Date: 201305
Location: EHAA.ARTCC, FO
Aircraft: B777-200
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Cruise
ATC / advisory: Center EHAA
Second aircraft: B777-200
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Confusion
Second reporter function: Pilot Not Flying; Check Pilot
Anomaly: ATC Issue All Types; Inflight Event / Encounter Other / Unknown
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented
Contributing factors: Company Policy; Human Factors; Procedure
Primary problem: Ambiguous

Narrative: Dispatch assigned two flights similar call signs (XYYX and XYYXA). These flights had the same departure airport; same destination airport; and similar routes. These two flights departed within about 30-45 minutes of one another. ATC did not like the similar call signs and asked for our flight to be re-named NXXXXX; which was also our tail number. Every controller from Germany all the way home; questioned our call sign; questioned our departure and destination airports; and wanted an explanation why our call sign was messed up. We had difficulty staying logged into CPDLC while crossing the North Atlantic. Upon reaching [our] destination; Ramp Control didn't have any idea who we were and where we were supposed to park. With a 9 hour flight time; you would think that Dispatch would have had plenty of time to notify every ARTCC and our own Ramp Operations of the call sign change.


Second narrative: On initial level off; Maastricht Center gave hand off to another Maastricht Center frequency and advised 'they have a question'. On initial check in with new frequency; we were queried on what our Aircraft registration number was. Moments later we were advised that there was a Flight XYYXA on frequency 30 minutes ahead of us with the same destination. About 3 - 5 minutes later; Maastricht told us we might have difficulty with Shanwick for crossing with CPDLC and to anticipate questions. Shortly thereafter; we were told to change our call sign on flight to our registration number; so our call sign now became 'NXXXXX' - from that point on in the flight; there were constant difficulties; and confusion regarding who we were; what we were all the way to destination- when finally [our destination] Tower did not even know what type aircraft we were. The NXXXXX was changed in the FMS so the aircraft would log onto CPDLC properly. Multiple difficulties across North Atlantic with same; both Shanwick and Gander. We did finally get logged on twice once with Shanwick and once with Gander; however were unable to log onto domestic CPDLC passing St Johns with Moncton. We informed Dispatch of the required name change with Maastricht from the start. They seemed confused by same. We were advised that usually the Alpha designation solved all these type problems; however not in this case. Multiple opportunities for missed radio calls; since every ATC agency called or referred to us as something different. All 4 pilots had difficulty with call sign at various times as well. Choose different flight numbers when two aircraft of same type are crossing in same airspace. The 'A' designation is insufficient to prevent confusion.


Synopsis: B777 flight crew reports ATC confusion when an extra flight section uses the same flight number with the addition of an Alpha; on a flight from Europe to North America.