Bag 4 finishes the fuselage and all that is left are the engines and tail section.  You'll notice that this aircraft has a bathroom on board as well as some storage for a non-existent flight attendant.  I think this is the first time that LEGO has put some additional details into aircraft besides just seats.  Also there is only one pilot for a 2 seat cockpit in the set.  
This is a good set if you want an airport. The set includes a big plain and a terminal. The terminal has a control tower, check-in, luggage handler, fuel tank, ... I expanded my terminal and built it on a 32x32 baseplate and used the 2 grey 16x16 plates for the roof. The backside is not completely closed. Otherwise is the luggage belt is not accessible with my hand. I added 2 extra seats in the plane. Normally you have 6 seats in the plane, but I raised it to 8. I wanted more than 8 but that is almost not possible. The plane is brought with a big brick which includes the middle of the plane and the 2 wings and that one limits the possibilities. The toilet in the plane is still on the backside.
Since around 2000, the Lego Group has been promoting "Lego Serious Play", a form of business consultancy fostering creative thinking, in which team members build metaphors of their organizational identities and experiences using Lego bricks. Participants work through imaginary scenarios using visual three-dimensional Lego constructions, imaginatively exploring possibilities in a serious form of play.[73]