ZAU radar controller unable to maintain separation between 2 aircraft because of sector saturation.

Attributes
ACN	544729
Time
Date	200204
Day	Wed
Local Time Of Day	1801 To 2400
Place
State Reference	LA
Altitude	msl single value : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhu.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zhu.artcc
Operator	common carrier : air carrier
Make Model Name	Regional Jet 200 ER&LR
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 non radar : 2 controller radar : 10 controller time certified in position1 : 10
ASRS Report	544729
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation non adherence : published procedure other anomaly other
Independent Detector	atc equipment : conflict alert atc equipment other atc equipment : radar other controllera other flight crewa other flight crewb
Miss Distance	horizontal : 24000 vertical : 1400
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

18 aircraft on frequency. I was asked to provide in trail to dfw airport. I issued vectors to 4 aircraft including the 2 aircraft involved. Because of the many other aircraft in the area, I had to move 2 other aircraft in the area to avoid conflictions with the aircraft on vectors. During my scan of the radar I noticed the 2 aircraft in confliction, but was only able to use altitude separation initially due to other traffic above and below the aircraft involved. I initiated vectors to both aircraft and as soon as possible I issued a descent to aircraft X, MD80, and a climb to aircraft Y, CRJ2, I was unable to maintain separation.

Original NASA ASRS Text

Title: ZAU RADAR CTLR UNABLE TO MAINTAIN SEPARATION BTWN 2 ACFT BECAUSE OF SECTOR SATURATION.

Narrative: 18 ACFT ON FREQ. I WAS ASKED TO PROVIDE IN TRAIL TO DFW ARPT. I ISSUED VECTORS TO 4 ACFT INCLUDING THE 2 ACFT INVOLVED. BECAUSE OF THE MANY OTHER ACFT IN THE AREA, I HAD TO MOVE 2 OTHER ACFT IN THE AREA TO AVOID CONFLICTIONS WITH THE ACFT ON VECTORS. DURING MY SCAN OF THE RADAR I NOTICED THE 2 ACFT IN CONFLICTION, BUT WAS ONLY ABLE TO USE ALT SEPARATION INITIALLY DUE TO OTHER TFC ABOVE AND BELOW THE ACFT INVOLVED. I INITIATED VECTORS TO BOTH ACFT AND AS SOON AS POSSIBLE I ISSUED A DSCNT TO ACFT X, MD80, AND A CLB TO ACFT Y, CRJ2, I WAS UNABLE TO MAINTAIN SEPARATION.

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.