Narrative:

My copilot and I (medium large transport abc) had just been clrd for takeoff from atl, runway 9L and instructed to fly heading 095 degrees. Takeoff was normal with me (captain) hand flying our medium large transport (abc). Tower instructed us to switch over to departure control. My first officer made the switch and contacted atl departure control (125.0) and checked in. 'Atl departure, medium large transport (abc) with you, 2000 climbing to 10000.' departure replied, 'roger medium large transport (abc), turn left 360 degrees.' my first officer acknowledged the turn. I immediately told my first officer that that was a strange turn for us (departing runway 9L). As I started a turn to 360 degrees, I saw there was an large transport on departure from the north runway. The large transport was off the ground, even (along side of) us but much lower. I stopped our turn at heading of 080 or 085 degrees and told my first officer of the other aircraft and asked him to verify the turn with departure. At this time, departure came back on and told us to fly the heading assigned by the tower (095 degrees), then immediately said, 'medium large transport (abc), fly heading 120 degrees, verify climbing to 10000'.' we acknowledged and I asked the first officer to fly the aircraft, that I wanted to talk to departure. Departure then told us that we had taken a turn for large transport (bbc). He then made several other transmissions. I called him and told him that I wanted to talk to him when he got a free moment. He made several other transmissions and then came back and asked what I wanted. I went over the sequence of events with him and he informed me that we had taken the call for large transport bbc and he indicated no acknowledgement of our readback. We then switched frequency and that was the end of the incident. We never came close to the other aircraft and I had visual contact until after we were heading 120 degrees. Both my first officer and I were wearing headsets and clearly heard all transmissions. I believe that when my first officer called in 'medium large transport (abc)' he programmed the controllers mind (who was getting ready to call large transport (bbc), and he subsequently gave us the turn. Supplemental information from acn 81241: I (first officer, PNF) checked in with 'departure, medium large transport (abc) 2 for 10.' departure's response was, 'medium large transport (abc) roger, turn left to 360 degrees.' I read back 'roger, medium large transport (abc) left to 360.' (we were at 1000' AGL, off the end of 9L at atl.) because of our locale the captain immediately said something like, that's a strange request, there's an airplane down there too, check and see if he really wants us to do that. During this time our heading changed only about 5 degrees, at which point the captain stopped the turn. Just at that moment and just before I had a chance to key the microphone and ask for verification of instructions, the controller transmitted to us to resume the heading that tower had give us (095 degrees) and verify that we were climbing to 10000'. At the request of the captain a conversation followed. The controller felt that we had taken a turn which was ordered to flight large transport (bbc). Both the captain and I heard (abc) and I read back 'medium large transport (abc) left to 360 degrees.' large transport (bbc) was on another frequency according to the departure controller. Perhaps when I checked in it sort of programmed the departure controller's mind to (abc) instead of (bbc). He rogered our check-in and gave the turn all in the same transmissions and under the single call sign, and he didn't catch his error. After my readback for that moment I believe he had us confused with large transport (bbc). There was no danger because the captain immediately sensed that something was not right and therefore only changed our heading about 5 degrees. Also, the airplane on the north side and abeam of us was well below us.

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Original NASA ASRS Text

Title: MLG TOOK TURN INTENDED FOR COMPANY FLT WITH SIMILAR CALL SIGN AND BOTH CTLR AND CAPT REPORTER CAUGHT PROBLEM AT SAME TIME. NO SEPARATION LOST.

Narrative: MY COPLT AND I (MLG ABC) HAD JUST BEEN CLRD FOR TKOF FROM ATL, RWY 9L AND INSTRUCTED TO FLY HDG 095 DEGS. TKOF WAS NORMAL WITH ME (CAPT) HAND FLYING OUR MLG (ABC). TWR INSTRUCTED US TO SWITCH OVER TO DEP CTL. MY F/O MADE THE SWITCH AND CONTACTED ATL DEP CTL (125.0) AND CHKED IN. 'ATL DEP, MLG (ABC) WITH YOU, 2000 CLBING TO 10000.' DEP REPLIED, 'ROGER MLG (ABC), TURN LEFT 360 DEGS.' MY F/O ACKNOWLEDGED THE TURN. I IMMEDIATELY TOLD MY F/O THAT THAT WAS A STRANGE TURN FOR US (DEPARTING RWY 9L). AS I STARTED A TURN TO 360 DEGS, I SAW THERE WAS AN LGT ON DEP FROM THE N RWY. THE LGT WAS OFF THE GND, EVEN (ALONG SIDE OF) US BUT MUCH LOWER. I STOPPED OUR TURN AT HDG OF 080 OR 085 DEGS AND TOLD MY F/O OF THE OTHER ACFT AND ASKED HIM TO VERIFY THE TURN WITH DEP. AT THIS TIME, DEP CAME BACK ON AND TOLD US TO FLY THE HDG ASSIGNED BY THE TWR (095 DEGS), THEN IMMEDIATELY SAID, 'MLG (ABC), FLY HDG 120 DEGS, VERIFY CLBING TO 10000'.' WE ACKNOWLEDGED AND I ASKED THE F/O TO FLY THE ACFT, THAT I WANTED TO TALK TO DEP. DEP THEN TOLD US THAT WE HAD TAKEN A TURN FOR LGT (BBC). HE THEN MADE SEVERAL OTHER TRANSMISSIONS. I CALLED HIM AND TOLD HIM THAT I WANTED TO TALK TO HIM WHEN HE GOT A FREE MOMENT. HE MADE SEVERAL OTHER TRANSMISSIONS AND THEN CAME BACK AND ASKED WHAT I WANTED. I WENT OVER THE SEQUENCE OF EVENTS WITH HIM AND HE INFORMED ME THAT WE HAD TAKEN THE CALL FOR LGT BBC AND HE INDICATED NO ACKNOWLEDGEMENT OF OUR READBACK. WE THEN SWITCHED FREQ AND THAT WAS THE END OF THE INCIDENT. WE NEVER CAME CLOSE TO THE OTHER ACFT AND I HAD VISUAL CONTACT UNTIL AFTER WE WERE HDG 120 DEGS. BOTH MY F/O AND I WERE WEARING HEADSETS AND CLEARLY HEARD ALL TRANSMISSIONS. I BELIEVE THAT WHEN MY F/O CALLED IN 'MLG (ABC)' HE PROGRAMMED THE CTLRS MIND (WHO WAS GETTING READY TO CALL LGT (BBC), AND HE SUBSEQUENTLY GAVE US THE TURN. SUPPLEMENTAL INFO FROM ACN 81241: I (F/O, PNF) CHKED IN WITH 'DEP, MLG (ABC) 2 FOR 10.' DEP'S RESPONSE WAS, 'MLG (ABC) ROGER, TURN LEFT TO 360 DEGS.' I READ BACK 'ROGER, MLG (ABC) LEFT TO 360.' (WE WERE AT 1000' AGL, OFF THE END OF 9L AT ATL.) BECAUSE OF OUR LOCALE THE CAPT IMMEDIATELY SAID SOMETHING LIKE, THAT'S A STRANGE REQUEST, THERE'S AN AIRPLANE DOWN THERE TOO, CHK AND SEE IF HE REALLY WANTS US TO DO THAT. DURING THIS TIME OUR HDG CHANGED ONLY ABOUT 5 DEGS, AT WHICH POINT THE CAPT STOPPED THE TURN. JUST AT THAT MOMENT AND JUST BEFORE I HAD A CHANCE TO KEY THE MIC AND ASK FOR VERIFICATION OF INSTRUCTIONS, THE CTLR TRANSMITTED TO US TO RESUME THE HDG THAT TWR HAD GIVE US (095 DEGS) AND VERIFY THAT WE WERE CLBING TO 10000'. AT THE REQUEST OF THE CAPT A CONVERSATION FOLLOWED. THE CTLR FELT THAT WE HAD TAKEN A TURN WHICH WAS ORDERED TO FLT LGT (BBC). BOTH THE CAPT AND I HEARD (ABC) AND I READ BACK 'MLG (ABC) LEFT TO 360 DEGS.' LGT (BBC) WAS ON ANOTHER FREQ ACCORDING TO THE DEP CTLR. PERHAPS WHEN I CHKED IN IT SORT OF PROGRAMMED THE DEP CTLR'S MIND TO (ABC) INSTEAD OF (BBC). HE ROGERED OUR CHK-IN AND GAVE THE TURN ALL IN THE SAME TRANSMISSIONS AND UNDER THE SINGLE CALL SIGN, AND HE DIDN'T CATCH HIS ERROR. AFTER MY READBACK FOR THAT MOMENT I BELIEVE HE HAD US CONFUSED WITH LGT (BBC). THERE WAS NO DANGER BECAUSE THE CAPT IMMEDIATELY SENSED THAT SOMETHING WAS NOT RIGHT AND THEREFORE ONLY CHANGED OUR HDG ABOUT 5 DEGS. ALSO, THE AIRPLANE ON THE N SIDE AND ABEAM OF US WAS WELL BELOW US.

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.