We have been flying an X8 flying wing for the best part of a year and it behaves really well in manual, stabilised or RTL modes.
However we have noticed that it is super stable in fly by wire mode B, but the aircraft slowly gains altitude even with the elevator stick held fully forward (down). It also turns perfectly to the left, but really doesn't like turning to the right. I.e. a left turn will roll the aircraft to 60 degrees and turn very rapidly, but the right turn barely rolls 10 degrees and turns very slowly, massive bomber command turns.
Put it back into stabilised or RTL and it behaves and rolls perfectly both ways, left or right.
We changed the maximum bank angle to 60 degrees in case anyone was wondering!
So, does anyone know why it would be having this issue in only Fly by Wire B mode?
Replies
It’s very goofy but the default in FBW B is down elevator makes it climb and up elevator makes it descend. I never could understand the logic behind having FBW A and FBW B having different elevator polarity. I don’t remember the exact parameter name but there is a parameter to change it back to normal (up elevator goes up).
FBW B is a strange mode. I use FBW A most of the time when I am not in auto or loiter.
They should change the default – it would prevent some crashes.
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Hey Quentin,
If you could post your parameter file it will help people perhaps give you more than best guesses. Also if you can post a tlog from your flight with FBW B mode that could be useful too.
Regards,
Nathaniel ~KD2DEY