B737 and an MD88 had less than legal separation in ZTL class a airspace.

Attributes
ACN	521345
Time
Date	200108
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : atl.airport
State Reference	GA
Altitude	msl single value : 29000
Environment
Flight Conditions	IMC
Weather Elements	Thunderstorm
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	cruise : level ground : preflight
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	MD-88
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 220 flight time total : 15000 flight time type : 12000
ASRS Report	521345
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	conflict : airborne critical inflight encounter : weather inflight encounter other non adherence : published procedure non adherence : far non adherence : required legal separation other anomaly other
Independent Detector	aircraft equipment : tcas other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : took evasive action none taken : detected after the fact other
Miss Distance	horizontal : 24000
Supplementary
Problem Areas	ATC Human Performance Weather
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Deviating for thunderstorm avoidance, ATC gave us clearance to deviate. We turned. I advised ATC we were turning towards vxv. Apparently, as we turned, an air carrier Y flight appeared at our altitude. ATC told us to climb to FL310. We complied. TCASII did give a TA then an RA. Supplemental information from acn 521372: approximately XA40, received TA, immediately followed by RA. Disengaged autoplt and initiated a climb. During the climb, queried ATC about other aircraft on 2 different frequencys. Climbed approximately 600 ft above assigned altitude. Once clear, descended back to FL290.

Original NASA ASRS Text

Title: B737 AND AN MD88 HAD LESS THAN LEGAL SEPARATION IN ZTL CLASS A AIRSPACE.

Narrative: DEVIATING FOR TSTM AVOIDANCE, ATC GAVE US CLRNC TO DEVIATE. WE TURNED. I ADVISED ATC WE WERE TURNING TOWARDS VXV. APPARENTLY, AS WE TURNED, AN ACR Y FLT APPEARED AT OUR ALT. ATC TOLD US TO CLB TO FL310. WE COMPLIED. TCASII DID GIVE A TA THEN AN RA. SUPPLEMENTAL INFO FROM ACN 521372: APPROX XA40, RECEIVED TA, IMMEDIATELY FOLLOWED BY RA. DISENGAGED AUTOPLT AND INITIATED A CLB. DURING THE CLB, QUERIED ATC ABOUT OTHER ACFT ON 2 DIFFERENT FREQS. CLBED APPROX 600 FT ABOVE ASSIGNED ALT. ONCE CLR, DSNDED BACK TO FL290.

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.