Air carrier X had less than standard separation from air carrier Y. System error.

Attributes
ACN	129430
Time
Date	198911
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : spa
State Reference	SC
Altitude	msl bound lower : 29400 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
ASRS Report	129430
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	atc equipment other atc equipment : unspecified
Resolutory Action	none taken : anomaly accepted
Consequence	faa : investigated
Miss Distance	horizontal : 0 vertical : 1600
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I had just opened sector 34 GA high. Air carrier X checked on at FL290. I climbed air carrier X to FL310. Air carrier Y was right over air carrier X at FL310 heading southwest, opp direction to air carrier Y. I did not see air carrier Y. C/a activated when air carrier X passed through FL294. In that the aircraft had passed each other, no action for further sep was taken. I don't have any explanation as to why I didn't see the conflict. I knew air carrier Y was there, but failed to recognize the aircraft as traffic for air carrier X. The following is the traffic situation as I recall it. The sector had been open for less than 3 mins. I had approximately 8 aircraft in the sector.

Original NASA ASRS Text

Title: ACR X HAD LESS THAN STANDARD SEPARATION FROM ACR Y. SYSTEM ERROR.

Narrative: I HAD JUST OPENED SECTOR 34 GA HIGH. ACR X CHKED ON AT FL290. I CLBED ACR X TO FL310. ACR Y WAS RIGHT OVER ACR X AT FL310 HDG SW, OPP DIRECTION TO ACR Y. I DID NOT SEE ACR Y. C/A ACTIVATED WHEN ACR X PASSED THROUGH FL294. IN THAT THE ACFT HAD PASSED EACH OTHER, NO ACTION FOR FURTHER SEP WAS TAKEN. I DON'T HAVE ANY EXPLANATION AS TO WHY I DIDN'T SEE THE CONFLICT. I KNEW ACR Y WAS THERE, BUT FAILED TO RECOGNIZE THE ACFT AS TFC FOR ACR X. THE FOLLOWING IS THE TFC SITUATION AS I RECALL IT. THE SECTOR HAD BEEN OPEN FOR LESS THAN 3 MINS. I HAD APPROX 8 ACFT IN THE SECTOR.

Data retrieved from NASA's ASRS site as of August 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.