One question .. I discovered that when I lower the blue levers .. The propeller blades change shape ... What is that function for? Is it for a safer landing? Find out what makes the revolutions per minute go down ... They might respond please
The blue lever changes the target rotation speed of the propeller. The Baron has a constant speed propeller, which means the engine and propeller rotate at a constant speed regardless of how fast you fly and how much power you apply. When you add more power the blade pitch is automatically increased to grab more air and thus increases the torque on the driveshaft but the rotation speed stays constant.
You can probably find millions of search results online for "constant speed propeller"