Strange aircraft behavior after landing crash

[Dustoff]

about a week ago I had a crash while landing with gps off . Broke four props and gimble mount . Repaired it the other day , performed a gimble calibration an accelerometer calibration . Was too not and windy to fly so I did not test the aircraft .

Well today it cooled off enough this evening and no wind so I venture out on the back forty to discharge my batteries so I could put a storage charge on them .

I performed a compass calibration and let the bird sit until it hag satellites and the started the motors and let it idle for a few mins . For a bit it seem okay but was a little slow in coming back down . I flew around for a short bit and checked that that I was in angle mode . Went up about 30 feet and the bird refused to come back down . It was also making a noise like it was fighting me to go lower . I then remember the trick about pushing the start stop button for a few seconds and was able to land safely using that trick . It took a while but it landed . Battery voltage at landing was at 15.8 .

To be safe I turned the aircraft off and moved back to the same spot I started and performed a compass calibration again . Took off with the same battery and it seemed to respond well. Went up a little and made a few landing and taking off again with out shutting the motors down.

Flew around a while longer to the 14.5 volt mark and the landed and changed battery. Made two more full flights on two batteries down to 14.5 volts with a couple of landings .

I did notice when on the first flight I had managed to land by pressing the start stop button that once on the ground I got a gps error.

Wonder if the aircraft defaulted to return to home for some reason and just hovered where it was. I was close to it but in angle mode and obstacle advoidance was off

 

[thoneter]

I've had this happen a couple times. The reason it happened for me was that the bird had set for a long time or moved some distance especially E/W. If either of these conditions occur I let the H sit without blades spinning for 15 minutes to get acclimated to the satellites.

 

[FlushVision]

<...snip>...

Wonder if the aircraft defaulted to return to home for some reason and just hovered where it was. I was close to it but in angle mode and obstacle advoidance was off

I would hazard that was what happened, particularly if your subsequent flights went without a hitch.

Your telemetry for that flight will tell the story.

 

[Dustoff]

I would hazard that was what happened, particularly if your subsequent flights went without a hitch.

Your telemetry for that flight will tell the story.

funny thing i only had one telemetry for that day and at least four flights

 

[robport]

I've had it fight me coming down a few times with the speed switch on turtle. I don't know it it's pertinent, but moving the speed switch up a little solved it for me...maybe a coincidence though because I can't explain it.

 

[NorWiscPilot]

I had a slightly different but still similar situation with my H520. It would not shut down upon touchdown, even after finally tipping over and having two motors stopped. The controller kept saying it had not yet landed.

Turns out the throttle stick would not go to zero or at least as close to zero as it should have. It would not calibrate either.

It must have been a glitch or dirty pot, or it just got scared. After ordering and receiving a replacement stick assembly, the original started working just fine.

Advice: check your sticks!

Jeff

 

[CraigCam]

That’s a dirty stick. Raising the slider adds expo and changes the scale of the stick input relative to voltage. Typically, the problem starts with left stick not responding to yaw commands in turtle. It can move to elevator next. A good cleaning of the pot solves this problem. If you have a suspect stick, I recommend checking it with hardware monitor pre flight and verify you get full stick input all around. You can work the stick around vigorously and often get it back to proper signal during this check. I also flick the stick to make sure center is returning all values to neutral. If none of that works then I do a thorough cleaning and then calibrate the ST16.
Your adding expo with the slider is a good solution to a flight behavior anomaly and something many of us have had to do more than once.

 

[Dustoff]

Here are the telemetry files for that day . Not sure why it only gave me one for the day when I had four flights