It would be easy to make rigid landing gears, but I wanted to venture into the challenge of making retractable gears still strong enough to carry the weight of the model. I was lucky to find
this YouTube video showing the landing gear of the real plane in action, offering me a model to imitate here.
So here it goes,
watch this video demonstrating the landing gear function!
Here's a photo and
another one showing how the landing gear system is made. The key is
this piece which allows one-way-only gear function, preventing the landing gears collapsing by themselves.
As for the another function shown in the pic above, the top of the fuselage is easily detached to access the interior.
Click this to see the said image in higher resolution.
To note, even though the model is roughly in minifig scale (or even slightly bigger), still there isn't so much room inside as in the real plane (for instance, only one figure can fit in the cockpit). This is naturally due to three facts: Lego pieces are relatively thick; minifigs have sort of fatty body structure; and a Lego model requires all kinds of supporting structures taking space. These realities have unavoidable effects when building with Lego. Also the pilot must sit further back than in the real thing, because the nose of the model is so filled with internal builds keeping it all together.
Regardless, this model has a nice interior including seats for passengers, and in the back we have room for cargo!
Pondering on a possible price of a set like this... This model is made of around 2,500 pieces! It'd likely be a licenced product. Perhaps a good set for comparison would be
10177 Boeing 787 Dreamliner, another detailed and licenced airplane model from LEGO. That one was $80 with 1197 pieces making price-per-part ratio $0.067. If this came out with a similar PpP, still observing the general LEGO fact that bigger the set is lower the PpP goes, then, licence included, this might cost somewhat near $160.
Which, in my opinion, would not be much for a LEGO set this special, this unique, and this BIG: