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Weird RTH issue last night. Lesson learned (may help you too)

Discussion in 'Pro/Adv Discussion' started by RyanK, May 20, 2015.

  1. RyanK

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    Ok, so because of all the rebar in my driveway and sidewalk (in front yard), I usually take off from my back yard, but then walk around to my front yard because there are less trees. Now that I have had 10+ flights, I'm letting the battery go a little further. Well I wasn't watching the RTH time left for the battery and right as I'm landing (in the front yard), literally 2 feet off the ground about to touch down, the auto-RTH takes over and up goes the P3. I didn't want it to go back there, so I hit the autoland button. Well that works (after asking, are you sure?), but then it wants to land practically on my roof, so I have to fight it to bring it back to my front yard. Once I do, I bring it down and it touches the ground, but it's as if it really wants to go back to the place where I told it to auto land, and it keeps fighting me. It finally turned over (completely upside down and motors still going), but fortunately was on soft grass, so no damage done (not even to the props), just a few grass stains which were easy to clean off.

    So I guess the lesson is to be sure to watch the RTH time if you aren't going to land where RTH would be and/or hand catch. But this problem could still have happened if I was hand catching and RTH took over before it reached my hand.

    But I would like to know what I could have done to set the P3 down gently and safely after I told it to cancel the RTH and auto land? And why was it fighting me still once I had already touched it down to the ground? I have video of the screen (using Nvidia shield) if anyone would like to see it.
     
  2. Meta4

    Meta4 Moderator
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    [​IMG]
     
  3. louforgiveno

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    Just tap the button or press and hold to cancel rth?
    Thanks
     
  4. Meta4

    Meta4 Moderator
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    My P3 still hasn't arrived so I can't tell you any more than what the manual says.

    Since cancelling RTH and resuming control is an important part of safe flying, I'd recommend trying it out so when you need it, it will be familiar.
     
  5. gfredrone

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    This happened to someone else while flying indoors. The P3 shot up into the ceiling and that was all she wrote. There was another one that shot up into an overhanging tree just as he was about to land. Not good!

    There should be a way to turn this feature off but I don't believe it's possible.
     
  6. gfredrone

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    There are several ways to override though...

    Here is what the manual says Pg 13:
    2015-05-20_19-42-53.jpg
     
  7. F6Rider

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    A low battery RTH can be cancelled simply by pressing the RTH button, a failsafe RTH (critical low battery or LOS) cannot be cancelled and you only have limited control, such as shifting laterally a bit to select a better landing spot. Indoors just set RTH height to 'Zero' and this will have the effect of turning it off. You need to practice this a few times as when it is needed you might not have the time to 'think' about it before you hit that overhead obstruction. Your best defense is to just keep aware of your battery condition at all times, I look at mine every few seconds.
     
    Meta4 likes this.
  8. gfredrone

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    F6, a critical low battery will cause the aircraft to descend where it is at that point. There is no RTH once it's gone critical, it's coming down. However you can maintain altitude briefly by going full up on the throttle while positioning for a landing spot. Critical low battery and Failsafe RTH are two separate events. Failsafe RTH can be canceled once the Tx link is reconnected by pressing the RTH button. See page 14 and be careful not to touch the throttle in Failsafe RTH if you are flying below the highest object in your RTH path.

    2015-05-20_20-38-17.jpg
     
  9. RyanK

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    Thanks for your replies. I believe I did cancel the rth by pressing auto land, but it still had a mind if its own about WHERE to auto land. I could control lateral movements, but even when I got it in place and on the ground, it was as if it didn't like that spot and wanted to go find its own spot.
     
  10. Stan_in_KS

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    You probably cancelled the RTH that was going to the back yard. But pressing AUTO LAND over your roof, may have told it to land where it was when you pushed that button. In your case over the roof of your home. Might be good for some operators to push the AUTO LAND and then try to cancel it and get control of the Phantom and move it to a new location to land. We know RTH can be cancelled, but can AUTO LAND also be cancelled?

    The Altitude of the RTH is a parameter you get to set. I alway think about going high enough to easily clear all obstacles and get it higher so signal strength and my control, return at a farther distance. Every Phantom pilot, especially 2 Vision pilots, knows how dropping down to take a photo or video puts a lot of obstructions in the path of your radio links. Altitude is a friend, you can see the Phantom better, and the radio can link to it when it is higher and line-of-sight to your controller antennas.

    Flying under branches near the end of a battery is a high risk, because a low battery can trigger an automatic RTH while obstructions are overhead, and every P3 pilot knows the new motors climb much faster than the P2 and give you no time to cancel the RTH before prop blades are flying from hitting obstructions overhead.
     
  11. pqdbr

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    Guys my P3A hasn't arrived yet, so my experience is only with the P3V2+ in NAZA mode.

    In NAZA mode on the P3V2+, all I had to do to abort a RTH was flip the right switch from GPS-lock to ATTI-lock; how does this procedure work in the P3 ?

    Also, is there something like a NAZA mode in the P3 ? How do I enable IOC ?
     
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  12. snowghost

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    I did a RTH (with plenty of battery) to bring her back from way out. I canceled by toggling the switch on the left to Atti and back.
     
  13. edonovanl

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    Isn't there an audible low battery alarm on the P3?
     
  14. F6Rider

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    I know this as I to can read the manual, hence the 'lateral shift to pick a landing spot' Anyone who has read the manual knows that a critical low battery results in an immediate landing. I should not have lumped in the Failsafe as that is mainly for LOS, and yes, it can be cancelled.
     
  15. Dadcat

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    That guy must have a really large living room. An RTH less than 20 meters from home point causes the P3 to Auto Land right where it is. It doesn't climb.

    I've tested this. 20.5 meters from home, RTH causes it to climb to the height you set. At 19.5 meters it just lands. The voice in the app even says "Landing".

    Maybe it's possible an RTH initiated by low battery behaves differently, but I doubt it.
     
  16. 4wd

    4wd

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    You can enable IOC with a toggle/slider in the app, but it won't stick until you have a P3 connected (if you try it before delivery).
    It only gives you course lock now, but homelock is planned.
    The lever on top left side of controller will then activate IOC (courselock) in a similar way to the P2 switch and does also give you back control in RTH scenario if briefly switched across.
     
  17. JayB

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    from 30% mine beeps at me constantly with low battery warning, on one occasion it did attempt to go into RTH mode but I just pushed the RTH button to cancel it then resumed normal control.

    I know its tempting to just get out and fly but I would advise to check and understand how all the fail safes work, preferably in a big open space.
     
    Daniel Voyer likes this.
  18. gfredrone

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    I know what you meant. I was just trying to dumb it down for any new flyers who might be confused by the different RTH scenarios, hence posting the manual.
     
    F6Rider likes this.