Not as fat? Well, they do have the same fuselage cross section, and yes, the MD-11 is in fact longer than the DC-10. The winglets are very visible, and to anyone who has X-Ray vision a la superman, can peek inside the flight deck to see the 3rd crew member. For those of us that have normal vision, that’s a little impossible. So no, I won’t be looking for the 3rd crew member any time soon in order to distinguish between the 2.