Welcome to InspirePilots.com

Join the leading DJI Inspire community for free!

I think VPS contributed to a crash

Discussion in 'Inspire 1 Discussion' started by Ezookiel, Mar 26, 2016.

  1. Ezookiel

    Joined:
    Aug 28, 2015
    Messages:
    188
    Likes Received:
    65
    Location:
    Canberra - Australia
    I have been going over the flight log and replaying in my mind, my first crash of an Inspire last week, and I'm at a bit of a loss to explain it. I want to run past people here, whether my theory on the crash holds any weight and see what you all think.

    I had a series of shot to pull off, where I had to fly vertically straight up, and straight back down with the back of the drone very close to a large tree. I stood at the very edge of the tree to use myself as a marker - provided I didn't fly behind myself, I thought that I should be fine. I flew straight up, and then came straight back down. As I got to about a foot above my head, I stepped back in under the tree, with the plan that I'd bring the Inspire down to where I had just been standing. Instead the Inspire followed me in under the tree. I have gone back over the flight logs, there was no stick input at all at that point, as I had paused at that spot as I got myself out of the way.
    There were wind gusts, but not really enough to explain it moving that far. It probably moved a good 1-2 feet.

    My suspicion at the moment is the VPS treated me as its reference point, and when I moved backward, it has mistaken my backward movement as the Inspire drifting forward, and has corrected and sent the drone backwards with me. Is this possible or likely, or am I just the unfortunate victim of a badly timed drift/wind gust?

    I throttled forward immediately, but she tipped upside down and fell onto the tarmac almost perfectly upside down (scuffed the flat centre top of each QR propeller almost perfectly equally. I've broken the plastic gimbal mount, and the aluminium ring that the wishbones mount to, is bent at both sides where the wishbones are attached. Any other damage is yet to be determined when I can get the unit to a repairer - that's just what can be seen with a look over from the outside.
    To say I'm a little gutted is an understatement.
     
  2. Kilrah

    Joined:
    Feb 3, 2015
    Messages:
    1,881
    Likes Received:
    728
    Yes, that's 100% what it's there for.
     
  3. Ezookiel

    Joined:
    Aug 28, 2015
    Messages:
    188
    Likes Received:
    65
    Location:
    Canberra - Australia
    Note to self - turn OFF the damned VPS then.
    Sadly it was a deliberate choice to have it on. I fly over water a lot so turn it off a lot. But this job as I went over the preflight, I thought about VPS and left it on deliberately. One of those "What harm can it do?" moments where I came up with the wrong answer.
    I never thought about the flight down directly over myself.


    Sent from my iPhone using Tapatalk
     
  4. Kilrah

    Joined:
    Feb 3, 2015
    Messages:
    1,881
    Likes Received:
    728
    TBH for me the mistake starts here, why would you stand in the worst possible place to be in should the thing have a problem?
     
    alabamajack137 likes this.
  5. Ezookiel

    Joined:
    Aug 28, 2015
    Messages:
    188
    Likes Received:
    65
    Location:
    Canberra - Australia
    Fair point, but I was using myself as a marker to ensure I didn't back into a tree. I trusted the fact that because I was staring right up its underside the whole time, that I was going to be able to get out of the way if it went bad. Which I proved to be the case when it did go bad only a foot above me when it followed me and I still didn't get hit.


    Sent from my iPhone using Tapatalk
     
  6. The Editor

    The Editor Moderator
    Staff Member

    Joined:
    Aug 7, 2013
    Messages:
    6,722
    Likes Received:
    3,878
    I would say your suspicions are correct.
    Here is an example of how the VPS can be easily fooled. It might be a shadow, or a leaf or in your case, you but people should be aware of its idiosyncrasies.
    In this case it's on a Phantom but the theory is the same.

     
    slim.slamma likes this.
  7. Harryscopic

    Joined:
    Dec 21, 2015
    Messages:
    29
    Likes Received:
    5
    Location:
    Spain
    Thanks for sharing Ezookiel, we can all learn from these mishaps.
     
    slim.slamma likes this.