Altitude deviation. Answered clearance for another aircraft with same numbers.

Attributes
ACN	313320
Time
Date	199508
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : iah
State Reference	TX
Altitude	msl bound lower : 7000 msl bound upper : 8000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : iah
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : instrument pilot : atp pilot : commercial pilot : cfi
Experience	flight time last 90 days : 120 flight time total : 10000 flight time type : 5500
ASRS Report	313320
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 240 flight time total : 13000 flight time type : 8000
ASRS Report	313594
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Air carrier a XXX. Also air carrier B XXX on frequency which was unknown to us. I acknowledged clearance to descend to 3000 ft and asked for a turn from 290 degrees to 320 degrees for WX avoidance. At 7000 ft approach asked our altitude and stated we were to be at 8000 ft! Approach asked us to maintain 7000 ft and stated that the clearance to 3000 ft had been for air carrier B XXX. No conflict with traffic but thanks to an alert controller. Supplemental information from acn 313594: the controller was working 2 frequencys in a thunderstorm environment, very busy radio-wise.

Original NASA ASRS Text

Title: ALTDEV. ANSWERED CLRNC FOR ANOTHER ACFT WITH SAME NUMBERS.

Narrative: ACR A XXX. ALSO ACR B XXX ON FREQ WHICH WAS UNKNOWN TO US. I ACKNOWLEDGED CLRNC TO DSND TO 3000 FT AND ASKED FOR A TURN FROM 290 DEGS TO 320 DEGS FOR WX AVOIDANCE. AT 7000 FT APCH ASKED OUR ALT AND STATED WE WERE TO BE AT 8000 FT! APCH ASKED US TO MAINTAIN 7000 FT AND STATED THAT THE CLRNC TO 3000 FT HAD BEEN FOR ACR B XXX. NO CONFLICT WITH TFC BUT THANKS TO AN ALERT CTLR. SUPPLEMENTAL INFO FROM ACN 313594: THE CTLR WAS WORKING 2 FREQS IN A TSTM ENVIRONMENT, VERY BUSY RADIO-WISE.

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.