MD88 and a TCASII equipped aircraft had less than legal separation in ZME class a.

Attributes
ACN	541831
Time
Date	200203
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : pxv.vortac
State Reference	IN
Altitude	msl bound lower : 36000 msl bound upper : 31000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme.artcc
Operator	common carrier : air carrier
Make Model Name	MD-88
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	descent : intermediate altitude
Route In Use	arrival star : mosey.mosey5
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zme.artcc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
ASRS Report	541831
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	conflict : airborne critical non adherence : published procedure non adherence : far other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : took evasive action none taken : detected after the fact other
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Ambiguous

Narrative:

I was the PF en route to cvg. ATC vectored us north direct pxv to approach cvg from southwest along the mosey 5 arrival. Shortly after the clearance direct pxv, approximately 55 NM south heading 360 degrees, there was a TCASII traffic alert. This was followed shortly after by an RA, 'descend, descend.' I immediately began a descent and began a slow roll and turn away from the conflict. I flew the airplane to 30600 ft while the first officer made a call to ATC. The other aircraft took evasive action as well per direction from his TCASII. 'Clear of conflict' was called out by the TCASII. We climbed back up to FL310 in accordance with ATC direction and proceeded to cvg. The rest of the flight was uneventful.

Original NASA ASRS Text

Title: MD88 AND A TCASII EQUIPPED ACFT HAD LESS THAN LEGAL SEPARATION IN ZME CLASS A.

Narrative: I WAS THE PF ENRTE TO CVG. ATC VECTORED US N DIRECT PXV TO APCH CVG FROM SW ALONG THE MOSEY 5 ARR. SHORTLY AFTER THE CLRNC DIRECT PXV, APPROX 55 NM S HEADING 360 DEGS, THERE WAS A TCASII TFC ALERT. THIS WAS FOLLOWED SHORTLY AFTER BY AN RA, 'DSND, DSND.' I IMMEDIATELY BEGAN A DSCNT AND BEGAN A SLOW ROLL AND TURN AWAY FROM THE CONFLICT. I FLEW THE AIRPLANE TO 30600 FT WHILE THE FO MADE A CALL TO ATC. THE OTHER ACFT TOOK EVASIVE ACTION AS WELL PER DIRECTION FROM HIS TCASII. 'CLR OF CONFLICT' WAS CALLED OUT BY THE TCASII. WE CLBED BACK UP TO FL310 IN ACCORDANCE WITH ATC DIRECTION AND PROCEEDED TO CVG. THE REST OF THE FLT WAS UNEVENTFUL.

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.