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Flying over cliff

Discussion in 'General Discussion' started by PerthPilot, Apr 20, 2016.

  1. PerthPilot

    PerthPilot Guest

    Q: What happens if you take off on top of a cliff and then fly over the cliff which has an 800ft drop.....take into account that your max altitude is set to 400ft????
     
  2. The Editor

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    Nothing (other than you are now breaking the law since your agl height is now twice the legal limit).
     
  3. PerthPilot

    PerthPilot Guest

    Are you 100% sure nothing will happen? and how can I be breaking the law when my max attitude is set to 400ft?
     
  4. The Editor

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    Yes, I'm 100% sure and its not altitude (which is measured from sea level) but height above ground level (agl).
    The legal limit (for Aus) is 400ft agl. The Inspire doesnt have a clue on altitude since it gets its reference height data from the internal barometer which is zero'd at take off/switch on.
    Even if you are 2,000 feet up a mountain, the Inspire will take its take off position as 'zero'

    Since you are only legally allowed 400ft agl, if you fly off the edge of a 800ft cliff you are then 800ft agl and thus breaking the law.

    Yes - I'm sure. This has been covered numerous times on the forum
     
    Trevlan likes this.
  5. PerthPilot

    PerthPilot Guest

    Ok cheers for that
     
  6. Skynet1

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    While technically you would be in violation of the maximum permitted altitude regulation for the reason mentioned, I'm thinking so long as you don't fly out away from the side of mountain cliff you had been perched on to any great distance so as to interfere with aircraft and the like, your UAV shouldn't really present a safety hazard or concern to others, depending on your location of course.
    The regulations were obviously put into place for the safety of all concerned, manned aircraft, and civilians alike, and the chance any such aircraft would be flying very close to any such mountain side, or cliff would be slim to none, unless as result of an aircraft malfunction, pilot error, or otherwise were to occur of course, in that case you would have a much larger issue to contend with than that of violating any such UAV altitude regulations, IMHO. : )
     
    #6 Skynet1, Apr 20, 2016
    Last edited: Apr 20, 2016
  7. InspiredOne

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    Am I missing something...? o_O

    Sample.jpg
     
  8. PerthPilot

    PerthPilot Guest

    Yes....didn't you see that girl in the red bikini?
     
  9. ChadAustin

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    I have flown off a mountain for a documentary- and while I'm aware it is technically breaking the law (the mountain is 1200 ft above the valley), it was a risk I was willing to take due to the following precautions:

    1. I called the nearest airport and informed them I was flying, what it was for, and what did their traffic look like that day. It was a small local airport, about 4 or so miles away. They weren't expecting any, but I gave them my cell and told them to call me if anything changed.
    2. I only flew out from the summit a few hundred feet, and maybe a 100 ft up.
    3. I had a spotter with me, checking the sky, as a back-up.
    4. I just flew for a few minutes, long enough to get my shot at least 3 times.

    I have a lot of friends in law enforcement who say, "It's ok to go over the speed limit a little... just don't do it excessively, hope you don't get caught, but if you do, you were still speeding."
     
  10. licensed pilot

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    Nothing, the UAV only "knows" its altitude over take off point, derived from the internal barometer. No radar altimeter in Inspires, yet.
     
  11. Pottertown

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  12. licensed pilot

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    "This aircraft is 800 feet above sea level." Only if you are flying at the sea shore. Bringing sea level into this confuses the issue. The regulation addresses height above the ground only, not sea level. Pilots call it MSL and it's only relevant so every aircraft has a common reference point. Otherwise, good diagram.
     
  13. InspiredOne

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    Okay, so using Pottertown's diagram, assume the drone was flying a straight course at point "2" in the diagram. He is, technically, flying at 400 AGL and maintaining that status. However, a full-sized aircraft--a Cessna Skyhawk--is flying at an altitude of 800 feet at a 45 degree angle and heading toward point "2". Both the drone and the Skyhawk hit point "2" at the same time and they collide.

    The drone was flying legally. The Syhawk was flying legally. How does this go down (pun intended)? Lawyers on each side would have a hay-day with a scenario like this.

    See what I'm getting at here?
     
  14. AllanM

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    Surely that's all pedantic.
    The drone may have been flying legally up until the time it endangered the Cessna. At that point it was flying illegally...?
     
  15. Eduardo

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    Right, at that point both would be 400 ft AGL.

    If the Cessna is allowed to fly at that height, it would be the same as both flying over a flat surface and maintaining 400 ft AGL.
     
  16. InspiredOne

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    No, the Cessna's altimeter will show 800 feet (presuming it was zeroed prior to take-off). Full-sized aircraft's altitude is measure by atmospheric pressure.
     
  17. InspiredOne

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    You're making the assumption that all aircraft/drone collisions will always be the drone's fault.
     
  18. Eduardo

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    Ok, the Cessna takes off and goes to 800 ft altitude (from take off point, which is sea level. In that case, AGL = ASL).

    But as it moves towards the mountain, the terrain starts to go up, the Cessna altimeter keeps showing 800 ft, but it's height to the ground gets lower according to the mountain slope (it may even go to zero and crash to the mountain, altimeter still showing 800 ft).

    At least that's what I got from that drawing posted earlier.
     
  19. The Editor

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    OK chaps, I think there is a bit of confusion here......

    Somehow this thread has turned into a 'Mountain' thread instead of a 'Cliff' thread.
    The OP question was what happens if he flies over the edge of an 800' cliff. Cliffs (in my world) a pretty vertical in nature and hence my answer that you would be illegal almost immediately since as soon as you flew over the (vertical) cliff it would put your aircraft over 800' above the ground below.
    However...... Flying up or down a mountain or incline is a completely different kettle of fish and different arguments/rules/legality would apply.

    Hope that clears things up.
     
  20. AllanM

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    Yes, I believe it is up to the drone pilot to avoid endangering [manned] aircraft. Which in reality means staying out of their way.