ZBW controller experienced operational error at FL240.

Attributes
ACN	610566
Time
Date	200401
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : ctr.vor
State Reference	MA
Altitude	msl bound lower : 24000 msl bound upper : 24100
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw.artcc artcc : zny.artcc
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude climbout : vacating altitude
Aircraft 2
Controlling Facilities	artcc : zbw.artcc
Operator	common carrier : air carrier
Make Model Name	Regional Jet CL65, Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude climbout : vacating altitude
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 12
ASRS Report	610566
Person 2
Affiliation	government : faa
Function	controller : handoff position
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	atc equipment : conflict alert other controllera
Resolutory Action	controller : issued advisory flight crew : took evasive action
Consequence	faa : investigated
Miss Distance	horizontal : 22800
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

The northbound crj, which has a notoriously slow climb rate, checked in climbing to an altitude not reflected in the data block. The readback was not caught by me and the erroneous data block not caught by handoff sector. I witnessed FL241 in data block and climbed B757 using observed leaving rule. Separation was lost.

Original NASA ASRS Text

Title: ZBW CTLR EXPERIENCED OPERROR AT FL240.

Narrative: THE NBOUND CRJ, WHICH HAS A NOTORIOUSLY SLOW CLB RATE, CHKED IN CLBING TO AN ALT NOT REFLECTED IN THE DATA BLOCK. THE READBACK WAS NOT CAUGHT BY ME AND THE ERRONEOUS DATA BLOCK NOT CAUGHT BY HDOF SECTOR. I WITNESSED FL241 IN DATA BLOCK AND CLBED B757 USING OBSERVED LEAVING RULE. SEPARATION WAS LOST.

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.