ZDC controller experienced operational error with 2 MD80's at 14000 ft.

Attributes
ACN	610488
Time
Date	200403
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	intersection : terri
State Reference	DE
Altitude	msl bound lower : 13000 msl bound upper : 14000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdc.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : holding descent : intermediate altitude
Route In Use	arrival : holding pattern
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zdc.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller time certified in position1 : 3.5
ASRS Report	610488
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	atc equipment : conflict alert other flight crewa
Resolutory Action	controller : issued new clearance flight crew : took evasive action
Consequence	faa : investigated
Miss Distance	horizontal : 22800 vertical : 500
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Holding at terri I descended aircraft X out of 14000 ft to 13000 ft in anticipation of an aircraft landing sbound descending to 14000 ft. Aircraft X did not descend as quickly as I anticipated. I issued a turn to aircraft Y but it was not enough.

Original NASA ASRS Text

Title: ZDC CTLR EXPERIENCED OPERROR WITH 2 MD80'S AT 14000 FT.

Narrative: HOLDING AT TERRI I DSNDED ACFT X OUT OF 14000 FT TO 13000 FT IN ANTICIPATION OF AN ACFT LNDG SBOUND DSNDING TO 14000 FT. ACFT X DID NOT DSND AS QUICKLY AS I ANTICIPATED. I ISSUED A TURN TO ACFT Y BUT IT WAS NOT ENOUGH.

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.