Other than the planes, I do find it unfortunate that the Friends set focuses on shopping and food like so many Friends sets, and I also think it is unfortunate that the City terminal only has the basics of the airport structure in the control tower and service truck. Having a control tower for the Friends set would have been great. Having a gift shop/cafe for the City terminal would have been a worthwhile addition and not something we have seen in many City sets. 

Compared to other major European hub airports, like Charles de Gaulle or Heathrow, CPH has a similar number of connections, but is much smaller in both actual size and passenger volumes, and can provide a calmer, more pleasant experience. Its location in the south of Scandinavia makes reaching most European destinations reasonable, and flying to destinations in the Baltic region and in Eastern Europe generally only takes half the time as from major hub airports in Western Europe.

Attention then shifts to construction of the three aircraft. When I first spied this set I assumed that the two red jets were the same, but closer examination reveals a number of differences. First up is a red jet with a canard wing configuration as seen in the Saab Viggen amongst others. The lower fuselage is fashioned from a number of double and triple inverted 45 degree slopes with a pair of 1 x 14 Technic bricks running through the centre; there’s no obvious reason for Technic bricks to be used in this situation – standard 1 x 14 bricks would have done the job just as well - so I assume that LEGO just happened to have a bunch of them lying around…. A printed black 1 x 2 tile in the cockpit represents the instrument panel, while a substantial air intake is attached on either side of the fuselage at a 90 degree angle by way of brackets.
The final two minifigures are the Biplane Pilot and the intrepid Wing Walker. Both of these minifigures share the same white torso which is printed with a flight suit design overlaid with dark red and bright light orange flames plus a logo over the left breast. The torso design is superb and it can at present only be found in this set. Both minifigures are provided with a reddish brown aviator cap and dark bluish grey goggles, and the pilot (below left) also gets an alternative to this headgear in the form of medium dark flesh mid-length hair which has only ever appeared in five sets in this colour.
There are several robotics competitions which use the Lego robotics sets. The earliest is Botball, a national U.S. middle- and high-school competition stemming from the MIT 6.270 Lego robotics tournament. Other Lego robotics competitions include Junior FIRST LEGO League (Jr.FLL) for students ages 6–9 and FIRST Lego League (FLL) for students ages 9–16 (age 9–14 in the United States, Canada, and Mexico). Jr.FLL and FLL offer real-world engineering challenges to participants. FLL uses Lego-based robots to complete tasks. Jr.FLL participants build models out of Lego elements. In its 2010 season, there were 16,070 FLL teams in over 55 countries. In its 2010 season, there were 2,147 Jr.FLL teams with 12,882 total student participants in the United States and Canada. The international RoboCup Junior football competition involves extensive use of Lego Mindstorms equipment which is often pushed to its extreme limits.[53]
Play out real-life scenarios in LEGO DUPLO Town: a recognizable world with modern DUPLO figures. Help your little pilot get ready for take-off at the LEGO DUPLO Airport! It's easy for preschoolers to build the boarding gate, luggage slide and revolving air traffic control tower. Makes an ideal gift for preschool children. Contains 29 pieces. Airport measures over 8 (22cm) high, 5 (14cm) wide and 4 (11cm) deep. Plane measures over 3 (9cm) high, 7 (18cm) long and 6 (17cm) wide.

@josekalel: I think the size of the terminal is kept in check for price reasons more than anything. This is a $100 set, and while bigger and pricier City sets exist, they tend to be few in number. What's more, the disadvantage to having a plane wide enough to seat two rows of passengers is that it inevitably takes up a big portion of the budget even for a larger set like this one. If the set were just the airport with no plane, then the terminal could probably be around twice this size at the very least… but then the set would not offer such a complete play experience.
Every good airport needs a hangar for the planes, and this is no exception. The satisfactory hangar included here does come across as rather basic, and while it doesn’t detract from the overall package, it isn’t going to swing your decision over whether to purchase this (and truthfully, I think you would have already made that decision before you come to the hangar). The design itself is simple, with the build unlikely to take you more than 10 minutes. That being said, it is a well-built piece and doesn’t feel flimsy, which was the impression I had when I first saw a picture of it. The criss-cross pieces towards the base give it a firm foundation, and there are plenty of long pieces which add further stability to it. Plane-wise, it is best suited for the old-fashioned vehicle, with the orange colouring in the design going well with the plane. Only a couple of stickers in use here, with just the AIRSHOW HANGAR words needing to be added.
Agent 13 has a pretty plain appearance, with caramel-coloured wavy hair, and a black, spy-like top. Her torso has some nice details, with sharp, angular lines that all combine to form a rough outline of an upside down star. She has plain sand blue pants and rocks a sub-machine gun accessory. I like regular LEGO firearms, so it’s very nice to get one in this set as they’re fairly uncommon.

^ Jump up to: a b Alexander, Ruth (3 December 2012). "How tall can a Lego tower get?". BBC News. Archived from the original on 4 December 2012. Retrieved 4 December 2012. The average maximum force the bricks can stand is 4,240N. That's equivalent to a mass of 432 kg (950lbs). If you divide that by the mass of a single brick, which is 1.152g, then you get the grand total of bricks a single piece of Lego could support: 375,000. So, 375,000 bricks towering 3.5 kilometers (2.17 miles) high is what it would take to break a Lego brick.

The remainder of the build is the control tower and terminal building. First there is a metal detector screener leading to the waiting/secure area of the airport, which seems taller than it needs to be for the minifigures. I think the same effect could have been made with half the height, except that would not allow for an impressive height for the overall tower. However it does seem to be similar to many modern airports with the high ceilings. This area also seems to be someplace to check luggage as evidenced by the rather nifty conveyor belt that comes in a full part. The moving parts of the set include a revolving door (a very tall one, for the first floor) that leads from the secure area of the airport out to the tarmac, and of course the conveyor belt.