ZSE controller experienced operational error at FL364 after releasing control to ZOA controller.

Attributes
ACN	613767
Time
Date	200403
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zse.artcc
State Reference	WA
Altitude	msl single value : 36400
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zse.artcc artcc : zoa.artcc artcc : zhu.artcc
Operator	common carrier : air carrier
Make Model Name	B777 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zse.artcc
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 17
ASRS Report	613767
Person 2
Affiliation	government : faa
Function	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	atc equipment : conflict alert other controllera
Resolutory Action	none taken : insufficient time
Consequence	faa : investigated
Miss Distance	horizontal : 23400 vertical : 1400
Supplementary
Problem Areas	ATC Human Performance Airspace Structure
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was the radar controller at ZSE, sector 14, a high altitude sector surrounding klamath falls, or. I had accepted a pointout on air carrier X as it transited a corner of my airspace. ZOA requested to know who was working the air carrier X. I told them that seattle sector 13 was working air carrier X, but that oakland could have control of the aircraft in my sector. I failed to notice that air carrier Y was about to enter my airspace from sector 13 and would pass the air carrier X with less than 5 mi lateral separation. The 2 aircraft were vertically separated until I released control of the air carrier X to ZOA who then descended him into air carrier Y's altitude. I became aware of error when immediate alert went off. This error occurred in an area where 3 sectors come together and crossing traffic is common. It is sometimes difficult keeping track of which sector is actually working each aircraft.

Original NASA ASRS Text

Title: ZSE CTLR EXPERIENCED OPERROR AT FL364 AFTER RELEASING CTL TO ZOA CTLR.

Narrative: I WAS THE RADAR CTLR AT ZSE, SECTOR 14, A HIGH ALT SECTOR SURROUNDING KLAMATH FALLS, OR. I HAD ACCEPTED A POINTOUT ON ACR X AS IT TRANSITED A CORNER OF MY AIRSPACE. ZOA REQUESTED TO KNOW WHO WAS WORKING THE ACR X. I TOLD THEM THAT SEATTLE SECTOR 13 WAS WORKING ACR X, BUT THAT OAKLAND COULD HAVE CTL OF THE ACFT IN MY SECTOR. I FAILED TO NOTICE THAT ACR Y WAS ABOUT TO ENTER MY AIRSPACE FROM SECTOR 13 AND WOULD PASS THE ACR X WITH LESS THAN 5 MI LATERAL SEPARATION. THE 2 ACFT WERE VERTLY SEPARATED UNTIL I RELEASED CTL OF THE ACR X TO ZOA WHO THEN DSNDED HIM INTO ACR Y'S ALT. I BECAME AWARE OF ERROR WHEN IMMEDIATE ALERT WENT OFF. THIS ERROR OCCURRED IN AN AREA WHERE 3 SECTORS COME TOGETHER AND XING TFC IS COMMON. IT IS SOMETIMES DIFFICULT KEEPING TRACK OF WHICH SECTOR IS ACTUALLY WORKING EACH ACFT.

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.