Narrative:

First officer (reporter) was PF. On high left downwind to runway 27L at atl, we were 9 mi east of the runway when I thought I heard the captain accept the clearance 'air carrier zyx, turn left heading 360 degrees.' this would have been a base turn, and was what we were both expecting (our assigned heading prior to this was 090 degrees). I was hand flying and began a turn to the left to 360 degrees. After approximately 10 seconds on the heading 360 degrees, the approach controller said, 'air carrier zyx, your heading should be 090 degrees, turn right heading 100 degrees, descend and maintain 3500 ft.' I quickly initiated the turn back to the right. No conflict resulted, and the TCASII never issued any traffic warnings. Both the captain and I thought we had heard our call sign, but the controller said he had been talking to a 'yzx,' not 'zyx.' we have both encountered and been subject to this type of audio-dyslexia before. However, in this case, we think the controller had misspoke. Contributing factors were: 1) this was the last leg of a 4 day trip, and both the captain and first officer had tight connecting flight times to commute back to their homes. Both were in a hurry to get to atl. 2) it was the usual place for a base turn to occur. 3) the frequency was very busy, and when the captain acknowledged the clearance, he could have been stepped on by the proper aircraft acknowledging the clearance. 4) similar call signs on same frequency without either crew being told. In the future, we will pay closer attention when other aircraft with similar call signs are on the same frequency. Sometimes the controllers will bring this to our attention, other times they will not.

Related reports:

Google
 

Original NASA ASRS Text

Title: DC9 CREW ACCEPTED CLRNC FOR OTHER ACFT.

Narrative: FO (RPTR) WAS PF. ON HIGH L DOWNWIND TO RWY 27L AT ATL, WE WERE 9 MI E OF THE RWY WHEN I THOUGHT I HEARD THE CAPT ACCEPT THE CLRNC 'ACR ZYX, TURN L HDG 360 DEGS.' THIS WOULD HAVE BEEN A BASE TURN, AND WAS WHAT WE WERE BOTH EXPECTING (OUR ASSIGNED HDG PRIOR TO THIS WAS 090 DEGS). I WAS HAND FLYING AND BEGAN A TURN TO THE L TO 360 DEGS. AFTER APPROX 10 SECONDS ON THE HDG 360 DEGS, THE APCH CTLR SAID, 'ACR ZYX, YOUR HDG SHOULD BE 090 DEGS, TURN R HDG 100 DEGS, DSND AND MAINTAIN 3500 FT.' I QUICKLY INITIATED THE TURN BACK TO THE R. NO CONFLICT RESULTED, AND THE TCASII NEVER ISSUED ANY TFC WARNINGS. BOTH THE CAPT AND I THOUGHT WE HAD HEARD OUR CALL SIGN, BUT THE CTLR SAID HE HAD BEEN TALKING TO A 'YZX,' NOT 'ZYX.' WE HAVE BOTH ENCOUNTERED AND BEEN SUBJECT TO THIS TYPE OF AUDIO-DYSLEXIA BEFORE. HOWEVER, IN THIS CASE, WE THINK THE CTLR HAD MISSPOKE. CONTRIBUTING FACTORS WERE: 1) THIS WAS THE LAST LEG OF A 4 DAY TRIP, AND BOTH THE CAPT AND FO HAD TIGHT CONNECTING FLT TIMES TO COMMUTE BACK TO THEIR HOMES. BOTH WERE IN A HURRY TO GET TO ATL. 2) IT WAS THE USUAL PLACE FOR A BASE TURN TO OCCUR. 3) THE FREQ WAS VERY BUSY, AND WHEN THE CAPT ACKNOWLEDGED THE CLRNC, HE COULD HAVE BEEN STEPPED ON BY THE PROPER ACFT ACKNOWLEDGING THE CLRNC. 4) SIMILAR CALL SIGNS ON SAME FREQ WITHOUT EITHER CREW BEING TOLD. IN THE FUTURE, WE WILL PAY CLOSER ATTN WHEN OTHER ACFT WITH SIMILAR CALL SIGNS ARE ON THE SAME FREQ. SOMETIMES THE CTLRS WILL BRING THIS TO OUR ATTN, OTHER TIMES THEY WILL NOT.

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.