ZID associate controller observed operational error at FL210 involving B737 and carj aircraft.

Attributes
ACN	650683
Time
Date	200502
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : tvt.vor
State Reference	OH
Altitude	msl bound lower : 21000 msl bound upper : 22000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Aircraft 2
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	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 17 controller time certified in position1 : 17
ASRS Report	650683
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 : anomaly accepted
Consequence	faa : investigated
Miss Distance	horizontal : 24000 vertical : 400
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Air carrier X inbound to cle at FL240 was issued descent to FL210. Air carrier Y at FL220 over tvt was traffic. Trainee did not recognize air carrier X as traffic. Conflict alert activated; turns issued separation was lost.

Original NASA ASRS Text

Title: ZID ASSOCIATE CTLR OBSERVED OPERROR AT FL210 INVOLVING B737 AND CARJ ACFT.

Narrative: ACR X INBOUND TO CLE AT FL240 WAS ISSUED DSCNT TO FL210. ACR Y AT FL220 OVER TVT WAS TFC. TRAINEE DID NOT RECOGNIZE ACR X AS TFC. CONFLICT ALERT ACTIVATED; TURNS ISSUED SEPARATION WAS LOST.

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.