Flight crew inbound to dfw descends without ATC clearance.

Attributes
ACN	573097
Time
Date	200302
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dfw.airport
State Reference	TX
Altitude	msl bound lower : 10500 msl bound upper : 11000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : d10.tracon tower : ewr.tower
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : d10.tracon
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	573097
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : far non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : returned to assigned altitude
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

On approach into dfw, an air carrier X flight with a similar call sign, was also on frequency. We were given clearance to descend to 4000 ft from 11000 ft. Frequency was then changed to 133.15. After switching frequencys, we were told we had taken the clearance for the other flight. We feel certain our readback was acknowledged. Nonetheless, there was an obvious mistake made in communication. We were able to stop our descent in 500 ft. There were no traffic considerations, but it gave us pause for thought.

Original NASA ASRS Text

Title: FLC INBOUND TO DFW DSNDS WITHOUT ATC CLRNC.

Narrative: ON APCH INTO DFW, AN ACR X FLT WITH A SIMILAR CALL SIGN, WAS ALSO ON FREQ. WE WERE GIVEN CLRNC TO DSND TO 4000 FT FROM 11000 FT. FREQ WAS THEN CHANGED TO 133.15. AFTER SWITCHING FREQS, WE WERE TOLD WE HAD TAKEN THE CLRNC FOR THE OTHER FLT. WE FEEL CERTAIN OUR READBACK WAS ACKNOWLEDGED. NONETHELESS, THERE WAS AN OBVIOUS MISTAKE MADE IN COM. WE WERE ABLE TO STOP OUR DSCNT IN 500 FT. THERE WERE NO TFC CONSIDERATIONS, BUT IT GAVE US PAUSE FOR THOUGHT.

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.