Date: 201501
Aircraft: B777 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Anomaly: No Specific Anomaly Occurred All Types
Detector: Person Flight Attendant; Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Company Policy; Human Factors
Primary problem: Company Policy

Narrative: Enroute to VHHH potable water supply was exhausted 3 hours prior to destination. This was approximately 12 hours into the flight. Approximately 90 minutes from destination all remaining bottled water was also gone. Approximately 275 people on board this aircraft had NO water; after flying for 12 hours+ in the well-known extremely low humidity conditions of a non-humidified aircraft. Upon realization that the potable water was empty; the captain directed the crew to ensure they had enough bottled water to provide for our basic physiological needs. Communications were established long before; when it was apparent that once again this flight would be severely short on water. Discussions ensued regarding the safest and best course of action for the passengers and crewmembers; including our suggestion to divert to Beijing to replenish the water supply. We passed essentially directly over Beijing shortly after the water ran empty. We were told that a diversion to Seoul South Korea would be much better for passenger considerations; however the flight time to get there would have been approximately the same as going to VHHH and therefore offer no relief to the situation. One would be naive to think operations wasn't well aware of this and therefore I view it as merely a non-option; lip service to allow them to say they offered us an option. Upon discussions among us crewmembers; we agreed that while margins of safety were indeed compromised; and passenger physiological needs were severely compromised; under these circumstances it was not unsafe to continue to Hong Kong; and therefore did so. It is of significant importance to note that extreme pressure to continue was applied by the operations manager and Duty Manager; their only verbal consideration being duty time issues for the crew (and the inability to continue if we diverted) and passenger issues diverting into mainland China. According to the operations management team; water (for 275+ people; on a 15 hour flight in less than 10% humidity) is a 'passenger convenience!'  Their words; not mine. 'They definitely did not want us diverting for a passenger convenience item.' This is very disturbing. Our condition: No water for 275+ people for 3 hours for basic consumption and physiological needs; after 12 hours of flight. A compromised toilet system. No water to wash hands for basic sanitary needs. Discovery that; as a result of the company's severely flawed directive to eliminate any 'excess' weight from the aircraft; they have also removed bottled 'hand wash' as well; leaving nothing but a limited supply of towelettes for sanitary washing needs. No supplemental water to fight a potential cabin fire; or immerse a potential burning laptop; tablet; or cell phone battery per safety procedures. It is also important to note that procedures were previously in place to load an appropriate -reduced- quantity of potable water based on flight time and passenger load; as opposed to the ill-advised decision to cap off and disable one of three potable water tanks. This decision removed no weight from the aircraft but removed all discretionary ability to load an adequate amount of water when needed. Furthermore; in response to a previous report of the same nature; I was told that company engineers have determined that 218 gallons of water is sufficient vs the 327 originally designed for this aircraft. I would suggest that based on my encounters; and numerous verbal reports I have received from others flying the 777 and running out of water; that these 'engineers' are either using flawed calculations; or using flawed assumptions when performing these calculations; or both. Either way; it appears Boeing engineers might be a little more adept at their job; as we are regularly running out of water on our long flights. Most importantly; this company's decision to remove 1/3 of our potable water is compromising the safety and basic physiological needs of passengers and crew.




Synopsis: B777 First Officer; on a 15 hour flight to VHHH; reports running out of potable water again due to the company's policy of only filling two of the potable water tanks to save weight.