Flight with very poor control, minimal response to throttle

Hey fellas,

I have had an interesting situation. My pixhawk hex has been flying beautifully with the turnigy 9x radio with the 9xtreme board. I’ve upgraded to the Taranis x9D plus, to unlock 16 channels. I’d also updated to the 3.3.3 rc2 firmware, and redid the drone calibration (as I do for every firmware upgrade)

First test flight today, and things go crazy.

Great GPS lock, started up the thing in loiter. From the get go something was wrong. Stick inputs were very delayed and ‘dulled’ for a lack of a better descriptor, and it just flew off on its own in a straight direction. I changed to RTL to see if autonomous mode it could come back, but it still kept flying away. Changed to Stabilize to manually bring it back, which it kind of responded to.
Got low to ground, reduced throttle but it was descending too rapidly so I bumped up the throttle which it seemed to respond too. Flight was still erratic, so I shut throttle down to 0 as I wasn’t sure if it was going to go off again and couldn’t risk that. It landed, but then suddenly powered back up and flipped.

Looking at the hexa, none of the APC blades were damaged

Even with loiter and stabilise the drone was in an almost manual like mode i.e. not stable. It required a lot of effort to bring down

I have no idea what happened. This is bizarre, as the pixhawk has been flying beautifully before.

I’ve added a link to the log, and it would be great if someone could please shed light on what could have happened.

  • Log shows mid way through something happens with regards to vibration, which might explain why it did strange things. However, from the get go on launching the drone, the flying was already very strange, and erratic.

Today’s flight was to achieve 2 things:
1 - properly calibrate the voltage and current module as they have been off for a while and I had been using an external to the pixhawk telemetry to measure voltage and current
2 - to do a mag calibration with motors at max as I’ve just received my 3dr v2 radio

Radio has been calibrated, as has the compass/accel. 6 flight modes have been programmed using logical switches linked to physical switches, all modes switched well when testing via usb tethering to the pixhawk.

Frame: Tarot 690S
FC: Pixhawk
Power: power module with current sensing. For redundancy, there is a 5V ultra low noise UBEC together with diode in one of the aux ports
Motors: Turnigy Multistar 4822 390V
ESC: Afro 20A OPTO - updated to latest 2015 SimonK. Unable to induce any motor sync issues with rapid throttle oscillations during testing
Props: APC 12 x 4.5
Radio: Taranis X9D Plus

Bizarre throttle response, at minimum throttle twice, and but it didn’t translate to RCOUT throttle dropping

dropbox.com/s/zu3i8gj1l9lrm … l.jpg?dl=0