An air carrier FK10 flight crew leveled at 13000 ft when the clearance was for FL230. No conflict.

Attributes
ACN	401159
Time
Date	199804
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ord
State Reference	IL
Altitude	msl bound lower : 13000 msl bound upper : 23000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau tower : sjc
Operator	common carrier : air carrier
Make Model Name	Fokker 100
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
ASRS Report	401159
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	401160
Events
Anomaly	altitude deviation : undershoot non adherence : far non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

After leveling at 13000 ft ATC advised we had been given FL230. Climb to FL230 and noted no traffic conflicts. We believed we had been given 13000 ft and read it back as such. ATC was not worried and flight went on as normal.

Original NASA ASRS Text

Title: AN ACR FK10 FLC LEVELED AT 13000 FT WHEN THE CLRNC WAS FOR FL230. NO CONFLICT.

Narrative: AFTER LEVELING AT 13000 FT ATC ADVISED WE HAD BEEN GIVEN FL230. CLB TO FL230 AND NOTED NO TFC CONFLICTS. WE BELIEVED WE HAD BEEN GIVEN 13000 FT AND READ IT BACK AS SUCH. ATC WAS NOT WORRIED AND FLT WENT ON AS NORMAL.

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.