Widebody; Low Wing; 2 Turbojet Eng
Flight Crew Last 90 Days 174; Flight Crew Total 20000; Flight Crew Type 900
Confusion; Fatigue
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Clearance
Human Factors
On descent; SADDE 6 arrival; just prior to SYMON. Prior to descent; we had briefed the ILS 24R approach; with a possibility 25L; and completed the Approach/Descent checklist. Just before SYMON; the relief officer mentions that the 24R LOC is out of service and the approach is actually the RNV-Y 24R into LAX. It was printed out on the ATIS; but we all missed that one. The Captain states that he will reprogram the FMC; so I continue to fly the aircraft while he and the relief officer get the correct approach in the box. At one point I hear the relief officer say 'Don't reselect the arrival' which I took to mean not to reselect the STAR. I'm not sure if he did or didn't; but something was executed without my confirmation. The autopilot was in LNAV/VNAV and the flight path was on the magenta line. Between monitoring the aircraft and keeping an eye on what was happening to the FMC I noticed that the plane was not actually on the magenta line but headed straight for SYMON. I selected HDG and attempted to regain the course to BAYST. It was evident to us and to SoCal Approach that we were going to bypass BAYST instead of going over it; and SOCAL cleared us direct SMO; clearly not impressed with our navigation skills. I'm not sure what was programmed into the FMC; or why the plane didn't stay on the magenta line when LNAV was on the FMA. I was not asked 'Does this look good to you?' before anything was executed; probably because there was a time constraint to get the reprogramming done. As pilot flying; I felt my duty was to fly the aircraft while the Captain and relief officer attended to other duties. There was clearly a break down in communications within the crew. There were no personal conflicts between us on the flight deck; and I felt we all got along. Fatigue was definitely a factor. Also; we have all been into LAX a bunch of times and it's always the same arrivals and approaches. Except for this one. Attention to detail is difficult when fatigued; but not impossible. But recovery from an error while fatigued can be confusing and over wrought. So; get it right the first time; define roles; correct errors using well established SOP; and don't get wrapped around the axle if something goes wrong.
Widebody international flight crew reported a track deviation when they got an unexpected clearance on arrival into LAX and had some difficulty programming the FMC correctly. Reporter cited fatigue as a factor.