Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Human-Machine Interface; Fatigue; Confusion; Communication Breakdown; Training / Qualification
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach; Inflight Event / Encounter Weather / Turbulence
Flight Crew Executed Go Around / Missed Approach; Flight Crew Overcame Equipment Problem
Human Factors; Company Policy; Aircraft; Weather
After review of the details in the question and answer part of this report; it became clear the importance of 777 requirements that the vertical PATH be protected by the pilot flying. For example; had I; as Captain; exercised my defined privilege to set the MCP; I would have set approach minimums as I ordered given authority to delegate. Apparently the First Officer; fatigued as well due to scheduling--made evident by missed radio calls--believed that the use of an ILS as briefed prohibited the use of LNAV/VNAV to place the aircraft both laterally and vertically on the ILS. At least two times an intermediate altitude was set from step down restrictions on the approach plate. Had the '[approach] minimums' been set in the MCP until the OM; the aircraft would have complied with vertical PATH. However; it leveled twice at ALT hold because of [selected charted crossing altitude] MCP settings.  As a result I had to intervene with degraded autopilot modes; i.e. vertical speed and FLCH; to get the aircraft going back to PATH. Due to my slower crosscheck; a strong pattern altitude tailwind; haze; and calling 'runway in sight'; the aircraft flew too high for a [stabilized thrust] approach. At go-around; the aircraft was configured at idle; descending above slope in clear skies with haze. The crew [agreed] that the approach should be aborted. I executed a go-around. Due to radio communication difficulties during the initial approach the First Officer requested approach clearance clarification and another ILS was assigned on base leg. This FMC update was accurate and an at or above altitude was changed to a hard crossing altitude so that VNAV PATH would be protected. This was important due to maritime haze that made it difficult to assess height above the ground. The 777 immediately show[ed] PATH and continued a normal descent until hitting the MCP altitude previously noted. Please note that PATH respects approach requirements which clear terrain and the touchdown point. V/S and FLCH do not and simply move the aircraft vertically without regard to restrictions. I believe PATH is safer for this reason and has proven safe in both VMC and IMC conditions. Provide added emphasis that the pilot flying needs [to] set MCP even during approaches; with confirmation from pilot monitoring so that the LNAV/VNAV system does not compromise the vertical PATH. Once this occurs; regaining the PATH; especially with a tailwind is difficult. Alternately; use LNAV/VNAV approaches so there is comfort level for pilots who are ILS only flyers. ILS guys do not like to mix in LNAV/VNAV procedures in my experience on the 777. The Runway 15 ILS at SBGL is quite abrupt when it is intercepted; the glideslope in particular; due to other aircraft ahead on final in VMC conditions. The VNAV is much smoother.
An apparent breakdown in Mode Control Panel SOP; fatigue; and poorly coordinated efforts by the flight crew of a B777 resulted in an unstabilized approach and subsequent go-around.  Contributing factors were conflicting comfort levels with LNAV/VNAV conducted descent to ILS intercept and the failure of the Captain (pilot flying) to assume control of the MCP panel when conflicts arose between his autoflight configuration preferences and the First Officer's reluctance to abide by his planned utilization of LNAV/VNAV to join the approach.