ZID controller experienced operational error at FL230 with climbing and descending aircraft.

Attributes
ACN	645186
Time
Date	200501
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : hyk.vortac
State Reference	KY
Altitude	msl single value : 23000
Aircraft 1
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	Regional Jet 200 ER&LR
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zid.artcc
Operator	general aviation : personal
Make Model Name	Learjet 45
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller military : 4 controller radar : 17 controller time certified in position1 : 5
ASRS Report	645186
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
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
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Aircraft Y was cleared to climb and maintain FL230. I thought I stopped him at FL200. Air carrier X was cleared to descend to FL210. Adep and conflict alert went off at the same time too late to resolve the conflict.

Original NASA ASRS Text

Title: ZID CTLR EXPERIENCED OPERROR AT FL230 WITH CLBING AND DSNDING ACFT.

Narrative: ACFT Y WAS CLRED TO CLB AND MAINTAIN FL230. I THOUGHT I STOPPED HIM AT FL200. ACR X WAS CLRED TO DSND TO FL210. ADEP AND CONFLICT ALERT WENT OFF AT THE SAME TIME TOO LATE TO RESOLVE THE CONFLICT.

Data retrieved from NASA's ASRS site as of January 2009 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.