Narrative:

On flight xyz from sps to dfw, we were given a premature frequency change by mistake from 125.8 to 132.1. Upon reaching 132.1 we heard what we thought was a heading change from 120 degrees to 100 degrees and a clearance to 3000 ft. We acknowledged and started descent. Upon reaching 4700 ft air carrier wyz called in and said we took his clearance. We immediately returned to 5000 ft and original heading. Upon verification we returned back to 125.8 on #2 VHF. Due to frequency congestion we received and accepted someone else's clearance. Better crew management and attention to the radio will prevent us from deviating again.

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Original NASA ASRS Text

Title: ERROR ADMITTED BY RPTR IN ALT DEV ALT EXCURSION AT LTT CLRNC INTERP IS INVOLVED WITH SIMILAR SOUNDING CALL SIGN A/N.

Narrative: ON FLT XYZ FROM SPS TO DFW, WE WERE GIVEN A PREMATURE FREQ CHANGE BY MISTAKE FROM 125.8 TO 132.1. UPON REACHING 132.1 WE HEARD WHAT WE THOUGHT WAS A HDG CHANGE FROM 120 DEGS TO 100 DEGS AND A CLRNC TO 3000 FT. WE ACKNOWLEDGED AND STARTED DSCNT. UPON REACHING 4700 FT ACR WYZ CALLED IN AND SAID WE TOOK HIS CLRNC. WE IMMEDIATELY RETURNED TO 5000 FT AND ORIGINAL HDG. UPON VERIFICATION WE RETURNED BACK TO 125.8 ON #2 VHF. DUE TO FREQ CONGESTION WE RECEIVED AND ACCEPTED SOMEONE ELSE'S CLRNC. BETTER CREW MGMNT AND ATTN TO THE RADIO WILL PREVENT US FROM DEVIATING AGAIN.

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.