Narrative:

Not long after checking in with gso approach, we apparently understood a clearance given to another aircraft was intended for us. The first officer read back the clearance (the exact clearance I do not remember) and the controller said 2 aircraft answered the clearance, and reissued the clearance to an air carrier aircraft, flight XXX. I did not immediately notice the similarity between the call sign/flight numbers of the air carrier XXX and ours (air carrier 2 axxx). Apparently, the controller did not realize that the call signs, when spoken, sound almost identical, because he did not alert us of that fact. We continued on our assigned heading (downwind runway 32 at gso) and altitude (4000 ft MSL). The approach controller then advised that we were downwind runway 32. A few moments went by, then we received from the approach what we interpreted as clearance for a visual approach for runway 32. My first officer read back the clearance, and I began descent to 3000 ft AGL and initiated an approximately 20 degree right turn to begin turn to base. The approach controller then advised us that we should be on a heading of xx degrees and 4000 ft. I immediately corrected heading and altitude and began to question the communication error. I heard the visual approach clearance repeated. I then realized the similarity between the 2 call signs. Conclusion: reviewing the situation, I can conclude that all 3 parties -- my first officer and I, air carrier XXX, and the approach controller, at some points during this time period, misinterped clrncs and/or readbacks of those clrncs due to the similar sounding call signs: air carrier XXX and air carrier 2 axxx. The controller was the party to first receive information and had knowledge of the similar call signs, but failed to alert the 2 flcs. Contributing factors are the high workload of the controller and flcs during this critical phase of flight, ie, reciting checklists, looking for traffic, scanning outside to locate the airport visually.

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Original NASA ASRS Text

Title: DC9 CREW WITH SIMILAR CALL SIGN TRIES TO SORT OUT CLRNCS BTWN CTLRS AND OTHER FLCS AS MULTIPLE CLRNCS ARE GIVEN AND RECEIVED BY WRONG CREW.

Narrative: NOT LONG AFTER CHKING IN WITH GSO APCH, WE APPARENTLY UNDERSTOOD A CLRNC GIVEN TO ANOTHER ACFT WAS INTENDED FOR US. THE FO READ BACK THE CLRNC (THE EXACT CLRNC I DO NOT REMEMBER) AND THE CTLR SAID 2 ACFT ANSWERED THE CLRNC, AND REISSUED THE CLRNC TO AN ACR ACFT, FLT XXX. I DID NOT IMMEDIATELY NOTICE THE SIMILARITY BTWN THE CALL SIGN/FLT NUMBERS OF THE ACR XXX AND OURS (ACR 2 AXXX). APPARENTLY, THE CTLR DID NOT REALIZE THAT THE CALL SIGNS, WHEN SPOKEN, SOUND ALMOST IDENTICAL, BECAUSE HE DID NOT ALERT US OF THAT FACT. WE CONTINUED ON OUR ASSIGNED HDG (DOWNWIND RWY 32 AT GSO) AND ALT (4000 FT MSL). THE APCH CTLR THEN ADVISED THAT WE WERE DOWNWIND RWY 32. A FEW MOMENTS WENT BY, THEN WE RECEIVED FROM THE APCH WHAT WE INTERPED AS CLRNC FOR A VISUAL APCH FOR RWY 32. MY FO READ BACK THE CLRNC, AND I BEGAN DSCNT TO 3000 FT AGL AND INITIATED AN APPROX 20 DEG R TURN TO BEGIN TURN TO BASE. THE APCH CTLR THEN ADVISED US THAT WE SHOULD BE ON A HDG OF XX DEGS AND 4000 FT. I IMMEDIATELY CORRECTED HDG AND ALT AND BEGAN TO QUESTION THE COM ERROR. I HEARD THE VISUAL APCH CLRNC REPEATED. I THEN REALIZED THE SIMILARITY BTWN THE 2 CALL SIGNS. CONCLUSION: REVIEWING THE SIT, I CAN CONCLUDE THAT ALL 3 PARTIES -- MY FO AND I, ACR XXX, AND THE APCH CTLR, AT SOME POINTS DURING THIS TIME PERIOD, MISINTERPED CLRNCS AND/OR READBACKS OF THOSE CLRNCS DUE TO THE SIMILAR SOUNDING CALL SIGNS: ACR XXX AND ACR 2 AXXX. THE CTLR WAS THE PARTY TO FIRST RECEIVE INFO AND HAD KNOWLEDGE OF THE SIMILAR CALL SIGNS, BUT FAILED TO ALERT THE 2 FLCS. CONTRIBUTING FACTORS ARE THE HIGH WORKLOAD OF THE CTLR AND FLCS DURING THIS CRITICAL PHASE OF FLT, IE, RECITING CHKLISTS, LOOKING FOR TFC, SCANNING OUTSIDE TO LOCATE THE ARPT VISUALLY.

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.