Pixhawk twitchy YAW and not disarm on crash

Hi everyone, hoping someone can help me with my pixhawk problems.
I just rebuilt my old quad on a new alien 560 folding frame, after much playing about getting everything CG balanced I took her out for her maiden flight today. (was a bit scary)

1st attempt:- In loiter with 12 SATS Pitched backward, hit the ground flipped over and disarmed itself.

2nd attempt:- Re-calibrated compass’s In loiter 12 Sats, I took off quicker this time getting a couple meters altitude, on takeoff again pitched backwards then settled. Hoving very jittery and yaw input from trans very twitchy, kept yawing to the left and drifting backward, all stick inputs very twitchy, after a couple minutes I landed, on landing it pitched backwards one of the rear props dug into the ground and stopped spinning the other 3 props keep spinning very fast with throttle stick at 0, nothing i did would disarm the pixhawk. I had to unplug the battery to get it to stop, which is quite scary when you got 3 of the 4 15 inch carbon fiber props spinning flat out.

PID’s are at default settings…

Any help would be appreciated.

Flight Fottage https://youtu.be/ZdYoIcTrd8A

1 Like

i had a similar experience but my copter settled down after a few second and also on the same flight after going to about 400 ft alt it was a little windy so i lifted my retract to reduce sail area. after a few minutes of hovering in place i went to bring it a little closer and found that my pitch and roll controls switched my pitch now controlled my roll and roll controlled my pitch. i finally got it closer so i dropped the gear to land and found that the controls had switch back to normal it was late last night so im going back out to day to see what its going to do

Ik this post is from 8 years ago but i am having the very exact same experience here in the same order. On the first flight it flipped over on i recalibrated everything and now my pitch controls don’t work and it carshed in to the wall breaking the prop and the only way to it was to unplug the battery. If you have solved your issue could you please tell me how i could fix my drone. Here are the specs.

DJI F450 frame
1045 prop
3s Lipo Battery
2213 935kv motors
flyskyfs-i6s transmitter
oneshot125 35 amp esc
pixhawk 2.4.8
Qgroundcontrol software.
thanks in Advance