Maybe a silly question about restricted airspace.

[hank970]

I was in western Colorado, driving north on an unpaved road in the Book Cliffs leading toward Baxter Pass. I'd just left Mesa County and entered Garfield County. My intent was to capture some still photos of the local topography in furtherance of my photography hobby. I am strictly a recreational flyer.

It's a pretty remote area, and the road is not maintained by the county. The only signs of development in the immediate vicinity were some aerial transmission lines paralleling the right-of-way, a couple of seemingly derelict corrals, and a gas compressor facility. There are no military or other sensitive sites in the area.

A cold front was approaching, and partly cloudy skies had given way to a general overcast and plummeting temperatures. Not a great day for photography. Even so, I pulled onto a dirt track a mile or so beyond the compressor station and made preparations to launch my Air 3. I was in a narrow valley, and the surrounding terrain was several hundreds of feet higher all around. When I powered up the drone and controller, a warning message immediately popped up on the controller screen. The gist of the message was that I was in a restricted airspace, that I was not to exceed 500 AGL flight (100 feet higher than is permissible), and that any operation of the drone could result in a loss of control (I regret not having taken a picture of the screen and don't recall the exact wording).

Restricted area? I was probably 20 or 25 miles from the Grand Junction Regional Airport and more than 10 miles from the nearest private airstrip on Mack Mesa. I heard no aircraft and received no ADS-B warning.

When I returned home, I consulted my Denver Sectional map. There was no indication on the map of restricted airspace in the area where I had stopped. I noted, however, that the location where I chose to fly lay under the direct airway between the Grand Junction VOR/DME and the Vernal, UT airport (the latter is a supposition, because I don't have the adjoining Salt Lake City Sectional, but it's the nearest town in that general direction with an airport). Direct airways are denoted on the map by straight, light blue lines connecting navigation aids. The Grand Junction VOR/DME is not located at the airport but is situated instead on the uplands in Glade Park, CO, about 16 miles west.

And so, after this lengthy narrative, a couple of questions: 1) Are direct airways, by definition, restricted airspace? 2) Was this warning typical of something I might expect from DJI's geofencing function?

I can find no mention of such restricted status in any of my reference materials, including the "Pilot's Handbook of Aeronautical Knowledge," online, or on the Sectional map's legend.

 

[GFields]

All airspace, including Class G has a altitude limit for drones of 400' AGL So, regardless of the message that is the highest you're allowed to fly anyway (legally)

 

[Vic Moss]

Sectionals are basically useless for drone info. They just aren't detailed enough, nor do that have UAS specific restrictions. Use the FAA's UAS Data Map (ArcGIS Web Application).

A quick look at both the FAA map and the DJI map show nothing in the area. It may be one of the smaller DJI zones in that area, but nothing that would make you lose control.

 

[hank970]

Sectionals are basically useless for drone info. They just aren't detailed enough, nor do that have UAS specific restrictions. Use the FAA's UAS Data Map (ArcGIS Web Application).

A quick look at both the FAA map and the DJI map show nothing in the area. It may be one of the smaller DJI zones in that area, but nothing that would make you lose control.

Vic;

Thanks for the info and for steering me to the FAA's UAS Data Map and the ArcGIS site. I wasn't aware of that resource. Neither was I aware of the Demaree Canyon Wilderness Study Area in the location where I had intended to fly. There were no signs posted along the roadway. As a retired national park ranger, I know that, for administrative purposes, the National Park Service accords potential wilderness the same legal protections as designated wilderness. The Bureau of Land Management administers the Demaree Canyon holding. If it adheres to the same policy as the NPS, then that might explain why the message popped up on my screen. The restriction would probably be built into DJI's geofencing database.

Does geofencing actually try to prevent a drone from intruding into a protected airspace or merely warn against entry? And if a drone does enter such a zone, does that result in loss of control? I seem to recall reading of instances in these pages where operators blundered into restricted zones and then had trouble getting their drones to fly back out of them.

 

[MARK (LI)]

Do you have Air Control or Aloft on your phone?...if there are any restrictions, you do get a short explanation

 

[Vic Moss]

Vic;

Thanks for the info and for steering me to the FAA's UAS Data Map and the ArcGIS site. I wasn't aware of that resource. Neither was I aware of the Demaree Canyon Wilderness Study Area in the location where I had intended to fly. There were no signs posted along the roadway. As a retired national park ranger, I know that, for administrative purposes, the National Park Service accords potential wilderness the same legal protections as designated wilderness. The Bureau of Land Management administers the Demaree Canyon holding. If it adheres to the same policy as the NPS, then that might explain why the message popped up on my screen. The restriction would probably be built into DJI's geofencing database.

BLM usually doesn't have the same restrictions as NPS properties. Also, the Wilderness designation is for land use. We can fly over it if we follow FAA regs and don't harass wildlife. But just because we can, doesn't mean we should. NPS it tough to get permission to fly at. I flew for the new Mesa Verde visitor video, and that was a complete pain to get permission. And it was FOR the NPS. But I digress...

Also, if you look at the DJI GEO Map, it won't stop you from flying into those areas. Restricted areas are red with a dark red outline. See the AFA areas below. There are none in the GJ area.

Does geofencing actually try to prevent a drone from intruding into a protected airspace or merely warn against entry? And if a drone does enter such a zone, does that result in loss of control? I seem to recall reading of instances in these pages where operators blundered into restricted zones and then had trouble getting their drones to fly back out of them.

GEO Fencing can stop you, but only for restricted airspace. For instance I was flying near the Air Force Academy, and flew up to their GEO Fence. It stopped me at the border like an invisible fence. I could go up, down, left, and right, bot not forward. I was doing it all legally of course, I just wanted to see how accurate the DJI GEO Fence was. I can honestly tell you that it's pretty darn accurate.

I haven't seen any documented cases of people flying into a GEO Fenced area and not being able to fly back out of it. About the only way I can see that happening is if they took off and didn't get GPS set. Once the entered that area and GPS GEO Zone kicked in, it may not let them fly out again. Or at all.

 

[hank970]

Thanks fo

BLM usually doesn't have the same restrictions as NPS properties. Also, the Wilderness designation is for land use. We can fly over it if we follow FAA regs and don't harass wildlife. But just because we can, doesn't mean we should. NPS it tough to get permission to fly at. I flew for the new Mesa Verde visitor video, and that was a complete pain to get permission. And it was FOR the NPS. But I digress...

Also, if you look at the DJI GEO Map, it won't stop you from flying into those areas. Restricted areas are red with a dark red outline. See the AFA areas below. There are none in the GJ area.

GEO Fencing can stop you, but only for restricted airspace. For instance I was flying near the Air Force Academy, and flew up to their GEO Fence. It stopped me at the border like an invisible fence. I could go up, down, left, and right, bot not forward. I was doing it all legally of course, I just wanted to see how accurate the DJI GEO Fence was. I can honestly tell you that it's pretty darn accurate.

I haven't seen any documented cases of people flying into a GEO Fenced area and not being able to fly back out of it. About the only way I can see that happening is if they took off and didn't get GPS set. Once the entered that area and GPS GEO Zone kicked in, it may not let them fly out again. Or at all.

Thanks for the clarifications.

 

[Zbip57]

The gist of the message was that I was in a restricted airspace, that I was not to exceed 500 AGL flight (100 feet higher than is permissible), and that any operation of the drone could result in a loss of control (I regret not having taken a picture of the screen and don't recall the exact wording).

DJI's geo restrictions may or may not have anything to do with whether it's actually legal or illegal to fly there. It's DJI's approximation of what they consider "safe".

However, their geofencing system very much can interfere with your plans if you're trying to takeoff or fly into one their fenced off areas. Always check DJI's online map to ensure you're clear to go. Select United States and your DJI model: fly-safe.dji.com/nfz/nfz-query

If you were heading up the road to Baxter Pass, red-X on the left side of this map, you were probably still under that grey circle covering Grand Junction.



The different coloured DJI Geo-Zones increase in severity from orange, blue, to red. The grey fan-shaped extensions off the end of runways, and the large grey circle, are "Altitude Zones".

DJI prevents you from flying into Altitude Zones at heights higher than those indicated. The big circle shows the restriction starts at 500m (that's 1,640ft)! No idea why they feel that's necessary. BTW, that 1,640ft height is measured relative to your take off altitude.

A better example is clicking on the fan-shaped runway extensions at Grand Junction. Close in the Altitude Zone starts at a height of 60m (197ft), and further out it's 150m (492ft). You can fly lower than that under those zones, but DJI will stop your drone from climbing higher than those limits.

The warning message you received is to make you aware that such a ceiling exists above you. You're not prevented from taking off, and you can fly higher than that anywhere outside of those zones. But, when flying higher, your drone will be prevented from entering or crossing those altitude restricted zones.

For example, if your RTH height is configured higher than the altitude zone restriction, your drone may bump into that invisible wall or ceiling and be prevented from returning home.

 

[hank970]

Thanks. That's a very cogent and helpful response.

I've flown at multiple locations within the area encompassed by the large grey circle surrounding the Grand Junction airport (but never so close to its outer margins) and have never before received such a warning message on the controller. The maximum operating altitude I set for my Air 3 is 390 feet relative to launch elevation, and I've never flown higher than that. A voice-prompt in the controller alerts me when I reach that altitude, and the drone refuses to go higher. An altitude of 500 meters would be off the charts.

After viewing the fly-safe map, I'm curious why one of the fan-shaped zones emanating from the GJ airport is oriented east-west. The airport does not have, nor has it ever had, an east-west runway. The other fans do conform to the orientation of the airport's runways.

 

[Zbip57]

The airport does not have, nor has it ever had, an east-west runway.

Well spotted. Bizarre, huh?

It must be a hellishly difficult job to maintain such a geo-fencing database covering the entire Earth. It's another good example of how you should never count on it to be a trustworthy reference of where it's legal or not to fly.

Just because DJI allows you, or not, to fly in certain spots doesn't mean it's safe or legal do so. But, it's still important to always check their geo-zone map before heading out to fly somewhere new. It may actually be perfectly legal to fly there, but it sucks to discover only after you arrive that DJI prevents your drone from launching there.

There is a process to obtain a prior unlock code from DJI, if you can satisfactorily demonstrate that you are authorized to fly there.

There is a link, right below the geozone map, to "Report Incorrect Data". Maybe DJI will reward you with a special cookie if you let them know their map is wrong.