THE RA 'TARGET;' NOR DID THEY KNOW ABOUT THE ACFT AT THE 10 O'CLOCK POS. IN ADDITION; THE 10 O'CLOCK POS ACFT WAS NOT ON OUR TCAS. WE WERE FORTUNATE TO HAVE VISUALLY SPOTTED THIS ACFT IN TIME SO WE DIDN'T CREATE A COLLISION HAZARD DURING THE CLB ESCAPE MANEUVER.

Data retrieved from NASA's ASRS site as of January 2009 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.