Originally Posted by
pattern_is_full
That, of course, leaves aside how much more airlines would have to pay Boeing, per aircraft, to completely revise the jigs and tooling to accomodate differently-sized airframe parts. Including, for example, control runs, floor panels, or a new ceiling (unless you'd accept a 20cm gap down the middle overhead between the carry-on bins
).
Yes - the best time to increase the cabin diameter of an aircraft is while it's still on the drawing board, cf A350 -> A350XWB.
