Lost Copter - Need help with telemetry logs

Bad news, it’s at the bottom of a lake. No data flash logs.
Good news, it’s at the bottom of a lake. No personal or property damages other than my pride.

Problem: First off, not blaming this on Ardupilot. I had been fooling around with some parameters while trying to install a sonar altimeter and I’m fairly certain that is the source of my altitude issues. I have telemetry logs, but don’t fully understand all the data I’m looking at. To make things worse, my telemetry logs are split between QGC & MP. Couldn’t control via radio and modes weren’t working properly so changing GCS was the last ditch effort to solve the problem. I have also converted both sets to kmz files and can guarantee that it’s at the bottom of a lake now. I want to try and determine what went wrong and how to gather data to prevent this from happening again. I need some help analyzing telemetry logs. In mission planner, I can view the logs, but there is no label on the y-axis for most data. Can I enable this, or is there somewhere I can find the standard units for specific variables? I’m trying to determine why it would not come back down, why it drifted when I put it in Land mode, and why it would not return the last few times I placed it in RTL mode.

Scenario: I took off a few days ago and when I switched into Auto, the drone went sky high. Switched modes to PosHold then to RTL and it came back to my position. Switched to Land and nothing happened. Went back to PosHold and tried to bring it back down, but it just stayed up there (didn’t climb anymore, but wouldn’t come back down). Went to Land again and it maintained altitude and started drifting. Kept trying different modes to bring it down, but nothing worked and it continued to drift. Eventually I lost sight of it and the last known GPS location was the middle of a lake.

I’m sorry to hear that.

Can you post the logs?

Did you check if the sonar was working when you configured it?

I actually disconnected the sonar before the flight because I could not get it to work. I forgot to reset the parameters back to barometer. I think that is the reason for my altitude issues, but I’m still confused about why it drifted away from me.
1stHalfOfFlight (QGC).txt (1.1 MB)
2ndHalfOfFlight (MP).txt (232.8 KB)