A flight crew flew a clearance intended for another aircraft with a similar call sign near ord.

Attributes
ACN	443543
Time
Date	199907
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	msl bound lower : 6000 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : enroute altitude change
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 250 flight time total : 25000 flight time type : 4000
ASRS Report	443543
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : multi engine pilot : commercial pilot : atp
Experience	flight time last 90 days : 200 flight time total : 6500 flight time type : 200
ASRS Report	442799
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On approach control direct ord working ord approach, landing east. 4 flts X, Y, and Z, all with similar call signs, ie, flight numbers took altitude and read back altitude and approach control after approximately 7 mins had us turn to 090 degrees and climb up to 7000 ft but there was no conflict. Appears to be mix up between the 4 flts which all had similar flight numbers.

Original NASA ASRS Text

Title: A FLC FLEW A CLRNC INTENDED FOR ANOTHER ACFT WITH A SIMILAR CALL SIGN NEAR ORD.

Narrative: ON APCH CTL DIRECT ORD WORKING ORD APCH, LNDG E. 4 FLTS X, Y, AND Z, ALL WITH SIMILAR CALL SIGNS, IE, FLT NUMBERS TOOK ALT AND READ BACK ALT AND APCH CTL AFTER APPROX 7 MINS HAD US TURN TO 090 DEGS AND CLB UP TO 7000 FT BUT THERE WAS NO CONFLICT. APPEARS TO BE MIX UP BTWN THE 4 FLTS WHICH ALL HAD SIMILAR FLT NUMBERS.

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.