Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

400 ft altitude .. and topography?

Discussion in 'Pro/Adv Discussion' started by Digdat0, Apr 11, 2016.

  1. Digdat0

    Joined:
    Feb 20, 2016
    Messages:
    870
    Likes Received:
    375
    Location:
    Oregon, USA
    (its a slow day at work)

    I'm pretty sure the answer is no, but does the max altitude limit/law allow ANY wiggle room for topographic elevation increases above ground level? Can I fly higher as the elevation of a hill increases, to greater than 400 feet?

    Take the image below, can I fly my desired path to the red X? Is there any possible way, legally, to do this? (Outside of in a real helicopter)

    [​IMG]
     
  2. alokbhargava

    Joined:
    Sep 28, 2015
    Messages:
    5,119
    Likes Received:
    1,652
    Location:
    San Francisco, CA
    Very good way of presenting your question. Technically the answer is no, you should not cross 400' above your home point. Even if you go up from a while and then go down, you will be out of site and will have a solid obstruction on your way. So question is can you reach the third hill at all? or signal block will stop you there it self.
     
    #2 alokbhargava, Apr 11, 2016
    Last edited: Apr 11, 2016
  3. flpholt

    Joined:
    Jan 27, 2016
    Messages:
    4,178
    Likes Received:
    1,561
    Location:
    palm harbor florida
    400 feet isn't a law it is just a suggestion from faa
     
    Discoverydave and Tony Cowan like this.
  4. Ghost Rider

    Joined:
    Apr 5, 2016
    Messages:
    319
    Likes Received:
    87
    Exactly. The FAA can blow me.
     
    Tony Cowan, Apilot101 and flpholt like this.
  5. OnnoJ

    Joined:
    Mar 8, 2016
    Messages:
    5
    Likes Received:
    1
    Location:
    Norfolk VA, USA
    Just take off from any of the summits...
     
  6. flpholt

    Joined:
    Jan 27, 2016
    Messages:
    4,178
    Likes Received:
    1,561
    Location:
    palm harbor florida
    just fly that route not likely your going to encounter any aircraft
     
  7. Meta4

    Meta4 Moderator
    Staff Member

    Joined:
    Jan 8, 2014
    Messages:
    7,729
    Likes Received:
    3,450
    It looks like the forum is a good place to get bad information.
    The answer is YES .. of course
    The magic 400 feet is 400 feet above the ground.
    It's not 400 feet above launch point, 400 ft above sea level or 400 ft above anywhere else.
    It's 400 feet above the ground that is directly below your Phantom.
     
  8. Ghost Rider

    Joined:
    Apr 5, 2016
    Messages:
    319
    Likes Received:
    87
    Have you ever seen a forum without bad information?

    I don't fly over 400 feet because I don't have a need. When that need arises, the FAA can kiss my ***. If a plane is flying at 500 feet around my house, the last thing that dude is worried about is hitting my drone. He's going down.
     
    Richard Gozinya and joe21 like this.
  9. Duncan Campney

    Joined:
    Feb 14, 2016
    Messages:
    49
    Likes Received:
    22
    Location:
    Great Falls, VA
    DJI Go uses 400 ft from your take-off point, but that's due to it's limitations. It doesn't have a way to measure the distance to ground beyond the ~5 meters that the ultrasonic sensor can read, so it doesn't KNOW how far you are off the ground.

    The FAA limit is 400 feet above ground level. So yes, you can fly up to 400 feet above the highest mountain peak in your illustration, assuming you can maintain visual contact with your craft.

    I'd like to know the precise way the 400 ft AGL rule is interpreted though. If you reach a sheer 500 ft cliff then you have to climb to >500 feet at current ground level in order to go above the cliff. Presumably that is allowed, but I wonder what the specific rules are, or if they are even defined?
     
  10. tcope

    Joined:
    Jan 29, 2015
    Messages:
    3,516
    Likes Received:
    1,387
    Location:
    Salt Lake City, UT
    It's 400 above ground level. AGL is the height above the ground directly under the drone.
     
    bradbrok likes this.
  11. Ghost Rider

    Joined:
    Apr 5, 2016
    Messages:
    319
    Likes Received:
    87
    I say, be smart. Know your surroundings and do what you need to do.
     
    RCFantom and Apilot101 like this.
  12. Mark The Droner

    Joined:
    Aug 26, 2015
    Messages:
    3,970
    Likes Received:
    1,160
    Location:
    Brookeville, MD, USA
    This question comes up at least a couple times a week, but you did the best job of describing your question of any I've seen. Well done, sir.
     
    Excavator99 and Digdat0 like this.
  13. Meta4

    Meta4 Moderator
    Staff Member

    Joined:
    Jan 8, 2014
    Messages:
    7,729
    Likes Received:
    3,450
    I think that FAA rules don't specify any details for flying drones in that particular scenario but here are the relevant rules for real planes:
    § 135.203 VFR: Minimum altitudes.
    Except when necessary for takeoff and landing, no person may operate under VFR

    (a) An airplane—

    (1) During the day, below 500 feet above the surface or less than 500 feet horizontally from any obstacle; or

    (2) At night, at an altitude less than 1,000 feet above the highest obstacle within a horizontal distance of 5 miles from the course intended to be flown or, in designated mountainous terrain, less than 2,000 feet above the highest obstacle within a horizontal distance of 5 miles from the course intended to be flown; or

    (b) A helicopter over a congested area at an altitude less than 300 feet above the surface.

    Note that planes have to maintain a horizontal separation distance from the obstacle, not just height above the ground.
    So you should not encounter much air traffic flying near a cliff face.
    You also won't find any FAA inspector with a long ladder and a tape measure to check.
    General aviation aircraft don't have a radar or laser altimeter to give them accurate heights above terrain either.
    A Cessna pilot has to calculate just as a Phantom pilot does.
     
  14. joe21

    Joined:
    Oct 20, 2015
    Messages:
    169
    Likes Received:
    124
    Location:
    USA
    DJI doesn't limit your altitude as far as I can tell. I have flown at more than 400 ft above my home point several times. No warnings, no limitations imposed by the software. There may be user settings to limit altitude, but those are easily changed. I fly in an area with elevation changes of >400 ft. If DJI limited me to 400ft above home point, my bird would have hit a tree long ago while flying at "400ft" (according to the software).
     
  15. SGs

    SGs

    Joined:
    Mar 16, 2016
    Messages:
    72
    Likes Received:
    25
    Location:
    Seattle
    Dunno where you live but I routinely see planes in my area around 1000' AGL. Yesterday alone I saw 1 at 500' doing turn around a point then two more in tandem doing gods knows what at 500' maybe a touch higher. Point is lots of air traffic can be at or below 1000'. Can you live with the after math if that 1 in 100,000 scenario happens.

    That being said as long as your somewhere between 400' and 0' AGL you should be okay nearly all the time. I'd be more worried about signal loss or something.
     
  16. alokbhargava

    Joined:
    Sep 28, 2015
    Messages:
    5,119
    Likes Received:
    1,652
    Location:
    San Francisco, CA
    Check the flying path OP has described with home point at the lowest level. It's a puzzle to every one.
     
  17. Meta4

    Meta4 Moderator
    Staff Member

    Joined:
    Jan 8, 2014
    Messages:
    7,729
    Likes Received:
    3,450
    There's no puzzle ...it's very straightforward.
    There is no point where his Phantom would be more than 400 feet above ground level.
     
  18. Ghost Rider

    Joined:
    Apr 5, 2016
    Messages:
    319
    Likes Received:
    87
    I live in Atlanta. Right under where planes circle to setup for long final. They fly at about 4,000 feet. FedEx MD-11s seem to fly lower for some reason. Like I said, be smart and know your surroundings.

    Not going to argue whether a P3 would bring down an airliner. I'll leave that to those who don't understand airliners.
     
  19. Digdat0

    Joined:
    Feb 20, 2016
    Messages:
    870
    Likes Received:
    375
    Location:
    Oregon, USA
    Thanks. And I used PowerPoint for my visual .. :)

    Thank you. This is what i was thinking, but thought it would be a good question to ask others as well. cheers.
     
  20. Tony Cowan

    Joined:
    Jan 8, 2016
    Messages:
    1,115
    Likes Received:
    283
    Here in the U.S I will obey 400 for the most part. But now always. The Max is 1640 agl. Really only worried about small aircraft. Helicopters etc. know area. Do homework in case you just go high. Testing for me was one thing doing it regularly. Nah. I don't want my video or photo to look like a Google map image. No thanks.


    Sent from my iPhone using PhantomPilots mobile app