My copter with PIXHAWK was working great after finishing autotune for all 3 axis. I flew it several times with no problem. Today, I took off as normal in Alt Hold mode and it was very jittery and was erratic with the altitude too. I tried to land it but it came down rather suddenly and just flipped over.
I will attach the log to see if someone can help me understand what suddenly went wrong. MissionPlanner.log (500.1 KB)
I found your log was truncated with too many errors so I couldn’t have a look.
Is that the flight log, .bin file, from the flight controller?
Yes, I downloaded the .log file using Mission Planner. I don’t know how to download the .bin file.
Here is a fresh download of the log file.00000008.log (688.4 KB)
From what I can see your throttle input value was very high and your baro and ground speed values show that it was a nearly static flight.
So you are running on 3s, with a massive voltage drop under load, nearly a volt.
Was it a brand new battery?
From a quick look,
Your problem seems to be not enough power and/or being unbalanced.
Your throttle is pegged to the max but the copter is reluctantly climbing with motors 3 and 4 being pulsed to minimum for most of the flight.
Were you fighting a breeze?
As @bendead noted your battery is barely keeping up with such a large voltage drop and you haven’t set up current measuring so I can’t tell you any more there.
For further help you really need to give us more detail about your setup and the flight in question.
You both hit the nail on the head. It was a 3s battery with a weak cell. I installed a new fully charged battery and it flies great again.
Thank you so much for the help.