Even if it’s named at “helicopter”, the Lego Technic 42057 is a autogyro/gyroplane with a big main rotor and a vertical rotor on the rear.
There is also a 2-cylinder engine in the back. The main color is white, with red stripes printed on stickers and it contains 199 pieces. Although I prefer cars as entry models to get yourself familiar with Lego Technic this set is a nice one as well for beginners. You can 'steer' your helicopter with the small red lever on the side to orientate the tail rudder.
The B-model looks like a single person flying car. A nice fantasy design which is fun building as well. The fun is that in this relative small set 2 ways of engine configuration are shown. In the A-model a line setup of 2 cylinders, in the B-model a boxer setup.
Because this set contains 3 wheels I expect with some imagination you can design a trike.
I really like it that this engines are used in the smaller sets as well like the 8256 - Super Kart, 8818 - Baja Blaster / Desert Racer, 42002 - Hovercraft, 42045 - Hydroplane Racer, 8225 - Road Rally V, 8296 - Dune Buggy, 9392 - Quad Bike, 8815 - Speedway Bandit to name a few.
The smallest one is the 1260 - Car with just 26 pieces