B737-400 flight crew climbs above assigned altitude.

Attributes
ACN	379740
Time
Date	199709
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : nfd
State Reference	CT
Altitude	msl bound lower : 24000 msl bound upper : 26000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw
Operator	common carrier : air carrier
Make Model Name	B737-400
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 80 flight time total : 10000 flight time type : 3000
ASRS Report	379740
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : overshoot non adherence : far non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We believed we were cleared to FL260 when a controller said we were only cleared to FL240.

Original NASA ASRS Text

Title: B737-400 FLC CLBS ABOVE ASSIGNED ALT.

Narrative: WE BELIEVED WE WERE CLRED TO FL260 WHEN A CTLR SAID WE WERE ONLY CLRED TO FL240.

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.