ZDC controller issued incorrect altitude, resulting in operational error.

Attributes
ACN	599519
Time
Date	200311
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : hgr.airport
State Reference	MD
Altitude	agl single value : 4000
Environment
Flight Conditions	Marginal
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : zdc.artcc
Operator	general aviation : personal
Make Model Name	Baron 55/Cochise
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zdc.artcc
Operator	general aviation : personal
Make Model Name	Cessna 150
Operating Under FAR Part	Part 91
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 13 controller time certified in position1 : 12
ASRS Report	599519
Person 2
Affiliation	other
Function	flight crew : single pilot
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	atc equipment : conflict alert other controllera
Resolutory Action	none taken : detected after the fact
Consequence	faa : investigated
Miss Distance	horizontal : 18000 vertical : 600
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Aircraft was being vectored for approach to hgr at 4000 ft. Aircraft #2 was also going to hgr and was issued 4000 ft, but I thought I issued 5000 ft.

Original NASA ASRS Text

Title: ZDC CTLR ISSUED INCORRECT ALT, RESULTING IN OPERROR.

Narrative: ACFT WAS BEING VECTORED FOR APCH TO HGR AT 4000 FT. ACFT #2 WAS ALSO GOING TO HGR AND WAS ISSUED 4000 FT, BUT I THOUGHT I ISSUED 5000 FT.

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.