Need Help

[aviatorpalma]

Hello
Can someone please check question number 14569 of Principles of Flight and explain if possible why the correct awnser is the one that says incorrect incorrect? I think the answer is wrong because fine pitch it's actually a "little blade twist" or with low angle of attack. Would be nice to have your help. Thank you very much for your attention. Regards

[John H]

Hi aviatorpalma

Blade twist does not define if a propeller is coarse or fine pitch. A fine pitch propeller has a smaller blade angle than a coarse pitch propeller.

Hope this helps

John H

[aviatorpalma]

I agree with you John but I failed Principles of Flight exam by one question. I asked them to check the questions again and I saw I've failed this question, I spoke with the supervisor of INAC in Portugal and I told him that this question cannot be wrong because it's true the little blade twist actually it's not the same if it's fine or coarse pitch. I'm really in bad position, I have to prove them that I'm right to pass the exam .

[Dick W]

Blade twist, the change in angle as you go from root to tip, is not variable. The prop is made with a twist, and no matter how you attach it to the aircraft it will have the same twist. If you want a fixed pitch prop the both twist and pitch cannot be changed. With a VP prop you can change pitch from coarse to fine and back again, but while this is done the twist remains as it was when it left the factory

Dick

[aviatorpalma]

Thank you all for your help. Really appreciate it. I have a chance to prove them and that's what I'm going to do. All the best.