Correct - the hanger can only accommodate the biplane. That having been said, in order to accommodate the other aircraft too the hangar would have to be huge, with an enormous footprint, and a substantially increased parts count. As a result, I'd estimate a price up to double the current RRP which I suspect few of the target market would pay. LEGO therefore got the size of the hanger right IMHO.
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.
Here’s a look at the Iron Man and War Machine minifigures. Tony Stark is rocking his Mark 46 Armour which should delight LEGO Iron Man collectors as it’s another cool variant. If you ask me, I can’t quite tell most of the suits apart, but I do appreciate that LEGO give us a fresh new Iron Man minifig with each movie-themed set. Both Iron Man and War Machine are exclusive to this set.