Originally Posted by
Chris Scott
I have to disagree. Unless the OP is excluding centre-section fuel tanks from the discussion, or limiting it to business jet-sized aircraft, his/her question is perplexing. From personal experience the vast majority of medium-to-large airliners have centre tanks.
Well yes, that's why I
didn't say "there isn't
any room", just not much space.
The other side of the coin is that many (most?) current narrow-body airliners have ACT provision, but only at the expense of baggage/cargo capacity.