The answer is simple mathematics - check out the cabin width of the mentioned planes: B777 582cm A350 561cm B787 550cm A330 528cm
18in seat is 45.7 cm
i.e. aisles in standard configurations are: A350 75.85 cm A330 81.2 cm (actually the seats are wider than 18" and the aisle remains within prescribed width.)
To access B787 is not so easy since there are two "regular" seating schemes 3-3-3 aisles MUST be at least 75,5 cm i.e. there is simply no space for 18" seats - cca 17" is left no more. In "ANA" configuration 2-4-2 there is of course space more then enough.
If we consider A350 in similar manner - 3-4-3 only a bit over 16" is left for a seat - less than 3-3-3 in A330 ! A330 in 3-3-3 is also nothing to happily travel in - 16,5" left for one seat.
Come back to B777 - seating 3-3-3 is fine there full 18" left for one seat. How ever 3-4-3 (promoted lately by EK and others) leaves for a seat 16,9" and it is considerable difference - tested once while flying with their 777 in this configuration and then changing to A380 with 18" and believe me it is a DIFFERENCE.
Usually A320/B737 seats are more comfortable than this.
I just read that 3-4-3 on A350 will be 16.9", according to Airbus. They work on the armrests... I am curious to see how they do that.
Like this -
There have been a couple of suggestions for the armrests for the seats by the window, one was a narrow armrest with no aluminium structure inside and the best I heard of was to try and recess a small armrest into the interior wall cladding therefore saving the space of two armrests per seating row, may be 4 inches a row ?
16.9" - well I do not understand that - they might measure the seats in the widest internal width of the fuselage not on the floor..... still it is peculiar. Simply the numbers does not fit. The only alternative would be narrower aisle and maybe than special food drink containers, and some exception for narrower aisle ? What suggest stelthmanbob makes sense but who would want to have such an armrest ? What with the legs of the poor windows passenger ?
Anyway it is interesting how the "scissors" between the majority of people the Y "commoners" and the C/F "elite" gets wider and wider. I do believe that year by year the difference increases.
Some personal advice not only good for the A350: If airlines want to desperatly squeeze in even more passengers per plane we clearly need fully optimized seats in economy:
NEVER put any IFE-box under any seat anymore. (Still happening) NEVER put any strut or other limiting thing inside the space for passenger feet. NEVER put inflight magazine-, vomit-envelope-storage pouch where your knees just have to be. Move those things upward to the top of the neckrest. Curve out the kneeroom area as much as possible. No more tray-struts or seat frames there. No more sharp edges at hidden places down there please. (I have serious scratches in some of my leather shoes from putting my long legs too far under aircraft seats)
Plus: design armrests to become just seat dividers not true armrests to lay down an ellbow on anymore. Have everybody put his arms and hands forward on his own lap instead. Limit or ged rid of entirely of any seat recline. If you have to sit so tight reclining will just cause trouble. Any recline that limits knee room even more has no more sense. Provide drinks and food install a free WLAN or IFE monitors to keep people busy and distracted from their misery.
Last Edit: Jan 11, 2016 10:12:08 GMT 1 by airboche