ZID supervisor observed operational error at FL300.

Attributes
ACN	610656
Time
Date	200403
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : hvq.vor
State Reference	WV
Altitude	msl bound lower : 30000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid.artcc
Operator	general aviation : personal
Make Model Name	Citation III, VI, VII
Operating Under FAR Part	Part 91
Flight Phase	descent : intermediate altitude descent : vacating altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	Regional Jet CL65, Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : supervisor
Qualification	controller : radar
Experience	controller radar : 32 controller time certified in position1 : 30
ASRS Report	610656
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	controller : issued new clearance
Consequence	faa : investigated
Miss Distance	horizontal : 9000 vertical : 1000
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Controller accepted handoff on aircraft X, inbound to cmn who was head-on with air carrier Y. Aircraft X called on, at FL310, and controller overlooked air carrier Y and descended aircraft X into acby. Controller tried to rescind clearance to aircraft X, but aircraft had already left FL310. Human error.

Original NASA ASRS Text

Title: ZID SUPVR OBSERVED OPERROR AT FL300.

Narrative: CTLR ACCEPTED HDOF ON ACFT X, INBOUND TO CMN WHO WAS HEAD-ON WITH ACR Y. ACFT X CALLED ON, AT FL310, AND CTLR OVERLOOKED ACR Y AND DSNDED ACFT X INTO ACBY. CTLR TRIED TO RESCIND CLRNC TO ACFT X, BUT ACFT HAD ALREADY LEFT FL310. HUMAN ERROR.

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.