Narrative:

During climb out from seatac en route to pasc, wa, the first officer was flying and I was performing PNF duties. Departure was working numerous aircraft and was extremely busy. Sea departure controller instructed us to expedite climb to 13000 ft for traffic. Approximately 5 mins later sea departure gave us a heading to reintercept the airway (085 degree radial sea VOR) and resume own navigation. Shortly after intercepting the airway, sea departure instructed us to turn to heading 040 degrees, climb to 15000 ft and contact ZSE. The first officer, who was flying, began to comply with the instructions. I switched to ZSE frequency and called sea informing the controller that we were climbing to 15000 ft and turning to heading 040 degree assigned. The turn seemed funny to me, however, we had been turned once already for traffic. ZSE's response to the heading was 'negative' and he then turned us back to reintercept the airway. I then explained that sea departure gave us the turn. ZSE called back a few mins later and said that sea departure gave the 040 degree heading to a company flight #xyz, our flight was #yxz , who was also eastbound being worked on the same departure frequency. I know sea departure gave us, flight yxz, the turn to 040 degrees and not the company flight xyz, because we were given ZSE frequency 120.3. Company flight xyz would have received ZSE frequency 135.52 for direction of flight and destination. I believe that the sea departure controller was extremely busy at the time and he honestly confused our flight numbers xyz-yxz. In retrospect, I should have questioned the instruction to turn to heading 040 degrees, especially because the heading change was given and then a handoff to ZSE with no clarification as to what the heading was for, traffic, terrain, etc.

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Original NASA ASRS Text

Title: HDG DEV - FLC OR ATC?

Narrative: DURING CLBOUT FROM SEATAC ENRTE TO PASC, WA, THE FO WAS FLYING AND I WAS PERFORMING PNF DUTIES. DEP WAS WORKING NUMEROUS ACFT AND WAS EXTREMELY BUSY. SEA DEP CTLR INSTRUCTED US TO EXPEDITE CLB TO 13000 FT FOR TFC. APPROX 5 MINS LATER SEA DEP GAVE US A HDG TO REINTERCEPT THE AIRWAY (085 DEG RADIAL SEA VOR) AND RESUME OWN NAV. SHORTLY AFTER INTERCEPTING THE AIRWAY, SEA DEP INSTRUCTED US TO TURN TO HDG 040 DEGS, CLB TO 15000 FT AND CONTACT ZSE. THE FO, WHO WAS FLYING, BEGAN TO COMPLY WITH THE INSTRUCTIONS. I SWITCHED TO ZSE FREQ AND CALLED SEA INFORMING THE CTLR THAT WE WERE CLBING TO 15000 FT AND TURNING TO HDG 040 DEG ASSIGNED. THE TURN SEEMED FUNNY TO ME, HOWEVER, WE HAD BEEN TURNED ONCE ALREADY FOR TFC. ZSE'S RESPONSE TO THE HDG WAS 'NEGATIVE' AND HE THEN TURNED US BACK TO REINTERCEPT THE AIRWAY. I THEN EXPLAINED THAT SEA DEP GAVE US THE TURN. ZSE CALLED BACK A FEW MINS LATER AND SAID THAT SEA DEP GAVE THE 040 DEG HDG TO A COMPANY FLIGHT #XYZ, OUR FLT WAS #YXZ , WHO WAS ALSO EBOUND BEING WORKED ON THE SAME DEP FREQ. I KNOW SEA DEP GAVE US, FLT YXZ, THE TURN TO 040 DEGS AND NOT THE COMPANY FLT XYZ, BECAUSE WE WERE GIVEN ZSE FREQ 120.3. COMPANY FLT XYZ WOULD HAVE RECEIVED ZSE FREQ 135.52 FOR DIRECTION OF FLT AND DEST. I BELIEVE THAT THE SEA DEP CTLR WAS EXTREMELY BUSY AT THE TIME AND HE HONESTLY CONFUSED OUR FLIGHT NUMBERS XYZ-YXZ. IN RETROSPECT, I SHOULD HAVE QUESTIONED THE INSTRUCTION TO TURN TO HDG 040 DEGS, ESPECIALLY BECAUSE THE HDG CHANGE WAS GIVEN AND THEN A HDOF TO ZSE WITH NO CLARIFICATION AS TO WHAT THE HDG WAS FOR, TFC, TERRAIN, ETC.

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.