Air carrier X had less than standard separation from atx Y. System error.

Attributes
ACN	122011
Time
Date	198909
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : djb
State Reference	OH
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : day
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	other
Route In Use	enroute airway : zob
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air taxi
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
ASRS Report	122011
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	atc equipment other atc equipment : unspecified
Resolutory Action	none taken : detected after the fact
Consequence	faa : investigated
Miss Distance	horizontal : 23400 vertical : 600
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

We were holding at tripe intersection. The data block dropped off air carrier X, which was in the hold at 8000'. About 10 mins later, an atx Y was in descent to 7000'. The 2 aircraft came within 600' and 3.9 mi. The traffic load was heavy and I didn't catch air carrier Y in the hold at tripe intersection. Controller error.

Original NASA ASRS Text

Title: ACR X HAD LESS THAN STANDARD SEPARATION FROM ATX Y. SYSTEM ERROR.

Narrative: WE WERE HOLDING AT TRIPE INTXN. THE DATA BLOCK DROPPED OFF ACR X, WHICH WAS IN THE HOLD AT 8000'. ABOUT 10 MINS LATER, AN ATX Y WAS IN DSCNT TO 7000'. THE 2 ACFT CAME WITHIN 600' AND 3.9 MI. THE TFC LOAD WAS HEAVY AND I DIDN'T CATCH ACR Y IN THE HOLD AT TRIPE INTXN. CTLR ERROR.

Data retrieved from NASA's ASRS site as of August 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.