Fly aways due to compass errors

cnorman · Feb 26, 2020

Hi there, new member.
I was flying my MM in low light. Took off and immediatly flew side ways in to a wall, breaking the front left arm. Managed to do a glue repair. Reset Compass and IMU.
Let glue cure then gave it heaps in sport mode at low altitude in my back yard. All seemed well. Including the camera.
Took it for a fly last night 30 seconds into the flight it started dropping with no response from the sticks, hit the ground (concrete) at some speed, bounced up and i was then able to resume control. Flew tentatively for another 7 minutes and all seemed well. I would appreciate members thoughts and advice on this. Cheers

Kilrah · Feb 26, 2020

Nothing to do with compass.
Did it have proper GPS signal?

sar104 · Feb 26, 2020

Kilrah said:
Nothing to do with compass.
Did it have proper GPS signal?

It could have been a compass error, or ATTI mode due to lack of GPS and low light.

Prismatic · Feb 26, 2020

cnorman said:
Hi there, new member.
I was flying my MM in low light. Took off and immediatly flew side ways in to a wall, breaking the front left arm. Managed to do a glue repair. Reset Compass and IMU.
Let glue cure then gave it heaps in sport mode at low altitude in my back yard. All seemed well. Including the camera.
Took it for a fly last night 30 seconds into the flight it started dropping with no response from the sticks, hit the ground (concrete) at some speed, bounced up and i was then able to resume control. Flew tentatively for another 7 minutes and all seemed well. I would appreciate members thoughts and advice on this. Cheers

Sorry to hear your troubles. For the best advice and info, follow the instructions in this post: Flight log retrieval and analysis guide
Experts are literally standing by to help! Good luck.

DanMan32 · Feb 26, 2020

sar104 said:
ATTI stabilizes pitch, roll, yaw and altitude. Just not position.

Isn't that what I said?

Kilrah · Feb 26, 2020

sar104 said:
It could have been a compass error, or ATTI mode due to lack of GPS and low light.

I'm thinking more about no GPS and the VPS getting confused by the ground's appearance due to the low light since I had exactly the same with my MM. VPS does tend to get confused and think it's moving when it's not, and thus compensating the other way and throwing itself away.