CL65 crew landing ord descended to 4000 ft and later told they should have descended to 7000 ft.

Attributes
ACN	525410
Time
Date	200109
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	msl bound lower : 6400 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zmp.artcc
Operator	common carrier : air carrier
Make Model Name	Regional Jet CL65, Undifferentiated or Other Model
Flight Phase	descent : approach descent : intermediate altitude
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : multi engine pilot : instrument pilot : cfi
Experience	flight time last 90 days : 300 flight time total : 1500 flight time type : 900
ASRS Report	525410
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : published procedure
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude none taken : detected after the fact
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

On descent into ord we were given a clearance to descend from 11000 ft MSL to 4000 ft MSL which I read back to the approach controller. Upon descending through 6400 ft MSL ATC told us that we were only cleared to 7000 ft and to begin a climb back up to 7000 ft. About that time we received a TA. The captain clicked off the autoplt and climbed the aircraft to 7000 ft. Probable cause: controller mistakenly cleared us to 4000 ft. Contributing factors: we did not query controller even though we knew that typically at that location we usually received 7000 ft instead of 4000 ft.

Original NASA ASRS Text

Title: CL65 CREW LNDG ORD DSNDED TO 4000 FT AND LATER TOLD THEY SHOULD HAVE DSNDED TO 7000 FT.

Narrative: ON DSCNT INTO ORD WE WERE GIVEN A CLRNC TO DSND FROM 11000 FT MSL TO 4000 FT MSL WHICH I READ BACK TO THE APCH CTLR. UPON DSNDING THROUGH 6400 FT MSL ATC TOLD US THAT WE WERE ONLY CLRED TO 7000 FT AND TO BEGIN A CLB BACK UP TO 7000 FT. ABOUT THAT TIME WE RECEIVED A TA. THE CAPT CLICKED OFF THE AUTOPLT AND CLBED THE ACFT TO 7000 FT. PROBABLE CAUSE: CTLR MISTAKENLY CLRED US TO 4000 FT. CONTRIBUTING FACTORS: WE DID NOT QUERY CTLR EVEN THOUGH WE KNEW THAT TYPICALLY AT THAT LOCATION WE USUALLY RECEIVED 7000 FT INSTEAD OF 4000 FT.

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.