Before everything I wanted to do you the compliments for the product

Hi Filippo,I think you're asking about not being able to move the pitch angle of the propeller when the engine is off?If that's the case, it's explained in the manual for the B1900 that the propeller is controlled by oil pressure from the engine, and therefore when the engine is off, the prop angle cannot be changed, so they opted to always have it feathered when off.I hope that answers your question!

thanks...Filippo