Quad motor tail sitter quadplane pitch question

Hello there!

I have built a quad motor tail sitter and have completed a test flight with transition to and from level flight. Here’s a vid with more info about the flight in the description: Quad tail sitter first test flight - YouTube

I felt that it handled well for the most part but did suffer from a lack of pitch authority in level flight (FBWA) which I think caused an issue with the first transition attempt and although I had set the pitch limit to 70, it could barely pitch up past 10 degrees.

The differential yaw control is excellent and I’d like to implement the same for pitch.

I saw the parameter Q_OPTIONS and thought that setting bits 7 and 8 could help as according to the documentation, that should allow the copter controller in FBWA and thus give some differential pitch control. However when testing, setting the bits seemed to have no effect as the plane controller was in effect in MANUAL and FBWA modes.

What would be the best way to achieve differential pitch control in the plane flight modes?

Thanks in advance,


I think you have to be on plane 4.1 to get the q_assist forced option.
There is a active thread about quadplane tailsitter under “development team” where you will likely get answer to your questions.

Ah thanks, I’m still on 4.0. I’ll update and give it a try.