Controller lost legal separation between aircraft X and Y.

Attributes
ACN	427406
Time
Date	199902
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pit
State Reference	PA
Altitude	msl bound lower : 12000 msl bound upper : 12000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Flight Phase	descent other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Experience	controller radar : 17 flight time total : 220
ASRS Report	427406
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	none taken : unable
Consequence	faa : investigated
Miss Distance	horizontal : 20000 vertical : 0
Supplementary
Air Traffic Incident	Operational Error

Narrative:

Turned aircraft #2 (aircraft Y) behind aircraft #1 (aircraft X) with tailwind. Aircraft #2 (aircraft Y) caught back side of aircraft #1 (aircraft X).

Original NASA ASRS Text

Title: CTLR LOST LEGAL SEPARATION BTWN ACFT X AND Y.

Narrative: TURNED ACFT #2 (ACFT Y) BEHIND ACFT #1 (ACFT X) WITH TAILWIND. ACFT #2 (ACFT Y) CAUGHT BACK SIDE OF ACFT #1 (ACFT X).

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.