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Crash prevention...

Discussion in 'General Discussion' started by OverheadAerial, Aug 1, 2014.

  1. OverheadAerial

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    Being a brand new owner of a P2 with H3-3D, Futaba T8FGS and Field Monitor I am concerned over my lack of experience. Before flying it today, for the first time, I did everything I could to make sure everything was perfect even doing an advanced calibration even though it was test flown before shipment and not flying with the H3-3D. Everyone here would of laughed at me today as I got ready for my first flight, I had paperwork stuck in all of my pockets for reference if needed.

    But after reading the forum for a couple of days I've realized there are some crashes that could of been avoided with experience. So that's the basis of this thread. Based on your experience through flying or research, what are the main causes of fly aways, toilet bowl effect, death wobble or any other crashes and how could they have been avoided?
     
  2. sidebox

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    Hey, welcome to the most fun toy ever. Always calibrate your compass before every flight. Never panic if you lose control, usually getting some altitude will keep you safe. Make sure you have plenty of satellites before taking off. I make a plexiglass guard, which can help protect your camera and gimbal in the event of a hard landing or crash. You can find it in my signature. Another guy on here, named fastsmiles, makes a carbon fiber version, as well.
     
  3. ProfessorStein

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    Hmmm. I would actually AVOID recalibrating your compass before every flight. It's too easy to introduce errors if you calibrate too often.

    I suppose there are two schools of thought on this... but there really shouldn't be any reason to calibrate your compass unless you:

    1) have travelled and are now more than 100 miles or so from the last location your flew your Phantom

    2) have opened your Phantom and/or replaced components

    3) notice an unusual movement pattern while your Phantom is hovering (such a large circles, etc)

    But definitely... always make sure you have a good GPS lock on a descent number of satellites, and that the Phantom has indicated that it has set the home position.
     
  4. IrishSights

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    Never descend straight down. Even with the maximum descent rate set fixed the firmware Vortex Ring State (VRS) can still be initiated. Always descend at an angle or while flying a circle.

    Keep it line of site (LOS).

    Avoid taking off with tall objects nearby, search out wide open spaces. If the tallest object in your flight path is taller than 20m fly straight up after takeoff to that height and reset your homepoint in the air. This is to avoid hitting a tall object if you ever have to or the Phantom initiates a Return To Home (RTH) This needs the firmware to be in Naza mode, which you would need to read up on.

    Give full power on takeoff especially if windy.

    Don't fly in strong winds.

    Fly gently avoiding sudden sharp moves of the stick.

    Practice catch landing. Useful at the very least in stronger or gusty winds.

    Make sure your Phantom is positioned on a level surface for takeoffs and landings. A portable helipad is handy.

    Avoid takeoff from metal surfaces, be aware there may be rebar in the concrete below you. These can influence your compass.

    I am sure there is more...

    Sent from Samsung S4 via Tapatalk
     
  5. chuddly

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    The above advice is good...
    I tend to agree with ProfessorStein about the compass.

    Another thing is ...TAKE IT SLOW AND EASY. I think alot of people do pretty good their first flight or 2 or 5 or however many. Then they start thinking "this is pretty easy. I got this flying thing down pat". Then they start getting more daring and flying harder and faster and their skill level it not to a point that if something were to go wrong their reactions would be the right ones.

    Start in a wide open area and get used to how the quad flys. then get a couple pieces of long PVC and stick them in the ground (or make a base for them). This gives you something to fly around while will having an escape route (going up) if you feel like you cant do something.

    Unless you are under trees or power lines or something remember this "When in doubt throttle out". In other words if you are flying close to something and you get turned around and dont know which way to go...normally up is a good option because there is generally open air. This is not ALWAYS true but its good to think in 3D.
     
  6. helishmeli

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    When you say to descend while going in a circle, do you mean like a pirouette? Or like flying in small circuits?

    Also, you mentioned "Line of Site." Are you saying to always land in line of site? Or do you mean always keep it at line of site? (The reason I ask is because I mainly fly fpv)
     
  7. EMCSQUAR

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    A) Death Wobble - descending to fast (AKA Vortex Ring State or prop wash) new software updates have addressed that and decent is now much slower
    B) Toilet Bowl effect - is lack of proper compass calibration and/or IMU calibration. Usually is compass is not cal'd properly you'll get this effect or if compass #s happen to rise because you're near metal/magnetic source of have been near. Mentioned above - if flying in new or distant location make it a habit to compass cal.
    C) Fly aways - most, not all are usually related to pilot not aware of Phantom systems - not knowing light sequence, calibrations, different modes, flying within wifi sources, flying within reflected wifi sources, flying near magnetic sources, the list goes on.

    Best advice know your Phantom and it's cababilities, read and understand the manuals and start small and move up to more advanced flying techniques. Read the forums and know what to look for in weird occurances (there's plenty listed) Fly it and enjoy it just not recklessly. Most crashes begin with - "I was just showing some mates..."
     
  8. IrishSights

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    Actually I meant 'line if sight'. That is, always you or an observer (if FPVing) have unaided line of site with your craft. This is only my advice, others I know do otherwise. This is actually the law where I live for flying FPV.

    The idea of descending the way I suggested is just to keep it moving forward and to keep it fairly close to you.
     
  9. OverheadAerial

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    Please excuse my ignorance but I'm not sure what you mean when you say, within wifi sources, reflected wifi sources or magnetic sources. Would you briefly explain? Thank you.
     
  10. helishmeli

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    I am too curious about wifi interference. It scares the **** out of me. Has anyone here had a phantom fly away, crash, or lose control because of wifi? (or know someone who did)

    I generally only fly above water or fields, I hate flying above/near civilization because I am so worried I will be accused of spying or something. But when I update something on my phantom 2, like put new landing gear on it, I will test it out outside my house. This is so I at least know the wiring is correct and stuff before I drive away with it.
     
  11. helishmeli

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    Okay, I see. This is no doubt the most safe way to fly fpv; to have a friend maintain eye contact with the quad. As far as legality, I wonder if binoculars would help. For instance if I fly fpv and go too far out so that my observer cannot see the quad anymore, I wonder if it would be okay for him to use binoculars to maintain contact with the quad. I am curious because I do sometimes fly fpv to the point of where I cannot see the drone anymore, at least not with the bright sun next to me.
     
  12. damoncooper

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  13. helishmeli

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    I read it all and am a little confused as to how it ties in. Are you saying I should have another fpv camera in addition to the gopro?
     
  14. damoncooper

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    No, just beware VRS
     
  15. helishmeli

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    what's vrs
     
  16. IrishSights

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    In the UK it has to be unaided line of sight according to the regs. A bright strobe on the craft may aid getting it back in your 'eye' if you take your eye off it for sec and lose it. However i never got a strobe bright enough and I have even tried proper Zenon strobes!
     
  17. EMCSQUAR

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    VRS = Vortex Ring State or more commonly known as prop wash. When your descending at a fairly rapid rate your props are literally creating a vacuum below aircraft. Once into that vacuum it starts to fall faster adding throttle only makes it worse. To get out of it you move aircraft forward or to the sides. http://en.wikipedia.org/wiki/Vortex_ring_state
     
  18. EMCSQUAR

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    You might be more cautious flying over water when water is calm because surface can reflect yours and any other nearby wifi causing loss of stabilty. We see it often when flying over frozen lakes in winter or over "glass like" lakes.

    I'll try to keep this simple. Wifi interference can come from a number of sources. Residential internet routers, commercial buildings (some have a wifi protection band set up to prevent hacking) even as simple as a GoPro wifi remote control can disrupt your flight. Think of it this way - if you're flying and you encounter a wifi frequency close to your transmitter frequency, which ever source is closer your Phantom is going to react to it. IE: Turn on GoPro wifi then TRY to fly - you'll see (not always but in most cases) it fly erractically. Here's a test I did weeks ago using wireless mics at a festival - https://www.youtube.com/watch?v=RvNUzi5 ... VSNdmm127A
     
  19. helishmeli

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    Never thought of a strobe, sounds pretty cool though I'll have to check it out.

    So long range fpv is not popular in the UK then, eh? That really would be a bummer for me, one of the things that sold me on getting into quads was long range stuff. An by long range, I mean relative to that of multirotors. Fixed wings take long range to a while new level at 3+ hours of flight.
     
  20. helishmeli

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    Ohhh, I literally jut learned about this last night and it scared the **** out of me.

    Thisi whole time I have been descending straight down, I had no idea it could cause VRS. Is this why the max descent is 2 m/s? Could 2 m/s engage a VRS?

    How about manual mode, and those rumors of people using manual mode to descend quickly in an emergency. Since in manual mode the props can spin very slow, could VRS still happen? If the props are spinning super slow it doesn't sound like there is much downwash to catch the phantom.