Narrative:

Our flight call sign was aircraft xyz. During taxi out, we heard aircraft yxz on frequency and noted that it was just ahead of us. My first officer and I were trying to be very aware of who the controllers were talking to. We had leveled off at 10000 ft and I believe we had just been handed off to cleveland 132.45. Both aircraft were headed to the same destination. We were cleared to 13000 ft. We confirmed with each other that the assignment was for us, then read it back. Aircraft yxz responded to a subsequent call that was for us and then things got very confused as to exactly who cle was talking to. Passing 10300 ft, we asked for verification of our altitude assignment and we heard 'aircraft xyz cleared to 13000 ft.' at 10200 ft, there was still confusion between us, cleveland, and aircraft yxz as to who was supposed to be at 10000 ft and who was supposed to be at 13000 ft. Again, aircraft yxz responded to a call for us. In the middle of all this, we noticed 2 visual targets -- 10 O'clock position and 11:30 O'clock position, 1000 ft above. TCASII showed the range to be greater than 2 mi and passing to the side. In retrospect, I don't think cleveland had a heads up that the 2 similar call signs were so close.

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Original NASA ASRS Text

Title: SIMILAR CALL SIGNS CREATE A CONFUSING SIT WHEN, APPARENTLY, THE SIMILAR SIGNS WERE NOT NOTICED BY THE CTLR.

Narrative: OUR FLT CALL SIGN WAS ACFT XYZ. DURING TAXI OUT, WE HEARD ACFT YXZ ON FREQ AND NOTED THAT IT WAS JUST AHEAD OF US. MY FO AND I WERE TRYING TO BE VERY AWARE OF WHO THE CTLRS WERE TALKING TO. WE HAD LEVELED OFF AT 10000 FT AND I BELIEVE WE HAD JUST BEEN HANDED OFF TO CLEVELAND 132.45. BOTH ACFT WERE HEADED TO THE SAME DEST. WE WERE CLRED TO 13000 FT. WE CONFIRMED WITH EACH OTHER THAT THE ASSIGNMENT WAS FOR US, THEN READ IT BACK. ACFT YXZ RESPONDED TO A SUBSEQUENT CALL THAT WAS FOR US AND THEN THINGS GOT VERY CONFUSED AS TO EXACTLY WHO CLE WAS TALKING TO. PASSING 10300 FT, WE ASKED FOR VERIFICATION OF OUR ALT ASSIGNMENT AND WE HEARD 'ACFT XYZ CLRED TO 13000 FT.' AT 10200 FT, THERE WAS STILL CONFUSION BTWN US, CLEVELAND, AND ACFT YXZ AS TO WHO WAS SUPPOSED TO BE AT 10000 FT AND WHO WAS SUPPOSED TO BE AT 13000 FT. AGAIN, ACFT YXZ RESPONDED TO A CALL FOR US. IN THE MIDDLE OF ALL THIS, WE NOTICED 2 VISUAL TARGETS -- 10 O'CLOCK POS AND 11:30 O'CLOCK POS, 1000 FT ABOVE. TCASII SHOWED THE RANGE TO BE GREATER THAN 2 MI AND PASSING TO THE SIDE. IN RETROSPECT, I DON'T THINK CLEVELAND HAD A HEADS UP THAT THE 2 SIMILAR CALL SIGNS WERE SO CLOSE.

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.