Visual separation used by ARTCC controller in positive control area.

Attributes
ACN	129235
Time
Date	198911
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : wrl
State Reference	WY
Altitude	msl bound lower : 20000 msl bound upper : 20000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zlc tower : lga
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent other
Flight Plan	IFR
Aircraft 2
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
Experience	controller radar : 4
ASRS Report	129235
Person 2
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument
Events
Anomaly	non adherence : required legal separation non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Miss Distance	horizontal : 12000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

2 aircraft landing wrl. WX VFR. Second aircraft got first aircraft in sight (in positive control area). I cleared the second aircraft to follow the first on a visibility approach. Aircraft went down to 2 mi longitudinally at FL200'. I feel foolish. I forgot there is no VFR sep (or visibility sep) in positive control area! I won't do that again!

Original NASA ASRS Text

Title: VISUAL SEPARATION USED BY ARTCC CTLR IN PCA.

Narrative: 2 ACFT LNDG WRL. WX VFR. SECOND ACFT GOT FIRST ACFT IN SIGHT (IN PCA). I CLRED THE SECOND ACFT TO FOLLOW THE FIRST ON A VIS APCH. ACFT WENT DOWN TO 2 MI LONGITUDINALLY AT FL200'. I FEEL FOOLISH. I FORGOT THERE IS NO VFR SEP (OR VIS SEP) IN PCA! I WON'T DO THAT AGAIN!

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.