ZDC controller experienced loss of separation with en route and descending aircraft at FL350.

Attributes
ACN	598658
Time
Date	200310
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zdc.artcc
State Reference	VA
Altitude	msl single value : 35000
Environment
Flight Conditions	VMC
Weather Elements	Turbulence
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc.artcc
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zdc.artcc
Operator	common carrier : air carrier
Make Model Name	A320
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 pilot : instrument
Experience	controller radar : 11 controller time certified in position1 : 5 flight time total : 2000
ASRS Report	598658
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 controllera
Resolutory Action	controller : issued new clearance flight crew : took evasive action
Consequence	faa : investigated
Miss Distance	horizontal : 8400 vertical : 1300
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Descended 1 aircraft from FL370 to FL330. Traffic was opposite direction at FL350. Corrected error by turning both aircraft.

Original NASA ASRS Text

Title: ZDC CTLR EXPERIENCED LOSS OF SEPARATION WITH ENRTE AND DSNDING ACFT AT FL350.

Narrative: DSNDED 1 ACFT FROM FL370 TO FL330. TFC WAS OPPOSITE DIRECTION AT FL350. CORRECTED ERROR BY TURNING BOTH ACFT.

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.