B777-200
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Physiological - Other; Confusion
Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Illness / Injury; Inflight Event / Encounter Unstabilized Approach
General Physical Injury / Incapacitation
Human Factors
As we were descending onto a downwind at ZZZ airport I started to sweat a little bit and turned my vent on. Turning base to final the autopilot started crisscrossing centerline trying to establish. I took over manually and was having a hard time concentrating on flying the airplane. I felt like I was woken from a REM sleep. I had been awake for over 2 hours. I had a difficult time doing two things at once. I wasn't scanning; just staring. My FO (First Officer) and [Relief Pilot] were offering guidance but sounded like distant voices. Around 700 ft. AGL I managed to force myself to concentrate and made a pretty sweet landing and turnoff. Upon setting brakes after a short 4 minute taxi I ran back to the bathroom and threw up a significant volume. The nausea hit me immediately. I threw up several times in a bag in the crew van and also a few more times at the hotel. I don't know what happened. I think I was developing physical symptoms of illness in the terminal area. Not the nausea which hit after parking the brakes. Maybe my blood pressure dropped or something but I was mentally out of it mostly on the approach. I didn't take any medicines or supplements but I did eat 4 hours before I got sick. It was clear and a million on the approach and though I only have been in the 777 [for several months] I have flown into ZZZ a couple dozen times. I felt OK; about 80%; the following morning and just slept all day. By pickup that evening I was fine. Though my chest was very sore from dry heaving. On the approach I think I exceeded flaps 30 max speed of 170 KIAS as well. The IAS was plus or minus 15-20 knots as it was very gusty from 4000 ft. to touchdown. I also had a glide slope warning at about 1500 ft. AGL I was told but I don't remember it. I think I experienced an initial insidious physiological sensory degradation from food poisoning. As I descended onto downwind. That's all it could be. I was so sick for the rest of the evening and the vomiting started maybe 8 minutes after the awful approach I conducted. I just do not fly an airplane that bad.
B777 Captain reported feeling partially incapacitated during the final phase of flight; possibly due to food poisoning.