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Why did my drone auto-land itself?

Discussion in 'Pro/Adv Discussion' started by diveguy, Oct 7, 2015.

  1. diveguy

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    I'm definitely a new pilot, but have been having a blast with the Phantom 3 Pro. I've been honing my flight skills over wide open areas so I can keep track of it in the sky and to hopefully provide a soft landing if it goes down. I'm also watching a ton of YouTube videos and reading a ton of posts to learn more.

    Today I was flying in a very open area, and I flew the drone to the other side of a hill where I lost sight of it. The hill wasn't huge but did present an obstacle between me and the drone (which I assume was a bad move as it interrupted the signal). My iPad gave me the "Signal Lost" message and I could no longer see the camera view.

    I waited patiently for about 1 minute, hoping it would return, and after it didn't, I took a hike to the top of hill. There the camera view came back on and I was able to use the GPS to find it again - about 10 feet from a pond (phew!). In reviewing the video, the drone hovered for about 15 seconds after losing signal to me, then did a slow landing, straight down. In briefly hit a small tree and landed in dry grass, with minimal damage. It still works fine.

    I understand that when the Phantom 3 loses signal to my controller it is supposed to return to the original launching point using GPS, and it did have a GPS lock when launched. I'm trying to figure out why it landed itself straight down instead of returning. I'm assuming it was because it lost GPS signal to the satellites, but this was a very open area and I can't see how this would have happened. Would anything else have caused this? Should I be doing something differently?

    I posted a video of it here:

    Any ideas would be welcomed. I lose a lot of confidence when this happens, especially as a new pilot.

    Thanks!
     
  2. Nstrong48

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    Make sure your fail safe setting is on RTH and not hover or land
     
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  3. msinger

    Approved Vendor

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    A few things could cause this:

    1) You have the RTH setting in the DJI GO app set to land instead of return to home.
    2) The battery was critically low.
    3) Your Phantom was connected to less than 6 satellites at the time it lost the connection with your remote controller.
     
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  4. Bigskyflyer

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    Ditto.
     
  5. diveguy

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    Thanks - it was selected to RTH mode. I'm assuming it lost signal to me AND lost GPS from the satellites at the same time. It just seemed odd in an area where there was so much exposure to the sky.
     
  6. CloudsNeverDie

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    Get the log from the flight if you can (it's on your iPhone or iPad), that will tell you what happened. The Kp index was very high today, I didn't even dare venture out to fly, so that might have had something to do with it. Maybe it didn't have enough GPS satellites for the usual RTH.
     
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  7. diveguy

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    I have downloaded the log file and a link to download is attached here (hopefully). I don't know how to read/decode it, so if anyone has that ability I'd love it if you could take a look.

    Log file download: Hightail
     
  8. CloudsNeverDie

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    I took a look using Maps Made Easy - (my tool doesn't support .DAT files so well). The Phantom had 15-16 satellites locked while descending almost right up to the moment of the crash with the tree, so my theory doesn't explain it...
     
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  9. Bronson

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    How far was the home point to where the bird landed? Less than 20 m?
     
  10. diveguy

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    It was about 1500 feet distance (as the crow flies), as per Google Maps.

    I think tomorrow I will test the RTH feature in a field from close distances, just to confirm it's functioning correctly. I did use the feature 2 days ago from an altitude of 300 feet and distance of about 800 and it did its job perfectly.
     

    Attached Files:

  11. JP.

    JP.

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    Run the file on www.healthydrones.com u will see what happened exactly about gps battery and signal loss.
     
  12. L.Chaney

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    Same thing happened to me except mine descended into a tree top and died horribly.
    Sent to DJI and got a new bird in 7 weeks.
    I, like yourself did nothing wrong. Will it happen again? Only the shadow knows.
     
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  13. diveguy

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    Wow - the healthydrones.com site is fantastic! So much information there.

    I uploaded the files and went through all the results (below). Everything looks fine, I had 15+ satellites. The only thing that I see it that at the end of the flight, before it set itself down, there is a message that says "Downlink data connection lost for 1.1 seconds". After that, it landed itself.

    If you think you might know the answer, please take a look. I know I made the mistake of flying it behind a hill and losing line-of-sight, however I want to know that if I ever fly beyond range or if there is interference, etc. that it will in fact return home next time.

    Here's a link to the results at healthydrones.com:
    HealthyDrones.com - Innovative flight data analysis that matters

    Thanks.
     

    Attached Files:

    #13 diveguy, Oct 9, 2015
    Last edited: Oct 10, 2015
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  14. suck it up

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    Don't take this wrong,,,,,,,,,
    But
    RFMA...................
     
  15. tcope

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    What would be in the manual to answer this question?
     
  16. RedHotPoker

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    Yes, this made me laugh. ;-)
    image.jpeg

    RedHotPoker
     
  17. Mr.Spock

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    Don't get me wrong.... what's RFMA...? Restaurant Facility Management Avociation perhaps...?
    Or where you meant to write RTFM ...?
    So what is your analysis doctor? What's in the manual...?
     
  18. Peter D

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    I am sorry you lost contact with your drone. The only really important part of you post is do you realize it is illegal to fly out of line of site?
     
  19. WWK888

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    Wow, this post is 5 months old.


    Sent from my iPad using PhantomPilots mobile app
     
  20. neven

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    This is like the worst thread ressurection ever


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