V3.5 rc1 uncontrolled flight

After dozens of perfectly stable flights my 960 hex decided to have it’s way with me. I went out to the flying field to test telemetry range with TX1 (not the first time with TX1). Just after take off it twitched and started heading off on it’s own, after a panicked attempt to regain control I finally managed to hard land with minimum damage. I am not well versed at log reading so if someone would be kind enough to look it over I would be forever grateful. I don’t think it is firmware related but I have been over the craft and can’t find any problems. It flew last weekend several times and no changes have been made since.

RB97.BIN (785.7 KB)

When you switched from Land to Stabilize the position of the copter deviated. The GPS shows you never leaving the park area where the calculated position shows it went 500 meters across the road by the trees.

See several EKF issues. beyond my expertise.


Thanks for looking Mike, I really need to learn how to sort through the logs. Something about teaching old dogs new tricks😎 I put it on the bench and went over all the wiring and hardware then flew a couple of meters off the ground in my yard. It seemed OK except for a couple of slight twitches at first that showed up on the log as ground mag anomalies. There are a lot of electrons moving around in the belly of this thing and I have taken precautions in the build. I’ll look closer and try a flight back out at the field as weather permits. Thanks again for taking the time to help me out.


the mag data in your log looks like you have the wrong compass orientation. Also the Auto Analysis tool complains about high compass offsets.
You should check the orientation of your external compass.


Thanks for the look Hubertus, this set up has been working perfectly for over a year and I haven’t changed anything except for the addition of the TX1 and I have done a dozen or more flights after I installed it. I may change out the GPS/compass and try again when I get the weather to cooperate.


Just an update for @iseries and @Hubertus_Paetow, and anyone else interested. I exchanged my pixhawk for a known good unit I had on the shelf, loaded the parameter files in and everything is back to normal. This hex has been flying perfectly for the last year and I felt it had to be a hardware issue. Either that or our current administration was jamming personal drone flights at a tiny airfield in remote western Washington.

Thanks again for the help