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First Crash Why?

Discussion in 'Phantom 2 Vision + Discussion' started by sprouseod, Sep 7, 2014.

  1. sprouseod

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    Hello everyone, this is my first post to PP but I have lurked and gotten a lot of great info.

    So Today I had my PV+ in the air. The battery was getting low (around one minute) I was maybe 100 feet from landing. The conditions were a bit windy. As I descended the PV+ started to oscillate side to side quite significantly. I seem to have no control over it. It crashed into the grass pretty hard but a test flight later with a new battery showed there to be no problems as far as i can tell. My question is how did this happen? I had 7 sats. I was landing it myself, but the closer it got to the ground the more out of control it got. As far as I can remember, I did not let go of the altitude stick on the left. Maybe I should have just let go of the sticks and let it stabilize?

    Any info would be appreciated

    Richard
     
  2. Meta4

    Meta4 Moderator
    Staff Member

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    Probably the main factor is your battery strength. You really want to get the bird down before you have 1 minute indicated.
    Battery power is different from petrol in your car's fuel tank.
    As the battery discharges, the voltage drops and the battery is unable to deliver the power you think you have.
    The last 5% is not as strong as the first 5%.
    By the time you get to 1 minute there's nothing in the tank.
    I'd suggest landing before 10%.
     
  3. Mako79

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    Sounds like VRS a bit. Spiral down slowly and don't descend thorugh the prop wash and keep moving laterally.

    If you are landing and real close to ground:
    windy + loss of satelites + turbulence = tip over/crash.

    Closer to the ground means more turbulence from props and less satellites as the ones from the horizon are no longer available. This will make the phantom go ATTI mode and it will move with the wind. It just takes a small gust and goneskies.

    Also, don't do CSC on power down. Use the left stock down for 3-5 secs. This is much more stable as the CSC puts the revs out of balance = tipover and cracked props.

    Just catch it.
     
  4. DownunderPhantom

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    You can hold the left stick down then complete the csc with the right stick, no revs, no tipover, very smoooth power down...
     
  5. RipperFox

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    Sounds like a textbook VRS

    Never decend straight down quickly. Always move in any direction (forward, back, side to side) while decending quickly. This gets you out of you own rotor wash...

    Look on Youtube for VRS. There is alot of good vids to explain what is happening.

    the Marine Corps new Osprey (two rotor helo/plane) wash plaged with this very thing.
     
  6. Tokyopav

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