Originally Posted by
outofwhack
[I meant attack !]
Do any engineering types amongst us know how many degrees of pitch the blades of a helicopter typcially have when the collective is bottomed.
Just a rough answer is fine. I guess its still 2 or 3 degrees positive but would like a little confirmation.
I am returning to flying model helicopters as well as full size and would like to master the art of autorotations with models [to save me a few quid if engine stops].
Many in the model fraternity seem convinced you have to have actual negative pitch but every vector diagram I have studied for fullsize shows some amount of positive pitch in the simplified diagrams [that neglect washout etc].
For interest and from my own observations it appears model helicopters use a range of 5 to 9 degrees for hover and max power.
OOW
Not engineer, but fairly sure you're right about very low positive. Model heli's do however often have -ve pitch for acrobatics - have you not seen them hovering upside down?
cheers
ian