This is my 1st post.  I just want to understand why the  land mode does not always descent downward.   Because it has happened twice.  

1st flown the quad to very high altitude...

switch to land mode

quad responded the land mode and started descent 

few seconds later.. quad suddenly move backward in high speed instead descending downward.

I think I have about 5 seconds to attempt to take control back, so i tried ...

  - switched to  RTL while the quad is flying fast diagonally to ground,

  - quad is not responding to my RTL and continue flying diagonally to ground 

  - quad crashed - i noticed two of back arms broken off -  so it must be flying backward 

i reviewed several times dataflash log and not sure what caused failure.  

Can someone look at my log to give me some pointers why quad is flying away in land mode?

thank you for helping.  


2014-11-25 11-27-00.bin

2014-11-25 11-27-00.log

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  • Your log file is cram packed full of barometer warnings! They over lap so bad I can't acually separate the warnings/errors when plotting data in mission planner if showing the whole time period in one window. When zooming in on the second half there are loads of EKF warnings/errors.

    There are many glitches on you barometer alt and it doesn't seem to match GPS alt very well at times.

    You don't have much logging enabled, so I haven't spotted anything else.

    Darrin's advice is good.

  • When things go wrong, do not RTL.  Many times when it is flying erratic, it is a compass or a GPS issue.  Engaging RTL when it cannot figure out where home is can cause fly aways.


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