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Deadly Vortex + Dog House crash - Help pls!

Discussion in 'Phantom 2 Discussion' started by imprimatur, Jun 25, 2014.

  1. imprimatur

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    Hello guys,

    This is what happened: I was flying and having a great time. I had been in the air for around 10 minutes and my battery was at 50% at the time of the incident. Everything starts at 1:26 - falls over a roof, then ends up in the yard... and being checked out by an old dog.

    Now, here is the weird thing: at 1:28 it starts falling, very slowly, and then it goes crazy. I was not descending, not even in the first seconds. I understand that the Vortex Ring of Death happens when you are coming down fast... but I wasn't even descending. It did it on its own. :( I treid to get out by the "pulling forward technique" but I wasn't succesful.

    A couple of weeks ago something similar happened some 40 meters away from this place, but that time I was descending... not too fast, but at least I somehow can understand what might have happened that time. It was not the case this time.

    Do you guys think this might be caused by some magnetic disturbance, or props needing balance, or anything else? I am very afraid to fly when these things happen, because until now I can't see any pilot error.

    I would appreciate any help, hints, etc you guys can give me. Thankfully only 1 propeller was broken this time (the gimbal and battery both came off, but they are OK... you will see that in the video :x )

    Video: https://www.youtube.com/watch?v=EbIdHHc ... e=youtu.be


    Cheers!!!
     
  2. imprimatur

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    Re: Deadly Vortex + Dog House - Help!

    By the way, I was recording the FPV feed with iosd data... so you guys will be able to see what happened with all possible detail. This was my "maiden voyage" with my FPV recorder... lol :lol:
     
  3. ianwood

    ianwood Taco Wrangler
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    Well, one thing is for certain, this was VRS. Max descent rate was >3m/s. But, if you didn't command the descent, who/what did? There's nothing indicative of something else taking over or interfering. Did you command the climb that takes place just before? It looks like controlled flight into VRS.
     
  4. damoncooper

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    Looks like you were descending in place...generally a big no no, correct?
     
  5. imprimatur

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    I was wondering if perhaps this was caused by unbalanced props (can they cause that?) and/or some magnetic interference of some kind.

    I did command the climb that takes place just before, but not that crazy descent.

    Yes, except I was not descending. Would never descend there right over that house. That is why I am shocked, because this happened without any input from me.
     
  6. TodayTrader

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    Was your crash similar to this one in your opinion?

    Everything you say happened to me on this day. Then it happened again over water 3 weeks later and I never recovered it.

    https://www.youtube.com/watch?v=G3cYDw6IVn0
     
  7. imprimatur

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    Yeah, similar thing. Yours was more violent I think (fell faster, like a rock). However they are in similar in that both were hovering and just suddently entered a VRS.
     
  8. imprimatur

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    By the way, were your props genuine, brand new? balanced? :shock:
     
  9. TodayTrader

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    Factory props. Never damaged. Never balanced.

    I have not even mentioned my friend in Denver that had the same thing happen to him. Night flight and never recovered the equipment either. I really think something bigger is going on here that DJI needs to address. No pilot error
     
  10. ianwood

    ianwood Taco Wrangler
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    If you're saying the Phantom went into an un-commanded controlled descent that resulted in VRS and a crash, the props and magnetic interference are very unlikely causes. Using 3rd party props may increase the likelihood of VRS, but it doesn't explain the un-commanded descent.
     
  11. imprimatur

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    In my case they were genuine props. Very weird.
     
  12. ElGuano

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    Strange indeed.

    Did you have control of anything other than throttle during the descent? It looks like you were yawing around, was that manual?

    Any flight limits set? I notice OSD was blinking at >40m.

    Are you in the proximity of a no-fly zone?

    I'm not so sure it's VRS. It does seem to get pretty squirrelly near the end with gyrating 10 degree positive pitch and 3.9m/s descent, but that's only at the point of impact and before then, the descent seems controlled. VRS doesn't just happen if you go to 2.1m/s, you can oftentimes descend straight down 3x that fast and not hit VRS, it really depends.

    Does anyone recall what the OSD displays on flight mode if you run into the "descent on 50% battery" problem?
     
  13. imprimatur

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    When it was coming down I tried to move it forward and put the throttle down but I coudn't do it. It was all too quick so I don't know how much control I still had. It was in GPS mode all the time. I would say that until 1:27 it was still under full control.

    The flight limit is somewhere around 500 meters.

    No, the closest airport is like 35km away.

    Thanks a lot for your input. BTW did you watch this other guy's video (some posts above, https://www.youtube.com/watch?v=G3cYDw6IVn0 ) where he has a VRS without manually descending? It's kind of similar.
     
  14. imprimatur

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    By the way I just double-checked the settings in my Phantom 2. In the Assistant 3.0 max height is set at 400m, but on the miniIOSD the height range is set to 0-40m.

    That's why it was blinking. Now, I don't think it has anything to do with the descent, because this is just the iOSD and the Phantom is set to a max height of 400m.
     
  15. ElGuano

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    I did see the beach vid a while back, and I don't have a credible explanation for either. VRS still seems unlikely to me. The commonality between the two seems to only be a bit of wind (from your iOSD, enough coming from the right of the quad to constantly keep you at 5 degrees roll; in the other video, implied from the beach and kitesurfers). That would make a straight-down descent less likely to result in VRS. And while neither of you are up all that high or fall too far a distance, true out-of-control VRS often has crazy wobbles that pitch the frame well into view of a gimbaled camera. These seemed like brisk but steady descent to me...can't say for certain but the falls don't seem uncontrolled enough to be severe VRS.

    Yep, iOSD limits are visual only, they don't actually send/set commands to NAZA.
     
  16. ianwood

    ianwood Taco Wrangler
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    The 2nd video has no VRS just a sudden loss of lift. I'd suspect a power issue. And I agree with ElGuano, your descent was controlled and only hit VRS at the end.
     
  17. imprimatur

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    I am wondering....

    1- how effective was the update that limited downward speed to prevent VRS.

    2- I think it would be useful if you could limit downward speed thru software. In my case I wouldnt exceed 0.5meters per second (m/2)
     
  18. onthewave

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    I have had 2 different Phantom 2's do the deadly wobble during flight. It starts oscillating L to R back and forth violently descending uncontrolled to the ground and crash. Anybody know what is causing this? Props??
    here's a video of the crash

    https://www.youtube.com/watch?v=whBlSqsQcg4
     
  19. ElGuano

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    I fixed your URL - it was malformed.

    You should include 10-15 seconds of flight before the oscillations start as well. Were you on the descent? This video looks a lot more like "classic" settling with power. Wide side-to-side oscillations that build in speed and intensity, eventually overcoming the gimbal's ability to stabilize. Were you coming down when it first happens? Most of the time, it hits on fast descent, and once it starts, applying throttle doesn't get you out of it, you have to fly down and out laterally.
     
  20. Fyod

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    What turned the Phantom over on the side after the crash?
    How is it possible that we can see the battery (showing the status untouched)?
    If the battery fell out, how can the Phantom LEDs be blinking?