ZOB controller experienced operational error at FL370 when data block is dropped.

Attributes
ACN	634692
Time
Date	200410
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : slt.vortac
State Reference	PA
Altitude	msl single value : 37000
Environment
Flight Conditions	VMC
Weather Elements	Turbulence
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob.artcc tower : vny.tower
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change descent : intermediate altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zob.artcc
Operator	general aviation : corporate
Make Model Name	HS 125 Series 700
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar pilot : private pilot : instrument
Experience	controller radar : 14 controller time certified in position1 : 14 flight time total : 2450
ASRS Report	634692
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	other controllera
Resolutory Action	flight crew : took evasive action
Consequence	faa : investigated
Miss Distance	horizontal : 10800 vertical : 1100
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Aircraft X was leaving airspace swbound. I dropped data block. I then asked air carrier X if he wanted lower for chop. He said yes and I then descended him forgetting aircraft X.

Original NASA ASRS Text

Title: ZOB CTLR EXPERIENCED OPERROR AT FL370 WHEN DATA BLOCK IS DROPPED.

Narrative: ACFT X WAS LEAVING AIRSPACE SWBOUND. I DROPPED DATA BLOCK. I THEN ASKED ACR X IF HE WANTED LOWER FOR CHOP. HE SAID YES AND I THEN DSNDED HIM FORGETTING ACFT X.

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.