Narrative:

Checked in with approach control as air carrier X. Was told to descend and maintain 5000 ft, which I expected to get as we were at 10000 ft. Started our descent and at about 7200 ft approach told us to stop our descent at 7000 ft. That's fine. But then he asked what was our assigned altitude. I told him 5000 ft. He said we were given 8000 ft and the 5000 ft was for another aircraft. At this time he told us that there was another aircraft with a similar call sign. Their call sign was air carrier Y who was also on frequency. We were not aware of another aircraft with such a close call sign. 3 of us in the cockpit heard the same thing. We only heard air carrier X and I read back the 5000 ft as air carrier X, maintain 5000 ft. He also warned air carrier Y of the situation as they had answered for us also. We both became aware of this and were aware of it as we switched through 3 more frequencys until we landed. Our actual flight number was air carrier X, but on this flight for ATC was cut to just air carrier X. The jets use the 4 letters and we in the dash use just 3 letters. Gets a little confusing and we must stay alert. But we also need to know if similar call signs are out there as some xmissions get clipped at the very start it seems.

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Original NASA ASRS Text

Title: FLC OF A DEHAVILLAND DASH 8 MISTAKENLY TOOK THE CLRNC FOR ANOTHER ACFT OF A SIMILAR CALL SIGN AND DSNDED BELOW ASSIGNED.

Narrative: CHKED IN WITH APCH CTL AS ACR X. WAS TOLD TO DSND AND MAINTAIN 5000 FT, WHICH I EXPECTED TO GET AS WE WERE AT 10000 FT. STARTED OUR DSCNT AND AT ABOUT 7200 FT APCH TOLD US TO STOP OUR DSCNT AT 7000 FT. THAT'S FINE. BUT THEN HE ASKED WHAT WAS OUR ASSIGNED ALT. I TOLD HIM 5000 FT. HE SAID WE WERE GIVEN 8000 FT AND THE 5000 FT WAS FOR ANOTHER ACFT. AT THIS TIME HE TOLD US THAT THERE WAS ANOTHER ACFT WITH A SIMILAR CALL SIGN. THEIR CALL SIGN WAS ACR Y WHO WAS ALSO ON FREQ. WE WERE NOT AWARE OF ANOTHER ACFT WITH SUCH A CLOSE CALL SIGN. 3 OF US IN THE COCKPIT HEARD THE SAME THING. WE ONLY HEARD ACR X AND I READ BACK THE 5000 FT AS ACR X, MAINTAIN 5000 FT. HE ALSO WARNED ACR Y OF THE SIT AS THEY HAD ANSWERED FOR US ALSO. WE BOTH BECAME AWARE OF THIS AND WERE AWARE OF IT AS WE SWITCHED THROUGH 3 MORE FREQS UNTIL WE LANDED. OUR ACTUAL FLT NUMBER WAS ACR X, BUT ON THIS FLT FOR ATC WAS CUT TO JUST ACR X. THE JETS USE THE 4 LETTERS AND WE IN THE DASH USE JUST 3 LETTERS. GETS A LITTLE CONFUSING AND WE MUST STAY ALERT. BUT WE ALSO NEED TO KNOW IF SIMILAR CALL SIGNS ARE OUT THERE AS SOME XMISSIONS GET CLIPPED AT THE VERY START IT SEEMS.

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.