Originally Posted by
procede
With a narrowbody, the fuselage would be so long, it would mean a heavy structure to counteract the bending and also very high and/or complex main gear to not have a tail strike on takeoff and landing and still get to an appropriate angle of attack. Going to 2-3-2, like the 767, you are adding a aisle for a single extra chair per row. Aisles do no generate revenue, but do add volume (drag) and weight, making the aircraft increasing the cost per seat.
The DC8-63 had the same length or a bit more.. It had an extended fuselage with a length of 57.1 meters, same as of the -61. It has a height of 13.1 meters and a fuselage diameter of 3.74 meters. It is 11.5 meter longer than the conventional DC-8 that was developed in the late 1950s. Some tail strikes and of course there was bending, you could watch from the tail the forward compartments moving from side to side.