ARTCC radar controller at ZNY descended a B727 to an altitude occupied by another B727.

Attributes
ACN	491680
Time
Date	200011
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : cvg.vortac
State Reference	KY
Altitude	msl single value : 13500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	PA-60 600 Aerostar
Operating Under FAR Part	Part 91
Navigation In Use	other other vortac
Flight Phase	cruise : level
Route In Use	enroute : direct
Flight Plan	None
Aircraft 2
Controlling Facilities	artcc : zny.artcc
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar pilot : private
Experience	controller military : 2 controller radar : 15 controller time certified in position1 : 15 flight time total : 110
ASRS Report	762
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : vor and gps other flight crewa
Resolutory Action	flight crew : became reoriented
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Air carrier X was northbound landing syr. Air carrier Y was swbound going toward ewc. I was working sector 34 and had control from sector 75 to descend air carrier X reference Z traffic -- 1 at FL290 and the air carrier Y at FL310. I was descending air carrier X from FL330 to FL310 using limited data only on the other aircraft and forgot the air carrier Y. The air carrier Y was out of my airspace however, I dropped the data and never pulled it back up. I also thought the air carrier Y was heading toward psb. Mostly because a large majority of traffic going to that sector goes toward psb. I believe even though I knew the air carrier Y was there that if I pulled up data block again even though he was out of my airspace, I would have been more hesitant to descend air carrier X jet.

Original NASA ASRS Text

Title: ARTCC RADAR CTLR AT ZNY DSNDED A B727 TO AN ALT OCCUPIED BY ANOTHER B727.

Narrative: ACR X WAS NBOUND LNDG SYR. ACR Y WAS SWBOUND GOING TOWARD EWC. I WAS WORKING SECTOR 34 AND HAD CTL FROM SECTOR 75 TO DSND ACR X REF Z TFC -- 1 AT FL290 AND THE ACR Y AT FL310. I WAS DSNDING ACR X FROM FL330 TO FL310 USING LIMITED DATA ONLY ON THE OTHER ACFT AND FORGOT THE ACR Y. THE ACR Y WAS OUT OF MY AIRSPACE HOWEVER, I DROPPED THE DATA AND NEVER PULLED IT BACK UP. I ALSO THOUGHT THE ACR Y WAS HDG TOWARD PSB. MOSTLY BECAUSE A LARGE MAJORITY OF TFC GOING TO THAT SECTOR GOES TOWARD PSB. I BELIEVE EVEN THOUGH I KNEW THE ACR Y WAS THERE THAT IF I PULLED UP DATA BLOCK AGAIN EVEN THOUGH HE WAS OUT OF MY AIRSPACE, I WOULD HAVE BEEN MORE HESITANT TO DSND ACR X JET.

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.