ZOB controller experienced loss of separation at FL310 during descent.

Attributes
ACN	600114
Time
Date	200311
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : fnt.airport
State Reference	MI
Altitude	msl single value : 31000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob.artcc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zob.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	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 2
ASRS Report	600114
Person 2
Affiliation	government : faa
Function	controller : handoff position
Events
Anomaly	conflict : airborne less severe non adherence : published procedure 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 : 25200 vertical : 1200
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was working the beginning of the ord push. WX was a factor due to turbulence at various altitude and locations. When air carrier X asked for a descent, I overlooked air carrier Y and issued the clearance. At that point, my attention was drawn to the east side of my sector because of an intruder code en route to my airspace. It turned out to be air carrier Z, who was on a bad code. I was talking to the d-side to find out who the intruder code was. He got on the manual coordination line with yyz to find out. I also picked up a manual coordination line to take a radar handoff from yyz. The d-side released the line and pointed out the aircraft were in conflict and that startled me. They appeared to be past each other, so I took no action. After being relieved by the d-side, who was starting a relief briefing prior to this to a d-side only controller, I checked with the supervisor to see if the odep was activated. She said no and I thought that they must have been clear.

Original NASA ASRS Text

Title: ZOB CTLR EXPERIENCED LOSS OF SEPARATION AT FL310 DURING DSCNT.

Narrative: I WAS WORKING THE BEGINNING OF THE ORD PUSH. WX WAS A FACTOR DUE TO TURB AT VARIOUS ALT AND LOCATIONS. WHEN ACR X ASKED FOR A DSCNT, I OVERLOOKED ACR Y AND ISSUED THE CLRNC. AT THAT POINT, MY ATTN WAS DRAWN TO THE E SIDE OF MY SECTOR BECAUSE OF AN INTRUDER CODE ENRTE TO MY AIRSPACE. IT TURNED OUT TO BE ACR Z, WHO WAS ON A BAD CODE. I WAS TALKING TO THE D-SIDE TO FIND OUT WHO THE INTRUDER CODE WAS. HE GOT ON THE MANUAL COORD LINE WITH YYZ TO FIND OUT. I ALSO PICKED UP A MANUAL COORD LINE TO TAKE A RADAR HDOF FROM YYZ. THE D-SIDE RELEASED THE LINE AND POINTED OUT THE ACFT WERE IN CONFLICT AND THAT STARTLED ME. THEY APPEARED TO BE PAST EACH OTHER, SO I TOOK NO ACTION. AFTER BEING RELIEVED BY THE D-SIDE, WHO WAS STARTING A RELIEF BRIEFING PRIOR TO THIS TO A D-SIDE ONLY CTLR, I CHKED WITH THE SUPVR TO SEE IF THE ODEP WAS ACTIVATED. SHE SAID NO AND I THOUGHT THAT THEY MUST HAVE BEEN CLR.

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.