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Flying near bridges, not a good idea?

Discussion in 'General Discussion' started by almustafa, Jan 25, 2016.

  1. almustafa

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    I was thinking about flying my P3P under a bridge. The bridge is a massive steel structure that would be about 40' above my P3. I only have about 30 flights under my belt and all flown in wide open spaces. Is it possible that my P3 could loose its gps bearing while under the bridge and at the same time lose contact with the RC because of interference. In that case it would attempt to land from where it lost contact, straight down to the river flowing under the bridge. Would experienced flyers skip this flight as too risky?
     
  2. Meta4

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    If you are about 40 feet away from the steelwork you would probably be safe from compass errors.
    If the Phantom started to slowly spiral and have difficulty flying straight, back off further away.
    If you fly under the bridge deck, the width of the bridge and distance from it will affect how much of the sky it blocks out and what that does to your satellite lock.
    You might get away without sat loss for a narrow bridge if you weren't too close or you might lose sats.
    You'd have to be ready for that.
    As long as you have a clear unobstructed line of sight to the Phantom you should not lose control signal.
    Another thing to consider is the possible effect of RTH height if you were under the bridge.
     
  3. Helijoc

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    Go fly in ATTI for practice first if you are worried about interference. Would encourage everyone to practice in this mode so you can handle loss of compass/GPS. We are spoiled when everything is good.
     
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  4. Frankc

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    I can see where your coming from. I shall have to practice that at sometime. However the 'training wheels' are still on for me. Got to get used to all the different modes or feel 100% orientated with the controls so it feels natural before I go to that step. Still getting used to left is right etc when the heli is flying back towards me.
     
  5. happydays

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    How wide is the structure? If it's only a few feet, then at full beans you'll be through it before you know it. It can be nerve wracking though. What I'd do is to take a practise run, making sure the heading is correct and that you're in the centre of the span, then back off, swallow hard and give it full beans forward. When you have cleared the bridge, throttle up to clear the height of the structure and regain signal.
     
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  6. Frankc

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    Nit picking, as we say in the uk, if he has lost signal how can the throttle up and clear the structure and regain signal? But I do agree with what your saying. The forward momentum should enable him to clear the bridge and if he does loose signal the heli should go into RTH and gain height. At which point he should recover the signal and control. Personally I think it will be fine. Perhaps the compass may get messed up for a few seconds but should recover once clear of the steel. :)
     
  7. happydays

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    He won't lose control signal - not with lightbridge. Maybe FPV. And the craft will have to receive no control signal for a full three seconds before RTH would kick in. The GPS might lose signal for a very short period, but if he's on full gas then he'll recover it again quite quickly and so it shouldn't be an option. I haven't done any steel bridges, but I have been under a stone railway viaduct before. No issues.
     
  8. Darmie

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    I would fly in atti mode and with the momentum would push you through if anything may have happened, but again, Not sure If I'd fly under a bridge.
     
  9. Buckaye

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    If you aren't comfortable with ATTI - I wouldn't fly under a bridge... being comfortable with ATTI is the only thing that will save you if actually do lose GPS in that situation. I would get more comfortable with the bird before trying a possibly tricky maneuver like that. Just my 2 cents.
     
  10. oakmeadows

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    I have the Dji f450 and it's no problem but I wouldn't take a chance with my p3p


    Sent from my iPad using PhantomPilots mobile app
     
  11. PJ Orlando

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    daveleeds likes this.
  12. WetDog

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    There are movies of guys doing bridge inspections with Inspires. The get within about 10 feet of the bridge for long periods of time. That said, I'd agree with being comfortable with atti mode. You need a to do that at some point anyway.

    Also consider walking under the bridge with the Phantom with the system on to see if you lose signal. That obviously depends on your ability to access the area. Apps like Autopilot and Letchi would also allow you to do this.

    Finally, bridges are considered critical infrastructure and the paranoids might come after you. After all, you could be a terrorist.
     
  13. almustafa

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    Thanks for the advise and cautions. I think I will put this mission on hold for now, until flying under all modes becomes second nature for me.