ZOB controller lost separation with climbing DC9 and en route C441.

Attributes
ACN	578077
Time
Date	200301
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dtw.airport
State Reference	MI
Altitude	msl bound lower : 15000 msl bound upper : 16000
Environment
Flight Conditions	IMC
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : zob.artcc
Operator	common carrier : air carrier
Make Model Name	DC-9 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zob.artcc
Operator	general aviation : personal
Make Model Name	Conquest I/Conquest II
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : non radar
Qualification	controller : radar
Experience	controller limited radar : 1 controller military : 4 controller radar : 1
ASRS Report	578077
Person 2
Affiliation	government : faa
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	atc equipment : conflict alert other controllera
Resolutory Action	controller : issued new clearance
Consequence	faa : investigated
Miss Distance	horizontal : 18000 vertical : 600
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was working the radar associate position. It was a fairly busy time. The radar controller climbed aircraft X to 16000 ft with 15000 ft in the data block. Aircraft Y was direct mbs at 16000 ft. I did not hear the radar controller climb aircraft X to 16000 ft, because I was off line doing something else. The data blocks showed the 2 planes to be separated. When the conflict alert started, the radar controller immediately took action and descended aircraft X back to 15000 ft. It was not in time and separation was lost. What caused the problem? It was a busy period and the controller was starting to fall behind. I'm not really sure what you can do to prevent it. It was a mistake. Just have a little more awareness.

Original NASA ASRS Text

Title: ZOB CTLR LOST SEPARATION WITH CLBING DC9 AND ENRTE C441.

Narrative: I WAS WORKING THE RADAR ASSOCIATE POS. IT WAS A FAIRLY BUSY TIME. THE RADAR CTLR CLBED ACFT X TO 16000 FT WITH 15000 FT IN THE DATA BLOCK. ACFT Y WAS DIRECT MBS AT 16000 FT. I DID NOT HEAR THE RADAR CTLR CLB ACFT X TO 16000 FT, BECAUSE I WAS OFF LINE DOING SOMETHING ELSE. THE DATA BLOCKS SHOWED THE 2 PLANES TO BE SEPARATED. WHEN THE CONFLICT ALERT STARTED, THE RADAR CTLR IMMEDIATELY TOOK ACTION AND DSNDED ACFT X BACK TO 15000 FT. IT WAS NOT IN TIME AND SEPARATION WAS LOST. WHAT CAUSED THE PROB? IT WAS A BUSY PERIOD AND THE CTLR WAS STARTING TO FALL BEHIND. I'M NOT REALLY SURE WHAT YOU CAN DO TO PREVENT IT. IT WAS A MISTAKE. JUST HAVE A LITTLE MORE AWARENESS.

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.