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What happens if you cut the engines mid air, can you turn them back on and save the P3

Discussion in 'Pro/Adv Discussion' started by adjmirealty, Jul 14, 2015.

  1. adjmirealty

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    Not that I would ever do this but im curious to find out what would happen in the case of a fault where you cut the engines out, can you turn the engines back on while it's falling through the air and give full throttle up? will the P3 correct and save it self, do to the GPS leveling out the P3... I've seen a video on YouTube of a guy pulling the drone 3-5 feet away while its hover and let go and the P3 would return to its original place.. As well as him holding it on an extreme angle while its hovering and letting go the same thing happened it would return... Will this acti in the same way if the motors are cut off and turned on? But mainly will the P3 have the ability to turn on and have enough power w the controller using the throttle to simply get it back into its hover state..
     
  2. SitkaGrover

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    There was a guy on here that posted he tried this because he saw a video of someone doing it. Needless to say, he crashed his drone. I do not believe that the necessary flight dynamics will be met while the quad is falling and flipping around for it to "right itself" and maintain flight.
     
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  3. ScottyT

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    I've heard a few stories of people doing it, but none verifiable.

    I'd soooooo love to try it one day from a decent height. While recording it from multiple angles, of course. One day.
     
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  4. SitkaGrover

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    I am in the same boat, the pure desire to really see this work is pretty high for me too. Not $1000 high yet, but high lol.
     
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  5. ScottyT

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    Perhaps we should start a gofundme for a trial phantom or two :)
     
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  6. SitkaGrover

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    Compared to some of the other crowdsourcing campaigns I have seen, "Potato Salad"(which I funded haha), I don't think that is such a horrible idea!
     
  7. Meta4

    Meta4 Moderator
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    Maybe.
    The P2 could do this trick (at least sometimes) if it had enough air below and there have been a number of youtube videos of this happening.
    So far I've only heard of one attempt with the P3 and it didn't work.
    It's unknown if this was because the P3 couldn't manage it or if the pilot was a dill.
    If you have an Apple device, give it a go in the simulator or if you're really curious you could try for real and report back.
    Needless to say, it is a risky exercise and not recommended.
     
  8. adjmirealty

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    The simulator dosnt act as the drone would act all it does is fly straight down and when you turn the engines on it just falls to grass with it on simulator needs improvement it should work with diff setting you choose its best to learn how to menuver it quickly
     
  9. sergekouper

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    I believe that after a few seconds, let's say 5 sec of free fall before you restart the engines, it will be too late for the GPS mode to rebalance and stop it falling before it hits the ground...
    This table doesn't take account of the resistance of the air but gives an idea i think.
    free fall.png
     

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  10. 2k3sgm

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    I tried this with the simulator. I kept raising the altitude 50 feet until I got to a height I could cut the motors and restart. It was 750'. I would never try this with the actual P3 but it was something I had to do with the sim. And as adjmirealty stated the sim doesn't truly represent the real life actions of the P3.
     
  11. tvckz

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    It will fall down for sure - do not experiment
     
  12. IdahoCopterHawk

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    You will need a really big foam field, about 6' feet deep...
     
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  13. Meta4

    Meta4 Moderator
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    Air resistance has a significant impact on a falling Phantom with the shape and the propellers providing drag.
    It doesn't continue to accelerate but reaches a terminal velocity that varies between 28-35 mph.
    GPS shouldn't have much to do with it as the GPS is only used to provide horizontal position.
     
  14. BigKenny

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    If you are mid flight and hold the sticks in the lower right/lower left positions, will the motors cut out mid flight? I have been paranoid I might accidentally do this and was curious what would happen??

    Thanks!
     
  15. Meta4

    Meta4 Moderator
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    Kenny .. read this from the manual - especially the last bit I highlighted in pink
    [​IMG]
    No need to be paranoid. You would have to be flying like a crazy chimp to CSC mid-flight. And if you fly like that you're not far from crashing anyway.
    It's not something that happens in normal flight.
     
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  16. ctp

    ctp

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    Yes! A CSC will happen any time you give the command, regardless of where the P3 is physically at. The CSC is a safety feature. There's not much point discussing the merits, DJI has decided the CSC is necessary and we are stuck with it.

    CSC will be initiated by bringing both sticks down and to any of the four bottom corners at the same time: bottom inside, bottom outside, bottom left, bottom right. This is clear covered in the manual.

    The Restart Test:

    This sounds like a perfect candidate for someone with a broken camera removed and willing to sacrifice what's left of the P3. Guessing that the height required will be more than anyone normally flies at and the pratical result is no one will be able to use this to save a P3 after an unintentional CSC.
     
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  17. Dronebow

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    How about a gofundme for everyone and we can all use the funds to buy more stuff. Hey, this concept is what the Greeks have been using for years.. ;-)
     
  18. 30secs

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    God I do Not like CSC. I am often near the CSC position and it's stupid that it's that easy to do and destroy your phantom with a tilt of a stick.

    Here's an idea: switch to f mode THEN csc works. Why not do that Dji??!?
     
  19. Monte55

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    I actually like CSC. BUT I've have heard cases where someone was flying backwards in front of a boat recording and with full back right stick and left or right input, low throttle, and yawing at the same time, they entered CSC and shut down motors. I think if
    they placed the bird in front of the boat flying facing them...reset course lock and use it....flying forward would have right stick forward. No way to enter CSC then.
     
  20. jlo

    jlo

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    That guy was telling tales. Claimed P3 crashed from over 1000 feet and only damage was the camera fell off....oh, yeah, it landed in some tall grass so no damage. :rolleyes: