Narrative:

Dfw SID calls for climb to 10,000'. After leveling at 10,000' in the clear and accelerating to climb speed of 320 KTS, departure called traffic crossing left to right at 11,000'. We acknowledged crossing traffic. As crossing traffic passed in front of us, clearance was given to climb to 17,000'. We acknowledged this and began climb to 17,000'. Out of 10,200' another aircraft informed departure control that we had taken their clearance. I began to make immediate corrective action to return to 10,000'. We topped out at 10,400 and were descending through 10,200 when departure asked for our altitude. Problems that contributed to this include similar flight numbers. Ours was abz, the other aircraft was xyz. Also, we were in the normal position to have received that clearance. Apparently because of the workload xyz received their clearance late. There was no other conversation in the cockpit that could have distracted us from listening for proper flight number. A more critical ear would have prevented this incident. Supplemental information from acn 131296: we were given clearance to climb to 17,000' and we read back the clearance to climb. We commented to ourselves that it seemed an unusually close clearance between aircraft since we just had an medium large transport pass us overhead at 11,000' inbound to dfw.

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Original NASA ASRS Text

Title: ALT EXCURSION. MIXUP ON SIMILAR SOUNDING FLT NUMBERS IS CITED BY REPORTER.

Narrative: DFW SID CALLS FOR CLIMB TO 10,000'. AFTER LEVELING AT 10,000' IN THE CLEAR AND ACCELERATING TO CLIMB SPEED OF 320 KTS, DEP CALLED TFC XING LEFT TO RIGHT AT 11,000'. WE ACKNOWLEDGED XING TFC. AS XING TFC PASSED IN FRONT OF US, CLRNC WAS GIVEN TO CLIMB TO 17,000'. WE ACKNOWLEDGED THIS AND BEGAN CLIMB TO 17,000'. OUT OF 10,200' ANOTHER ACFT INFORMED DEP CTL THAT WE HAD TAKEN THEIR CLRNC. I BEGAN TO MAKE IMMEDIATE CORRECTIVE ACTION TO RETURN TO 10,000'. WE TOPPED OUT AT 10,400 AND WERE DESCENDING THROUGH 10,200 WHEN DEP ASKED FOR OUR ALT. PROBLEMS THAT CONTRIBUTED TO THIS INCLUDE SIMILAR FLT NUMBERS. OURS WAS ABZ, THE OTHER ACFT WAS XYZ. ALSO, WE WERE IN THE NORMAL POSITION TO HAVE RECEIVED THAT CLRNC. APPARENTLY BECAUSE OF THE WORKLOAD XYZ RECEIVED THEIR CLRNC LATE. THERE WAS NO OTHER CONVERSATION IN THE COCKPIT THAT COULD HAVE DISTRACTED US FROM LISTENING FOR PROPER FLT NUMBER. A MORE CRITICAL EAR WOULD HAVE PREVENTED THIS INCIDENT. SUPPLEMENTAL INFORMATION FROM ACN 131296: WE WERE GIVEN CLRNC TO CLIMB TO 17,000' AND WE READ BACK THE CLRNC TO CLIMB. WE COMMENTED TO OURSELVES THAT IT SEEMED AN UNUSUALLY CLOSE CLRNC BETWEEN ACFT SINCE WE JUST HAD AN MLG PASS US OVERHEAD AT 11,000' INBND TO DFW.

Data retrieved from NASA's ASRS site as of August 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.