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Uncommanded Slow Descent at 35% Battery

Discussion in 'Phantom 2 Vision + Discussion' started by srandall25, Oct 12, 2014.

  1. srandall25

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    3 times in the last two days, my phantom just started descending while about 20' high and 30' away from me until finally crashing to the ground. Each time I had over 30% battery, greater than 8 satellites, hardly no wind, good battery on controller, no battery alarms, no control signal loss message, nothing... I tried full throttle up and it just wouldn't respond. Any idea what this could be?
     
  2. Dirty Bird

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    What firmware are you running Scott?
     
  3. djczing

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    Ive had incidents of this the last few times out.

    I think they are VRS stalls, induced, perhaps, by a weak left/front motor.

    Yesterday the left front wouldnt start up with the others, or had a hard time starting up. I dindt feel any more resistance than in the others, and strangely, no more heat after flight than the others.

    In any case, I had /2/ VRS encounters yesterday, from about the height you mention. On the first one, I crammed the throttle up, the bird bounced and kept flying.

    On the second one, it bounced and... took the camera/gimbal halfway off, flipped over on its back and twitched.
    I put it all back together last night, and blew out the motors, paying extra attention to the port-front. Now they all start up strong. I think I cured the port-front, and hopefully the ease at which Ive been getting into VRS lately.

    The flight videos of the bounces dont show me doing anything radical, except maybe a /little/ too agressive on the throttle-down. In the past, the phantom would tell me when I was about to 'ring' as it would start to wobble. I could react to that. In these VRSs, I was already slow and stable, inch forward and down, and bang. straight to the ground I went.

    I hope it was the motor had some junk in it. I hope the easy VRS is a thing of the past.
     
  4. djczing

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    By the way - ths is bringing light too all of the 'my bird just fell outa the sky' reports on the board. It would seem to make sense that a slow-to-respond motor could induce a yaw and help the VRS situation develop quickly.

    I dunno.
     
  5. srandall25

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    the latest... 3.2 i believe...
     
  6. flyNfrank

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    You don't happen to have the Vision+PU app or Flytrex Core2 or Flytrex Live Tracker, do you? If so there is a good chance either flight logger may show what is going on.

    Btw, it's possible that even though you were unable to get the quad to increase altitude, you should be able to hold that lever up and it will maintain altitude so you can land it yourself.
     
  7. sbarton

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    I had this happen to me too recently. So weird. I was flying FPV at about 100' and returning to me at about 35% battery, when I noticed I was about 40' up yet did not try to descend the bird. I gave it full throttle up, but it continued to come down and landed kinda hard. Nothing broke other than scrapped props lukily. So weird.

    -Scott
     
  8. singapore_phantom

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    Would be great if you guys could post your clips of these drops, so we can check if perhaps there's a pattern in the flight manoeuvres that precede the drop.

    I had something similar happen the other day. I took a pretty sharp turn at a decent clip, was about 10 feet up when props just seemed to lose traction. I corrected quite aggressively (up stick) after sensing the copter wasn't responding initially and after a second or so the props clawed their way back. By then, the copter was barely a foot away from the ground. I reviewed the clip later and you can see that the manoeuvre just before it happened is nothing out of the ordinary. I'll look up the clip and post it.