ZTL controller experienced operational error during heavy traffic period at FL310.

Attributes
ACN	608220
Time
Date	200402
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : dbn.vortac
State Reference	GA
Altitude	msl single value : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	B767-300 and 300 ER
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : ztl.artcc
Make Model Name	DC-9 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 40.5 controller time certified in position1 : 36
ASRS Report	608220
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	conflict : airborne critical non adherence : required legal separation
Independent Detector	atc equipment : conflict alert aircraft equipment : tcas
Resolutory Action	controller : issued new clearance flight crew : took evasive action
Consequence	faa : investigated
Miss Distance	horizontal : 750 vertical : 100
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Was working dublin high altitude sector that had heavy en route traffic, and heavy en route traffic with aircraft climbing and descending through sector. Aircraft X was transitioning from FL370 to FL330. When he checked on frequency, I assigned him FL310 on an assigned heading to parallel a northbound FL330 that was climbing to FL350. Aircraft Y was sbound at FL310 (wrong altitude for direction of flight which is required by ZJX). I descended aircraft X to FL310 to get under northbound traffic that was climbing to FL350. It was my intention to drop aircraft to FL290 after he cleared another sbound aircraft. I was distred due to high volume of traffic and failed to notice sbound aircraft Y. I attempted to turn aircraft X to a 270 degree heading and then aircraft Y to a 090 degree heading. Conflict alert activated on both aircraft. TCASII activated.

Original NASA ASRS Text

Title: ZTL CTLR EXPERIENCED OPERROR DURING HVY TFC PERIOD AT FL310.

Narrative: WAS WORKING DUBLIN HIGH ALT SECTOR THAT HAD HVY ENRTE TFC, AND HVY ENRTE TFC WITH ACFT CLBING AND DSNDING THROUGH SECTOR. ACFT X WAS TRANSITIONING FROM FL370 TO FL330. WHEN HE CHKED ON FREQ, I ASSIGNED HIM FL310 ON AN ASSIGNED HDG TO PARALLEL A NBOUND FL330 THAT WAS CLBING TO FL350. ACFT Y WAS SBOUND AT FL310 (WRONG ALT FOR DIRECTION OF FLT WHICH IS REQUIRED BY ZJX). I DSNDED ACFT X TO FL310 TO GET UNDER NBOUND TFC THAT WAS CLBING TO FL350. IT WAS MY INTENTION TO DROP ACFT TO FL290 AFTER HE CLRED ANOTHER SBOUND ACFT. I WAS DISTRED DUE TO HIGH VOLUME OF TFC AND FAILED TO NOTICE SBOUND ACFT Y. I ATTEMPTED TO TURN ACFT X TO A 270 DEG HDG AND THEN ACFT Y TO A 090 DEG HDG. CONFLICT ALERT ACTIVATED ON BOTH ACFT. TCASII ACTIVATED.

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.