Airbus A350-1000 has been certified for maximum passenger capacity to 480 seats by European Union Aviation Safety Agency.
The current A350-1000 was certified to accomodate up to 440 seats with four 4 pairs of Type A Doors which allow for 440 passengers (110 pax per pair of Type A Door).
The new modified version of Type A-plus exit doors with a dual-lane evacuation slide, which allows 120 passengers per pair to accomodate 480 pax in total.
Aviation Regulators have defined the Exit Limits based on maximum number of passenger seats permitted for each exit of a specific type installed on each side of the fuselage., such as Type 1, Type 11, Type 111, Type 1V, Type A, Type B and Type C each defining the exit limit.
Type A. This type is a floor-level exit with a rectangular opening of not less than 42 inches wide by 72 inches high, with corner radii not greater than seven inches.
With the increased capacity Airbus will be able to directly compete with Boeing 777x, which is scheduled to make its first flight in 2020 after delays due to issues with GE9X engines and failed load test.