United will change its boarding Thursday so that after elite-level customers, the rest of the coach cabin will board window-seat passengers first, then middle seats, and aisle seats last.

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If the regulating valves fail or if the cabin structure is breached (by a failure of a door or window for example) then the pressure in the cabin would suddenly drop to match the outside air pressure.

BBC: NEWS | Europe | Dangers of aircraft decompression

Open at least one window a small amount to prevent carbon dioxide from building up in the passenger cabin while you wait for help.

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It carries six passengers and two pilots, with nothing but identical window seats and transparent roof panels, since you will have the option of unbuckling and floating around the cabin during the zero-gravity portion of the flight.

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