I have a Q regarding flying above 400ft AGL around the structure, when using your phantom 4 does the Dji appknow that you are the base of a communications tower thus allowing you to flying above 400ft as per part 107?

If not then how the heck do you circumvent this in order to flying 400 ft above the tip of that tower?

I am possibly not understanding your question, but why should the App know that you are at the base of a structure? As long as you stay within the Phantom's altitude limit which is 1640 feet AGL, you can fly 400 ft over any structure that is not more than 1240 feet tall... You just have to set the Max altitude in the App. Bear in mind that altitudes are measured from the takeoff point ...

Antonio76 Posted at 2018-7-10 00:45
I am possibly not understanding your question, but why should the App know that you are at the base of a structure? As long as you stay within the Phantom's altitude limit which is 1640 feet AGL, you can fly 400 ft over any structure that is not more than 1240 feet tall... You just have to set the Max altitude in the App. Bear in mind that altitudes are measured from the takeoff point ...

Thank you for clarifying that, so the app is what has the limiter.

Aloha snowy,

     Well, Antonio got to you first!  His answer is correct.  The FAA has a loose interpretation of what a structure is.  A structure can be a tall tree like a sequoia, a building, an antennae tower like your problem or in my case a cliff face on a mountain.  As Antonio says, all altitude calculations are from your take-off point.  That is why the DJI voice says your launch point has been recorded.

     The DJI GO 4 app has no idea what your altitude is, it is just recorded as 0.  The MAX Altitude the DJI app allows is 500 meters or 1640 feet as noted by Antonio.  If you set your Max Altitude at 500 meters, you will enable this option.  In my case, I live above a jungle marsh 30 feet downhill.  When I fly down there, my altitude is recorded in negative numbers.  When I fly way up to the highest point on the ridge of the cliff face (called Pali in Hawai'ian), I can go up to 1640 feet.  Bummer, the clifftop is higher.

     So, if you launch from the parking lot near the tower and the tower will not interfere with your communications with your P4 Pro, if you have set your MAX Altitude to 1640 feet (500 meters), you will be able to fly up past the 1000 foot tower and go 400 more feet.  If you try to fly 640 feet past the top of the tower to the MAX Altitude DJI allows, you will then be in violation of Part 107 by 240 feet.

     You will also be able to fly 400 feet away from the tower at the top.  However, you still are responsible for avoiding any manned aircraft operating in the area.  In my case, tour helicopters like to fly close to the Pali for their passengers, so I have had to learn how to dodge and hide behind the ridges when I hear them.  That kind of adds some adventure to the flight.

     Hope this helps!

Aloha and Drone On!

One other thing - be wary of Class E airspace.  Re Cetacean's latter example, if you're anywhere near a medium sized airport, check the sectional chart and be sure Class E controlled airspace doesn't start at 700 feet.  Obviously, you can't enter that without FAA authorization.  It may start at 1200 feet too, depending on the airport and your proximity to it.  Airmap won't help you because it assumes you're dutifully flying at 400 feet max.  The sectional will tell you what's going on.  

http://www.boldmethod.com/learn-to-fly/airspace/class-e/

Ahh the sectional charts has it listed as class E  also have MOA within boundaries, I was actually curious about the whole thing
since I was watching a vide on youtube where a fella went over the comms tower. Love this forum it's active and everyone has been so helpful.

Hello there. I appreciate your time bringing this query to us. In regards with the distance, it will be based on the connection between aircraft and remote controller. About the altitude, it will be based how high your drone is from the ground.

Mark The Droner Posted at 2018-7-10 02:10
One other thing - be wary of Class E airspace.  Re Cetacean's latter example, if you're anywhere near a medium sized airport, check the sectional chart and be sure Class E controlled airspace doesn't start at 700 feet.  Obviously, you can't enter that without FAA authorization.  It may start at 1200 feet too, depending on the airport and your proximity to it.  Airmap won't help you because it assumes you're dutifully flying at 400 feet max.  The sectional will tell you what's going on.  

http://www.boldmethod.com/learn-to-fly/airspace/class-e/

Mark, your message can be interpreted in various ways, some of which are correct and some of which are not.  Unfortunately, there's a lot of blatantly wrong information on this topic out there, including much from  forums and fly-by-night online drone "universities" and similar sites.

The key question that many budding and certified drone pilots cant seem to get their head around is this one:

"Is ATC authorization required to operate a drone under Part 107 in all controlled airspace in the USA?"

The answer to this question is NO, it is NOT.

The relevant regulation is from AC 107-2 5.8:

"Though many sUAS operations will occur in uncontrolled airspace, there are some that
may need to operate in controlled airspace. Operations in Class B, Class C, or Class D
airspace, or within the lateral boundaries of the surface area of Class E airspace
designated for an airport, are not allowed unless that person has prior authorization from
air traffic control (ATC)."

So, clearly operation in all of the above listed pieces of controlled airspace requires ATC authorization.  But this is NOT the full extent of controlled airspace in the USA.

Specifically, there are (at least) two cases that fall outside the above:

- Class E airspace to the surface which has NOT been designated for an airport (but instead has been designated for an airspace extension)*
- There is no ATC authorization to fly in class E controlled airspace not associated with an airport, as long as all other regulations are met.  For example, if a 400 foot tower exists in airspace that is class G to 700' AGL and then class E 700 AGL and above, operations above the tower IN CLASS E (CONTROLLED) AIRSPACE are permitted without further ATC authorization at, for example, 750 feet AGL.

That said, 107-2 also states:

"Those planning sUAS operations in controlled airspace are encouraged to contact the FAA as
early as possible"

If you plan to fly in ANY controlled airspace, regardless of ATC authorization required, you are "encouraged" to contact the FAA anyway.  

As 107-2 is written and as quoted above, especially with the second example, it is clear that it is not the case that ATC authorization is "always" required for controlled airspace.  Unfortunately, FAA documents themselves are often ambiguous and contradictory, especially when the FAA makes "quick reference guides" and such a lot of the nuance, but the above from 107-2 is pretty definitive.

** PLUG:  if anybody out there is interested in a reasonably priced drone test prep from actual aviation professionals rather than the latest fly-by-night expensive online drone 'school', please give Dauntless Aviation's groundschool apps a look. This particular question is dealt in more detail there along with several illustrated examples.  we routinely get feedback from users who have been misled by other preps who are great at marketing but not so good at the content.  we have over 5000 actual and representative FAA UAS questions with full explanations.  While of course we make errors too sometimes, the difference between our stuff and that made by others is pretty clear. **.




* there is slight ambiguity in the reg with regard to this, but this interpretation seems to be most correct.  people can legitimately disagree on this and a definitive FAA ruling / legal letter would be good.    It is worth noting that a LOT of the drone regs are quite poorly written and have ambiguity.

Good stuff for sure.   Words like "recommended" and "encouraged" should not be used in federal regulations.  Regulations should be cut and dried, black and white.  No doubt there was some sense of urgency in getting these regs published hence the ambiguity.  The question I have is; why would you need to fly 400' above a 1200' tower?