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What the heck happened. P2V+ 45 degree crash into ocean.

Discussion in 'General Discussion' started by Aerial Entertainment Studios, Jul 2, 2014.

  1. Aerial Entertainment Studios

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    Hello all

    I purchased my P2V+ in Hong Kong and have been flying around the world with it for 2 months. No issues whatsoever in Fiji, Hong Kong, Indonesia, Thailand. Sample footage here:

    https://www.youtube.com/watch?v=4B1YPD5b5lk

    However, I brought it with me to my home country of Canada (Quebec area) and the unit compass calibration got so out of whack that it decided to go for a dive in the ocean. It's now gone and I have lost $1500. I would need your help in understanding what happened as I've been flying this thing for months without any issues and pondering the option of buying another unit.

    Here are a few more details.

    - Initial takeoff was followed by a circling that got bigger and bigger (and faster) unless I intervened to stabilise the unit.
    - After about 10 flights, the P2V software detects a compass calibration issue and requires an advanced calibration.
    - I complete the advanced calibration (all confirmed in the software) and take the baby out for a test flight. Same issue occurs, but with less magnitude.
    - I take it to the ocean front and take off with no issues. Stable for first 2-3 minutes (altitude about 100 feet) and then enters a high speed 45 degree dive straight into the water. I try to recover by sending the unit straight up but with zero response from the Phantom.

    On the bright side, no one was injured (this has always been my worst fear), but at the same time, I don't believe I made a piloting error.

    I am seeking for your opinion on what could have potentially happened. Was this an engine failure, compass issue, or something else?
     
  2. The Editor

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    Beautiful scenery but..... look at that horizon drift on your gimbal :eek: - Something is wrong there!

    I would say your flyaway was caused by magnetic declination error as evidenced by the toilet bowl effect you were suffering (ever increasing circles)
     
  3. Aerial Entertainment Studios

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    Thanks for your observation. Someone else told me about this as well and I find the whole issue unsettling. This means I need to fly in attitude mode and rely on GPS data only when the unit needs to come back home.

    What do you mean by 'horizon drift' ? Is this referring to the fishbowl effect?
     
  4. Mal_PV2_Ireland

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    Magnetic declination could have been the problem alright, another possibility is the compass got so out of whack from an xray machine. My p2v went to dji Germany for repair where they tested it before sending it back to me. On my first flight it started acting a bit crazy at 10 ft altitude, going in circles. Magnetic declination isnt a problem in this part of the world so whatever went wrong happened in transit. I immediately took it home without flying further and hooked it up the the laptop. The compass mod reading was off the chart with a reading of 4500 where it should be 1200-1800. No amount of basic or advanced calibration would bring the values down. In the end I had to reset the compass doing the magnet trick then I ran the calibrations which fixed it and I havent had a problem since in the last 5 months. Just note that the magnet trick is an absolute last resort and all other avenues must be tried first. Did you notice what your compass mod values were? Could they have been over 1800?
     
  5. Aerial Entertainment Studios

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    x-z axis were at about +400 and the y axis was at -289 (once I completed the advanced calibration). Mod value was about 1400.

    The fishbowl effect was not there prior to the software update I did to the new version with waypoints. Could this be related?
     
  6. ianwood

    ianwood Taco Wrangler
    Staff Member

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    X-ray machines have zero impact on the compass. If you travel with your Phantom, keep the compass away from sources of strong magnetism. Neodymium magnets like those in the macbook mag safe connector and speakers are common culprits. X-ray machines do not contain any powerful magnets nor do X-rays themselves cause any harmful effects to the compass.

    OP, your issue is magnetic declination. I think you already found the thread.