Aircraft X descent through occupied altitude had less than standard separation from aircraft Y. Syst...

Attributes
ACN	271264
Time
Date	199404
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : tol
State Reference	OH
Altitude	msl bound lower : 7000 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	tracon : tol tower : grb
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Route In Use	enroute : direct enroute airway : tol
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller military : 4 controller radar : 8
ASRS Report	271264
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	faa : investigated
Miss Distance	horizontal : 4800 vertical : 300
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Inter Facility Coordination Failure Operational Error

Narrative:

Aircraft X under control of en route center pointed out and approved to descend through tol airspace. Aircraft identify tag dropped somewhere in my airspace, which caused aircraft Y under my control to run closer than standard separation before primary target was eventually observed. I issued descent as my quickest, and in my judgement, best course of action to avoid conflict with aircraft X descending under center control. Performance of radar and computer was a factor in this incident.

Original NASA ASRS Text

Title: ACFT X DSCNT THROUGH OCCUPIED ALT HAD LTSS FROM ACFT Y. SYS ERROR.

Narrative: ACFT X UNDER CTL OF ENRTE CTR POINTED OUT AND APPROVED TO DSND THROUGH TOL AIRSPACE. ACFT IDENT TAG DROPPED SOMEWHERE IN MY AIRSPACE, WHICH CAUSED ACFT Y UNDER MY CTL TO RUN CLOSER THAN STANDARD SEPARATION BEFORE PRIMARY TARGET WAS EVENTUALLY OBSERVED. I ISSUED DSCNT AS MY QUICKEST, AND IN MY JUDGEMENT, BEST COURSE OF ACTION TO AVOID CONFLICT WITH ACFT X DSNDING UNDER CTR CTL. PERFORMANCE OF RADAR AND COMPUTER WAS A FACTOR IN THIS INCIDENT.

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.

Aircraft X descent through occupied altitude had less than standard separation from aircraft Y. System error.