ZID ARTCC radar controller descended an air carrier through an altitude occupied by a private jet.

Attributes
ACN	593727
Time
Date	200309
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : iiu.vortac
State Reference	KY
Altitude	msl single value : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Route In Use	arrival : on vectors
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zid.artcc
Operator	general aviation : corporate
Make Model Name	BAe 125 Series 800
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 20 controller time certified in position1 : 12
Person 2
Affiliation	government : faa
Function	controller : radar
Events
Anomaly	conflict : airborne critical non adherence : published procedure non adherence : required legal separation
Independent Detector	atc equipment : conflict alert other controllera other controllerb other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance other
Consequence	faa : investigated
Miss Distance	horizontal : 25200 vertical : 400
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Aircraft were northwest of iiu. Air carrier X issued a descent to FL310 to comply with internal LOA's. Traffic of aircraft Y overlooked. Turns and rates of dscnts did not ensure separation.

Original NASA ASRS Text

Title: ZID ARTCC RADAR CTLR DSNDED AN ACR THROUGH AN ALT OCCUPIED BY A PVT JET.

Narrative: ACFT WERE NW OF IIU. ACR X ISSUED A DSCNT TO FL310 TO COMPLY WITH INTERNAL LOA'S. TFC OF ACFT Y OVERLOOKED. TURNS AND RATES OF DSCNTS DID NOT ENSURE 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.