Altitude excursion from controller assigned.

Attributes
ACN	143819
Time
Date	199004
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ord
State Reference	IL
Altitude	msl bound lower : 10000 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other descent other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
ASRS Report	143819
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Operational Deviation Pilot Deviation

Narrative:

During descent to ord, we received and read back a clearance to 10000' MSL. As we were leveling at 10000' the controller told us to climb back to 11000' and that we had been cleared to 11000' originally. We climbed back to 11000' and the remainder of the flight was uneventful.

Original NASA ASRS Text

Title: ALT EXCURSION FROM CTLR ASSIGNED.

Narrative: DURING DSNT TO ORD, WE RECEIVED AND READ BACK A CLRNC TO 10000' MSL. AS WE WERE LEVELING AT 10000' THE CTLR TOLD US TO CLB BACK TO 11000' AND THAT WE HAD BEEN CLRED TO 11000' ORIGINALLY. WE CLBED BACK TO 11000' AND THE REMAINDER OF THE FLT WAS UNEVENTFUL.

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.