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Power off free fall?

Discussion in 'General Discussion' started by wkf94025, Mar 23, 2014.

  1. wkf94025

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    I have gone up to 1600 meters on a couple occasions, either to get aerial photos of a large property, or to test FPV range. Once or twice I have realized too late I may not have saved enough battery left to get down. Not smart. Fortunately made it back each time with a bit to spare. I have since read (though not tested) that descending in ATTI is faster and/or less power than descending in GPS. True?

    My real question here is whether one could shut off the motors, free fall for several hundred meters, restart, and use what little battery remains for non-crash landing. I would never try this unless I somehow truly painted myself into the "too high, oh shitake" corner, but I am curious if: (1) anyone has ever powered off in flight, restarted, and lived to tell about it? (2) thought through the theory of such a risky free fall / restart maneuver?

    A pilot buddy yesterday observed that the Phantom couldn't auto-rotate down. I am fairly certain he is right, and imagine that a powerless Phantom would fall rather quickly and without grace. Thoughts?
     
  2. LandYachtMedia

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    You for sure don't want to do a free fall on purpose. Not unless you have a parachute system.

    Your friend is correct that the Phantom will not autorotate. It will auto-tumble. :?
     
  3. Shrimpfarmer

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    Its an interesting question and for anyone who has a Phantom thats no longer required it would be a good test for the community. Assuming its at a considerable altitude then maybe there would be enough time to recover. The only thing I am not sure off is will it restart its motors in freefall ? Also if its tumbling then the g-force caused by righting itself could possibly rip the blades off ?

    Certainly not a technique to be used other than in dire emergencies. Imagine the props running out of power and shutting down themselves at height. You have nothing to lose letting it fall and giving the battery a few secs to recover and then restarting I suppose.
     
  4. ElGuano

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    Yes, this can be done, but not really consistently. Search on YouTube, there are people who do this. It seems the chances of being able to regain attitude while in free fall with a Naza is about 75%. Not terribly good odds. One guy built a quad that falls flat (like a flying squirrel) specifically to do this maneuver.

    Edit: here's a great example: http://youtu.be/nA8_6Oa3_3c
     
  5. EMCSQUAR

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    I love the "victory loop"
     
  6. ianwood

    ianwood Taco Wrangler
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    Manual mode is a good way to get down quickly:

    [youtube]http://www.youtube.com/watch?v=83fraTicuUk[/youtube]
     
  7. Lee C

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    I kind of treat my flying like my scuba diving.

    I fly the long high bits first then bring it in closer to finish off the battery.
     
  8. LandYachtMedia

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    That is an excellent flight plan in my opinion.