Iris falls out of the sky


I have an 3DR Iris. And has been flying with it since january without major problems.

Now suddenly it will just fall out of the sky after flying for one or two minutes. I have attached the logs from the last three flights where it happened.

I started out with a fully charged battery hovered at app 7 meters height. Suddenly it looks like the two motors on the right side just turned of and Iris will fall/crash down on it’s right hand side. Iris are flying around perfectly normally until the motors just turns off…

Can anyone tell me what the problem is?

Best Regards

I can see two issues:

  • “Err: Flight_Mode-3” indicates a failure to enter requested Flight Mode.
    Are you trying to switch to Auto without having a auto mission defined?

  • You are flying with a hover throttle that is > 70% and therefore outside the recommended range. You are even close to 80%, which is just plain dangerous ( … ly-safely/). You have to give more throttle to keep IRIS flying than you have available.

Reasons why this used to work and now suddenly doesn’t anymore:

  • Lipos loose performance with every charging cycle
  • Outside air temperatures might be higher
  • You might be flying at a higher altitude flying field
    All of the above have influence on how much throttle you need to give for keeping a quad in the air.

Reduce weight (e.g. take off the Gimbal) or increase lift power ( … batteries/).

Thanks for the reply and the two problems you found.

-“Err: Flight_Mode-3” indicates a failure to enter requested Flight Mode"
I did not try to switch to an auto mission and I don’t have any missions loaded. So It can’t be the problem.

  • "You are flying with a hover throttle that is > 70%"
    I don’t have a gimbal. I was flying only with the front mounted GoPro. The Lipo is brand new with only 5 flights on it. The outside temp was lower then normal 20 deg C. I was flying right next to the ocean so it’s a low altitude.

I just upgraded my Iris from the developer edition with the DIY kit and at the same time relocated the Pixhawk. When I relocate the Pixhawk do I need to change some settings?

Any other ideas what went wrong???