Unstable Quadcopter

My Holybro Pixhawk 1 quadcopter takes off ok in stabilize mode, but once off the ground and in loiter mode, its behavior becomes unstable. It does not like stabilize mode, and I am forced to put it in land mode and bring it down. Everything seems fine on the ground. Here is the flight log:

That’s not a flight log it’s Auto Analysis of one which has very little value. Post a link to the actual .bin log file.

I’m not sure how this works. Post a link to it? Can I copy and paste the file somewhere?

Not here, no. Use a cloud service of choice(Dropbox, etc) and post a link to it here.

https://drive.google.com/file/d/1S3KC5zgqjd-rsfuaRdhWy1QmJn1uRNCE/view?usp=sharing

It doesn’t look like it’s flying in this log. Can’t do much with that.

https://drive.google.com/file/d/1AcE3gd21QUGCuKZgyUBVIkg5r7yLU61m/view?usp=sharing

That file has an access requirement. Why don’t you open it in Mission Planner, graph the Baro>Alt and confirm it’s a flight log useable for troubleshooting your problem. And then remove the access requirement.

How would I do that?

By starting here: Logs

And do not forget to update to ArduCopter 4.2.1

I went to the logs page. How do I open a .bin file to do something useful with it? How do I open it in Mission Planner? Thanks.

Go here and select the Review a Log button. Presumably you downloaded and saved the log from the Flight Controller 1st.

Ok. Did that. I have a log browser window open.

There is a red and blue line diagram of the flight path. What I would like to know is why the aircraft stumbled in mid-air when I changed flight modes from stabilize to loiter and then shot up in the air when I switched back to stabilize. It would not hold loiter. I had to bring it down under land mode. Thankfully it came down slowly.

Post a link to the log where it’s flying.

There was a line in the text version of the log that stated a large magnetic variation occurred, but I can’t imagine why that would be. I have seen the same effect occur on previous occasions.

As I said that message has little value.

See if this works: https://drive.google.com/file/d/1S3KC5zgqjd-rsfuaRdhWy1QmJn1uRNCE/view?usp=sharing

There is nothing top see in this log and it’s in Stabilize there is no Loiter. Make another flight, fly it around and post that log.