Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Witnessed a Vision+ crash - don't believe it was pilot error

Discussion in 'Phantom 2 Vision + Discussion' started by tscott, Sep 1, 2014.

  1. tscott

    Joined:
    May 21, 2014
    Messages:
    15
    Likes Received:
    0
    Video here:

    https://www.youtube.com/watch?v=TMYqY0j9piw

    Background:

    My dad has a Phantom 2 Vision+ -- same as me. He had an incident a couple of weeks ago where it he was flying it in-town in his backyard and it ignored his RC controls and crashed into the ground. The camera was protected by the camera guard he bought from another user on this site. He spent the past week getting things back in order - mainly repairing a few ECS boards. I was over at his place on Friday (8/29) to video the first flight in case anything went wrong. He flew for about 15 minutes without incident. As far as we could tell, he was back in business. On Saturday, I was at my in-law's farm and invited him out to fly around - to help shake that paranoia feeling. The first flight at the farm went without incident. He flew for about 15 minutes. No troubles. No worries.

    On the second flight out he flew for about 5-10 minutes. No troubles initially. I noticed that as he was taking some pictures of the setting sun, it wasn't sitting in a rock solid position like I'd expect -- especially since he had 8 satellites being reported in the DJI app and he was in GPS mode. I whipped out my camera to video things just in case he had another issue. Sure enough, it moved some more, and then went into a big circle before accelerating forward and dive bombing into the ground. All the while, he did not have his hands on the controls and had 8 reported satellites. The video of the crash cuts out since I got startled and started running to the corn field where it ultimately crashed.

    Point 1: I've flow in this area numerous times with my quad without incident.
    Point 2: We calibrated the compass before take-off.
    Point 3: I don't see how pilot error would be involved. It should have been rock-steady in its position.
    Point 4: When this happened previously, the quad ignored the RC controls completely. I have my doubts that he could have done anything to prevent this crash from happening.

    He's going to contact the dealer he bought it from, but doesn't feel too confident that he'll get anywhere on that front.

    Is this a warranty issue? Is the control software on the platform buggy? How do you go about troubleshooting something like this?

    If it's not covered, that'll royally suck. $1300+ down the drain. This makes me super-paranoid to fly my quad now. :p

    --tim
     
  2. Dirty Bird

    Joined:
    Apr 15, 2014
    Messages:
    0
    Likes Received:
    9
    Location:
    Glen Burnie, MD - USA
    Re: Witnessed a Vision+ crash - don't believe it was pilot e

    Yuck... All I can think of is there had already been an abnormality in the previous control loss crash. Clearly some component was failing, at least on an intermittent basis. This latest crash looks like it is going to be an expensive repair. Not sure what luck you will have with the dealer depending on how long he's had it, and the prior crash?
     
  3. cahutch

    Joined:
    Jul 8, 2014
    Messages:
    558
    Likes Received:
    4
    Location:
    Sonoma County, CA
    Re: Witnessed a Vision+ crash - don't believe it was pilot e

    Sorry about the loss. I've been there, but fortunately my camera survived.

    Hard to tell from that video, but the "swirling" or circling behavior is normally caused by compass error.
    The problem would normally happen right away though, not 10 minutes into the flight.
    I don't see how there could be any compass interference at that altitude.

    Did you calibrate the compass before that flight or recently? Or at least after the last crash?
    Did you recalibrate the IMU after the last crash?

    I can't see the indicator lights in that video. They didn't change color did they? Any red flashes? No chance the S1 switch got moved?
     
  4. Fourblade

    Joined:
    Aug 9, 2014
    Messages:
    408
    Likes Received:
    67
    Location:
    Warwickshire UK
    Re: Witnessed a Vision+ crash - don't believe it was pilot e

    That's a really painful video to watch....

    I never feel completely at ease when my P2V+ is in the air.. I always feel a bit nervous...always...(does any owner not feel this?) but, and it's just a question - if there was a massive compass error would going into ATTI mode have possibly/potentially helped or (if it was a compass malfunction) would this be too catastrophic an error to avoid loss of control and a crash?
     
  5. cahutch

    Joined:
    Jul 8, 2014
    Messages:
    558
    Likes Received:
    4
    Location:
    Sonoma County, CA
    Re: Witnessed a Vision+ crash - don't believe it was pilot e

    I'm pretty sure a quick switch to atti mode as soon as you notice that kind of problem should help regain control.
    In GPS mode, in the absence of control input, it tries to maintain position, so a GPS or compass error can cause it to fly off on it's own. If the software thinks it's out of position it tries to get back to where it thinks it should be.

    In atti mode it doesn't have a mind of it's own and no motivation to move without control input. It does rely on the IMU in atti mode though so IMU calibration is very important.
    If the IMU is calibrated off level, GPS mode can mask that since it will still hold position. A large IMU error could cause it to tilt in atti mode and thus to drift fast in one direction.

    In theory, a compass problem in Atti mode might make it change it's facing direction randomly but shouldn't cause it to move in any direction.
     
  6. clingermac

    Joined:
    Aug 19, 2014
    Messages:
    38
    Likes Received:
    0
    Re: Witnessed a Vision+ crash - don't believe it was pilot e

    I have had 2 of the exact crashes you described. The second one took out the camera's ribbon cable and I believe the WiFi. Good luck dealing with those guys in China.
     
  7. tscott

    Joined:
    May 21, 2014
    Messages:
    15
    Likes Received:
    0
    Re: Witnessed a Vision+ crash - don't believe it was pilot e

    Yep. I mentioned that we calibrated things in point 2 above.

    Yes, the IMU was calibrated after the first crash.

    Honestly, it was too far away to see the colors on the quad. Everything happened so quickly that he didn't have much of a chance to do anything.

    --tim
     
  8. Panamon Creel

    Joined:
    Jul 31, 2014
    Messages:
    229
    Likes Received:
    0
    Location:
    Central Mexico
    Re: Witnessed a Vision+ crash - don't believe it was pilot e

    Hmmm my guess would go towards gyro or Motor/ESC issues
     
  9. cahutch

    Joined:
    Jul 8, 2014
    Messages:
    558
    Likes Received:
    4
    Location:
    Sonoma County, CA
    Re: Witnessed a Vision+ crash - don't believe it was pilot e

    Oops. Sorry, I guess I missed that.
    I think you're right. Doesn't look like pilot error in this case. It's every pilots worst nightmare, Equipment failure.
    I think you're on to something there. Even though it kind of looked like a compass error, nothing could have interfered with it at that altitude.
    Something had to fail mid flight and an ESC is probably the most likely.

    If an ESC overheated and one motor slowed down rather than just stopping, it would start to drift, then the system would try to hold position by reving motors the opposite direction. That might cause it to arc a half circle like that and then crash. It would explain the first crash also if the ESC runs normally until it gets hot.
     
  10. ToThePoint

    Joined:
    Jun 4, 2014
    Messages:
    618
    Likes Received:
    1
    Location:
    Antwerp, Belgium
    Re: Witnessed a Vision+ crash - don't believe it was pilot e

    I had a similar incident with a GPS module that had a broken connection.
    I had a crash also but i know now that i had to set the bird into ATTI mode as suggested.
    If things go out of the normal behavior, go into ATTI mode.