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  1. Johan The Swede

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    I am currently in Lindos a village of Rhodes island in Greece.
    Two days ago I decided to climbe up behind Acropolis where there is a big cave to fly my phantom 4 that I have been flying for 120 flights back home without any problems. I have beegn testing all modes both indoors and outdoors in strong winds.
    This day I could not get any GPS position even though 50% of the sky was visible.
    I decided to fly anyhow as I have good experience of that from trying the modes out earlier.
    I hand started it and flew into the cave. When I flew out into the open and outside the cliff. I received a "max altitude reached" call and when I tried to bring it back it uncontrolled drifted and disconnected.
    Fortunately we later found the drone upside down with two arms broken after hours of search. I have the whole episode recorded if any of you are interested in seeing it I can upload the sequence when I get home.
    I guess lesson learned is "don't fly without GPS position"
     
  2. alokbhargava

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    Right, don't fly if its not ready to fly but sometimes you can't resist yourself. We all are adventurous.
     
  3. Johan The Swede

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    Just to add that I restarted the unit several times and waited. But for some reason it showed "ready to fly, no GPS"
     
  4. RémyHeli

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    Considering your Phantom works great and i.e. no sticker with metal particles fixed on the top of the craft (aka where GPS chip located)

    Civil GPS is a service with it's planned outages, interference testing and possible military activities. Not to mention other possible radio electric issue.

    GPS.gov: GPS Service Outages & Status Reports

    Anyway flight log analysis could tell maybe what happened, eventually.

    Sent from my iPhone using PhantomPilots
     
    #4 RémyHeli, Sep 26, 2016
    Last edited: Sep 26, 2016
  5. Johan The Swede

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    I tried to analyse why the incident occurred as I have not experienced this before.
    My experience before flying the phantom is with radio controlled helicopters without any stabilisation so it took me by surprise to loose control in the line of sight only 15-20 meters away from me after flying it in the cave for one minute. And no, I don't use any stickers or anything interfering with the signals. The P4 has not experienced any damage or collision before the incident.
     
  6. RémyHeli

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    Possibly after the cave the craft got GPS position and tried to align it's current position with it -> fly away. This is possible if you where not flying in Atti mode (Atti recommended when issues with GPS, indoor flight or ie flying under pine trees).

    Have you tried to extract the log to see if anything can get idea what happened? (how to extract log is already discussed in this forum).



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    #6 RémyHeli, Oct 2, 2016
    Last edited: Oct 2, 2016
  7. Greenenvey

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    I'm new to drones so sorry if this is a stupid question, but in this situation could you for to atti mode and be able to get control of the drone... Being so new to this, these stories scare me that the bird Can just fly away!
     
  8. Toyz

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    A cave with an air current inflow will have lower pressure than outside. Drone crosses the mouth where pressure drops and the phantom sees it as a massive altitude increase? Plausible?
     
  9. Cobs

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    Location:
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    Doesnt it have ATTI mode?

    I think most "satellites" are land based ;)
     
  10. RémyHeli

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    OP mention craft disconnected. In this case unable to toggle flight mode.

    Sure cave is not common scenario and with it's own characteristics incl. temperature.


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