Hi,
yesterday my hexacopter crashed due to a complete motorstop from about 50 m.
I was flying sideways holding the stick full way to the left in POSHOLD when it happened. After the crash the lights on pixhawk where still on. The logfile says err: cpu 1 and err: cpu 0 at the beginning of the file and err: crash check 1 at the end. All data stops in midflight.
If anybody is experienced with datalogs it would be nice if you could have a look into the enclosed logfile.
I dont dare to fly anymore before I now why this has happened.
Thank You in advaance
Replies
The parameters are in the .BIN anyway, the problem with final understanding of what's happening.
Yes I also had a 2 years period when nothing happened although I flew a lot. Unfortunately times have changed since then. Very often it is not the copter to blame but the man behind the sticks ore the man who built the copter. In my case it is the same person. As I am flying commercially every now and then it would be better for my nerves to find out what was wrong.
Would it help to have a look at the settings? Maybe I have done something stupid there.
Well, I flying them is my fulltime job, and had no accident the past 2 years. And never an unexplained one.
I mentioned that throut fell, (throttle demand) - there is no indication of a battery problem. (then you would see throut be high)
seeing individual motor throttle could have helped too (RCOUT)
now and then I see people that had only one bad/noisy power source for the AP, and BEC/brownout makes the AP reboot, (causing it die midair) - but this is not one of those cases.
No, there was only a little wind. But I have to confess that I used a lipo which had fallen from a table and had a little ditch. Although there is no sign of any problems with that lipo. Could the current drop be a result of foulty lipo?
I admit this accident makes me a little nervous as long as I dont know the reason for that behaviour. I have 3 copters using Pixhawk and I dont dare to fly them any more. Besides I had a simular accident a few years ago with apm 2.6. After takeoff the motors stoped suddenly. Next flight everything was OK. I never found out what the reason was.
You can fly in any direction regardless orientation, there's no difference in you flying sideways vs forward. So that was not a mistake.
Was it very windy , possibility of vertical winds ? (something that could explain the throttle drop with no drop in altitude ?)
Hallo Andre K.,
thanks for your help. I will switch on RC logging in future. So I think my mistake was to fly fast by using roll instead of pitch. But I dont understand why the desired roll was not reached. The stick was full left all the time. POSHOLD was on all the time.
So at the moment I understand that full roll for longer time will result in a crash if it is done with POSHOLD engaged.
It was unable to get desired attitude for several seconds, trigging a crash-check
(crash was detected due to the fact that it did not get near desired attitude - so it disarmed)
it was almost three seconds where roll was only -7deg , while desired roll was -40
Since you for some reason do not have RC logging, it's hard to figure out what went wrong, but throut got reduced as the attitude error grew.
Screenshot from 2016-10-20 09-42-11.png