B767 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Total 5300; Flight Crew Type 3219
Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Illness / Injury; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Diverted; Flight Crew Landed As Precaution; Flight Crew Landed in Emergency Condition; Flight Crew Requested ATC Assistance / Clarification; General Maintenance Action; General Physical Injury / Incapacitation
Aircraft
Cabin crew got lightheaded and dizzy; followed by pax same; spread from aft to whole cabin. No odor; fume detected. Multiple cabin crew and pax had symptoms. Decision to make a cautionary divert.Established at FL320; got call from aft cabin Flight Attendant that two of them were feeling lightheaded and dizzy; we agreed to cool down cabin and told them to keep us informed; Less than five minutes later we got another call that some passengers also were feeling lightheaded and dizzy; We called [maintenance] and Dispatch on conference call and all agreed that aircraft was nominal and we'd continue to monitor while thinking of a possible divert; less than fifteen minutes since initial call we also got a call from the purser that the entire cabin crew were also getting lightheaded and feeling dizzy.The decision to divert [was] made and we called the IRO (International Relief Officer) back to the cockpit from his break; ATC gave us expedited handling to ZZZZ where an overweight landing was made following the  'Cabin Air Quality procedure' and 'overweight Landing' procedure as well as normal approach and landing. F/O (First Officer) was directed to don oxygen mask as the flying pilot as part of normal ZZZZ procedure.Landed rolled to end of RWY using reverse and min braking to minimize heating of brakes. After exterior inspection by Fire and Rescue we taxied unassisted to [the stand] where we were met by EMT who took care of affected crew members and passengers; aircraft handed over to maintenance and flight crew went to the hotel.
I was PF (Pilot Flying) on this leg. Approximately two hours into the flight at FL320; we received a call from the aft flight attendants about one of the flight attendants feeling dizzy and nauseous. They asked us to cool the cabin down in the aft section; which we did. Shortly after that; we received another call from the aft cabin that the flight attendants were not getting 'enough airflow' in the aft cabin. We further cooled the aft cabin to approximately 71 deg and explained we could not change the air flow rate. We asked them to ensure the gasper vents were open. Approximately five minutes later; we received another call from the aft cabin FAs stating that there were several passengers in the aft cabin who were also experiencing similar dizzy and nauseous symptoms. At this point; [the Captain] performed a sat phone patch to dispatch and [maintenance] to discuss the situation and evaluate potential divert options. We decided if we made the decision to divert; that ZZZZ would be our best option for the following reasons: 1. Longest runway since we would be 38;000 pounds above max landing weight. 2. Extensive crash rescue firefighter support in the event of hot brakes upon landing. 3. Adequate healthcare support and facilities to accommodate sick passengers. 4. Largest chance of re-booking passengers to their destination. 5. VMC weather conditions. While [the Captain] was speaking with [maintenance] and dispatch; we received another call from the forward FAs stating they were experiencing similar symptoms to the aft passengers and FAs. At this point; we decided in concurrence with [maintenance] to divert to ZZZZ and alerted air-traffic control of our intentions. We asked the forward flight attendant to wake up [the First Officer] and have him return to the flight deck in preparation for diverting to ZZZZ. At no time did we experience or detect smoke or fumes; nor did we experience any of the symptoms of the passengers and flight attendants. The aircraft pressurization system and cabin altitude were normal. Prior to [the First Officer] arriving on the flight deck; we consulted the smoke; fire or fumes QRH; but concluded it did not match what we were experiencing. We also did not feel a MedLink patch was appropriate since we had multiple people who were sick with similar symptoms that seemed to be aircraft bleed system related and not a medical condition.Once [the IRO] arrived on the flight deck; [the Captain] briefed on the situation and we divided duties where I would fly and talk with ATC; while [the Captain] communicated with the company; station; FAs and passengers. Out of an abundance of caution; I put my oxygen mask on for the remainder of the flight. [The IRO] worked on the QRH checklist for overweight landing and fuel dumping. Dumping fuel would only eliminate 8;000 lbs of fuel and we would still be 30;000 overweight after dumping; so we decided against the procedure since we were descending over a populated area and thought it was more important to focus on properly flying the arrival and set up for approach/landing.After the arrival and approach were loaded into the FMC and [the Captain] and First Officer finished their tasks; we briefed the arrival; approach and overweight landing into ZZZZ. I briefed a flaps 25 landing since it would only be 1 knot faster ref than flaps 30; but would provide a much higher speed margin between target and max flap 25 speed. However; [the IRO] noticed the overweight landing QRH called for flaps 30; even though our target speed would be within 7 knots of max flaps 30 speed. We complied with the QRH and set flaps 30 for landing with auto brakes 1; planned to use max reverse until 80 kts and full runway length. A normal touchdown and long rollout was performed. We exited at the end of the runway where ARFF (Aircraft Rescue and Fire Fighting) contact was made and a visual inspection of the aircraft and brakes were performed by ARFF. Our highest brake temps indicated 2 onthe BTMS (Brake Temperature Monitoring System). After an all clear was given by ARFF; we taxied to the gate. [The Captain] fielded questions from pax; FAs; station ops personnel; maintenance and ARFF. The pax and FAs who had symptoms inflight were evaluated and released by the EMT personnel. The flight attendants told us they were feeling better and their condition was improving. Upon reflection; it's possible we may have encountered an area of high Ozone concentration which could have led to some of the symptoms experienced by the pax and FAs and would explain the rapid recovery upon landing in ZZZZ. The trop was at 30;400 ft based on our [flight plan] and we were at FL320 for nearly 2hrs. While no ozone hazard area was depicted on our route map; the levels may have been sufficient to affect a portion of our pax and FAs. We did not think about running the Ozone Encounter QRH at the time; since we were not depicted to fly near any Ozone threat areas.
B767 flight crew reported that the quality of air in the cabin caused the cabin crew and some passengers to become light headed and ill. The ozone converter was reportedly a contributing factor in the event.