After updating to the 3.7 firmware we are seeing an abrupt nose up condition after the ARSPD_FBW_MIN is reached during the Q_TRANSITION_MS. Were were able to lessen the problem by reducing the Q_TRANSITION_MS from 5000 to 1000. We think that setting the Q_TRANSITION_MS to zero might eliminate the pitch up issue all together however things were working perfectly before updating to the 3.7 firmware.
Here are 2 screen shots from the quad motor RC outs. The first from the previous firmware and the second from the new firmware.
Here you can see the motors ramping up at the beginning of the Q_TRANSITION_MS.
Just noticed @garlandk had a crash which looks exactly the same thing. See his last post here: Quadplane Land Transition Issue
If he’s also running 3.7 then I’m worried about my next flight, as I’ve also just upgraded.
@tridge any thoughts on this?
I believe I was running 3.7 also… This happened in October if I remember correctly which was around the time 3.7 came out… I could be wrong, but I think this is true…
This really makes me worry as I have a brand new one ready to go. I just need to gain tune in hover and she is ready for a transition… Luckily my newest model is a lot lighter than the previous version. Fixed wing tuning is completed.
Consider performing your initial test using v3.6.0 firmware. This may provide more evidence if the issue is firmware related. I have had good success using v3.6.0 with the exception of RTL mode. Replacing RTL or Hybrid RTL modes with VTOL_LAND works well.