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

Attributes
ACN	185035
Time
Date	199107
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : anc
State Reference	AK
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : anc
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
ASRS Report	184035
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : developmental
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation non adherence : published procedure
Independent Detector	other other : unspecified atc
Resolutory Action	none taken : detected after the fact
Consequence	faa : investigated
Miss Distance	horizontal : 9000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was controller responsible for radar sector and monitoring developmental controller. I had my back turned momentarily to discuss some operational matters with the controller about to relieve us. I was not aware that a problem had occurred until after I was relieved. An adjacent controller reported the problem to facility management. A northbound IFR small aircraft Y passed close to a sbound air carrier X both at 3000 ft. Records showed the aircraft had passed with about 1 1/2 mi spacing. Due to a number of factors, I was not aware that small aircraft Y was entering my sector.

Original NASA ASRS Text

Title: ACR X HAD LTSS FROM SMA Y. SYS ERROR.

Narrative: I WAS CTLR RESPONSIBLE FOR RADAR SECTOR AND MONITORING DEVELOPMENTAL CTLR. I HAD MY BACK TURNED MOMENTARILY TO DISCUSS SOME OPERATIONAL MATTERS WITH THE CTLR ABOUT TO RELIEVE US. I WAS NOT AWARE THAT A PROBLEM HAD OCCURRED UNTIL AFTER I WAS RELIEVED. AN ADJACENT CTLR RPTED THE PROBLEM TO FACILITY MGMNT. A NBOUND IFR SMA Y PASSED CLOSE TO A SBOUND ACR X BOTH AT 3000 FT. RECORDS SHOWED THE ACFT HAD PASSED WITH ABOUT 1 1/2 MI SPACING. DUE TO A NUMBER OF FACTORS, I WAS NOT AWARE THAT SMA Y WAS ENTERING MY SECTOR.

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.