Narrative:

Copilot flying, departing lax runway 24L. Clearance was fly 250 degrees, climb to 2000'. Tower switched us over to departure and I think the communication was as follows: 'air carrier X climbing to 2 out of 1300.' departure: 'was that air carrier X?' 'affirmative, climbing to 2 out of 1500.' departure: 'air carrier, climb to 3000'.' acknowledged. Departure: 'turn left to 090 degrees.' air carrier X: 'left turn 090 degrees.' at about 2000' MSL we broke through the overcast and became VFR. I observed a large transport Y off of the 25 runways. It was obvious that this was a conflict and that had we been IFR it would have been a very dangerous situation--very dangerous. I could see that the large transport Y was outclbing us and that our turning radius would take us behind him. Departure control then came on, asked our heading. I told him we had been told to turn to 090 degrees and he said no we hadn't, 'maintain 2500' and turn to a westerly heading and maintain visibility sep on large transport Y.' the controller who corrected the situation was different than the original controller. After the evasive action all was normal. As a long time read of 'call back,' I am very aware of hearback problems. I make a concerted effort to communicate in a clear and concise manner, always using the airline identify. I was aware when we received the turn to 090 degrees that I had not heard the airline identify, but the readback was not blocked or impeded in any other way. Thus, when I was not correct, I assumed that it was definitely our clearance. I should have known better, as the turn was much earlier than normal and would have caused problems with altitude compliance on the SID. The very first transmission I heard when switching from tower to departure was someone else telling someone else that they had done a good job. That should have been a key that things were not going too well with departure. My initial call up to departure was not as smooth as it could have been. I was concerned with stopping the climb at 2000'. I called lax departure on arrival at msp. They said the turn was for an air carrier Z flight.

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Original NASA ASRS Text

Title: ACR LGT TRACK HEADING DEVIATION IN RESPONSE TO WRONG CALL SIGN.

Narrative: COPLT FLYING, DEPARTING LAX RWY 24L. CLRNC WAS FLY 250 DEGS, CLB TO 2000'. TWR SWITCHED US OVER TO DEP AND I THINK THE COM WAS AS FOLLOWS: 'ACR X CLBING TO 2 OUT OF 1300.' DEP: 'WAS THAT ACR X?' 'AFFIRMATIVE, CLBING TO 2 OUT OF 1500.' DEP: 'ACR, CLB TO 3000'.' ACKNOWLEDGED. DEP: 'TURN LEFT TO 090 DEGS.' ACR X: 'LEFT TURN 090 DEGS.' AT ABOUT 2000' MSL WE BROKE THROUGH THE OVCST AND BECAME VFR. I OBSERVED A LGT Y OFF OF THE 25 RWYS. IT WAS OBVIOUS THAT THIS WAS A CONFLICT AND THAT HAD WE BEEN IFR IT WOULD HAVE BEEN A VERY DANGEROUS SITUATION--VERY DANGEROUS. I COULD SEE THAT THE LGT Y WAS OUTCLBING US AND THAT OUR TURNING RADIUS WOULD TAKE US BEHIND HIM. DEP CTL THEN CAME ON, ASKED OUR HDG. I TOLD HIM WE HAD BEEN TOLD TO TURN TO 090 DEGS AND HE SAID NO WE HADN'T, 'MAINTAIN 2500' AND TURN TO A WESTERLY HDG AND MAINTAIN VIS SEP ON LGT Y.' THE CTLR WHO CORRECTED THE SITUATION WAS DIFFERENT THAN THE ORIGINAL CTLR. AFTER THE EVASIVE ACTION ALL WAS NORMAL. AS A LONG TIME READ OF 'CALL BACK,' I AM VERY AWARE OF HEARBACK PROBS. I MAKE A CONCERTED EFFORT TO COMMUNICATE IN A CLR AND CONCISE MANNER, ALWAYS USING THE AIRLINE IDENT. I WAS AWARE WHEN WE RECEIVED THE TURN TO 090 DEGS THAT I HAD NOT HEARD THE AIRLINE IDENT, BUT THE READBACK WAS NOT BLOCKED OR IMPEDED IN ANY OTHER WAY. THUS, WHEN I WAS NOT CORRECT, I ASSUMED THAT IT WAS DEFINITELY OUR CLRNC. I SHOULD HAVE KNOWN BETTER, AS THE TURN WAS MUCH EARLIER THAN NORMAL AND WOULD HAVE CAUSED PROBS WITH ALT COMPLIANCE ON THE SID. THE VERY FIRST XMISSION I HEARD WHEN SWITCHING FROM TWR TO DEP WAS SOMEONE ELSE TELLING SOMEONE ELSE THAT THEY HAD DONE A GOOD JOB. THAT SHOULD HAVE BEEN A KEY THAT THINGS WERE NOT GOING TOO WELL WITH DEP. MY INITIAL CALL UP TO DEP WAS NOT AS SMOOTH AS IT COULD HAVE BEEN. I WAS CONCERNED WITH STOPPING THE CLB AT 2000'. I CALLED LAX DEP ON ARR AT MSP. THEY SAID THE TURN WAS FOR AN ACR Z FLT.

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.