Widebody Transport
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 155
Communication Breakdown; Confusion
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors; Procedure
We were in the descent after completing the redeye to LEBL. The sun had been up for two hours as we descended into Spain. I was the Relief Pilot and both the Captain (pilot monitoring) and FO (pilot flying) had been in their seats for 30 minutes. ATIS was calling Runway 07 active and when the Captain checked in with ATC; they informed him to expect Runway 25R and the LOBAR 1W; SLL transition. The Captain confirmed with ATC that we could expect the ILS Z Runway 25R. On that approach plate; SLL is an IAF. All three of us assumed that meant to fly the LOBAR 1W STAR to SLL and then follow the approach. After heading 130 degrees out of SLL for about 30 seconds; ATC asked where we were going; then proceeded to tell us that we didn't have clearance to proceed towards the approach course. Never were we given holding instructions; told to expect to hold; or told that we had a clearance limit. We heard LOBAR 1W SLL transition and the ILS Z 25R. There were no RAs (Resolution Advisories) or TAs (Traffic Advisories) nor were any other aircraft vectored due to our continuing on the course. We did not leave FL100 at any time until later cleared during the commencement of the approach vectoring. ATC advised the Captain that they were going to file a report and suggested the same.
Air carrier Relief pilot reported the flight crew experienced a track deviation after they misinterpreted an ATC clearance on arrival into LEBL.