Hi all

Yesterday I had my first scary situation because I lost control about my drone and RTH lead the drone above water. Luckilly I could grap the drone out of mid air (already one leg in the water) before it flew further away from the shore and so nothing bad happened.
Quiet some things went wrong during that flight and also a couple of things happened which I don't understand. Here is the story:
Yesterday I was out riding my bike over the Gotthard pass where I wanted to take some pictures near a pretty small lake.
I parked on a public car park near that lake and prepared for take off right next to the car park.
The drone was in good shape, batteries fully charged. Weather was good, sunshine with a little breeze. No people around.
So I took off and let the drone hover for a couple of seconds (~15 sec) to double check everything was fine.
I flew a couple meters and suddenly I got an alarm which stated that I am flying in a restricted area. I didn't understand that message because I was sure that I was outside of any airport airspace and I couldn't see anything special on the DJI map. I cleared the alarm and tried to continue flying but as soon as I tried to move the drone it stopped and the alarm appeared again. A second check on the DJI map revealed a blue area next to me. It was weird, next to us was a tunnel entrance to some kind of bunker muesem. Why the hell should this ever be geofenced?! But yeah, I was sure that area had to be problem. In the meantime the drone hovered slowly towards the lake and I started getting nervous.
Because I couldn't control the drone manually anymore I thought return to home will bring it back to where it took off. I was clearly standing outside the geofenced area and I thought it will fly back to me and land. As soon as return to home procedure started, the drone detected some obstacles on it's way and and flew backwards in the complete wrong direction and above the water. I cancelled the rth quickly and tried to fly manually but it still didn't work because of the restricted area alarm. The only thing I could control was the height, I could go up and down, nothing else. So I decided to jump in the water and grab the drone out of the air as long as it is near the shore. No experiments.

I was 100% sure there was no blue, geofenced area on the map at the moment I took of. I can't explain to myself what went wrong. I am also quite sure the app showed "all green" (radio connection, gps, battery) before take off because that's what I always look for.

So here are my questions:
- I always expected that take off is refused when you are in a restricted zone. But it obviously worked!? Is there any kind of delay between powering on the drone and "loading" the restricted airspaces?
- Looking at the picture below, I was clearly outside the restricted area, why do I get an alarm when I am outside? Are there any kinds of "security-distances"??
- In such a situation, why can I only fly up and down when I am in a restricted zone?! I clearly intended leave that area but I couldn't. Has a blue, geofenced area a ceiling altitude which I could have passed? Could I somehow navigate the drone with waypoints which are clearly outside the restricted area to make it leave?
- What is RTH supposed to do when the drone is near a restricted area? It somehow flew backwards and then tried to land in the water...?!

best regards

Upload your flight log to PhantomHelp using these instructions and post a link to the uploaded log in this thread.

In the meantime, I can make a couple of comments regarding your post. First, the specific action the drone will / should take depends upon the specific type of geofenced area it's in or near. Second, with regard to your comment about there being no zone where you were standing, the relevant location is where the drone happens to be flying and not where you're standing when you control it. Upload the log and it's very likely that someone can help you better understand exactly what happened.

Gimpy Posted at 7-23 08:59
Upload your flight log to PhantomHelp using these instructions and post a link to the uploaded log in this thread.

In the meantime, I can make a couple of comments regarding your post. First, the specific action the drone will / should take depends upon the specific type of geofenced area it's in or near. Second, with regard to your comment about there being no zone where you were standing, the relevant location is where the drone happens to be flying and not where you're standing when you control it. Upload the log and it's very likely that someone can help you better understand exactly what happened.

Of course the relevant location regarding a no zone is where the drone is flying. Looking at the flight path, it was always outside.

Sounds scary ... I have been at Gotthard Pass right it was opened after the winter but I was flying at the other side of the lake because there were still up to 10m snow. Got the same warning as you about a restricted zone nearby but flying was smooth and uncomplicated (despite the amount of power lines there). I could imagine that they (the military?) have some electronic equipment running near the cave so maybe this jams the remote control and / or GPS on a drone?
Glad to hear you could capture the drone manually!
Will be interesting to see your flight logs.

Here are the flight logs: https://www.phantomhelp.com/LogViewer/72QJ4VY42DJ83LIVOA7N/

Yep it is some military zone. Underneath public area. I could cry....


Copy paste from https://www.dji.com/ch/flysafe/geo-map  :
"Authorization Zones. In these Zones, which appear blue in the DJI GO map, users will be prompted with a warning and flight is limited by default. Authorization Zones may be unlocked by authorized users using a DJI verified account."

I'm still 100% sure I could not see this blue area at take off! That's really annoying, because form now on I can't trust what is shown on that DJI map because it could change during flight....

gravity981 Posted at 7-23 09:05
Of course the relevant location regarding a no zone is where the drone is flying. Looking at the flight path, it was always outside.

I was referring to this part of the post where the wording implied you thought it would return to you because you were outside a geofenced area.

"I was clearly standing outside the geofenced area and I thought it will fly back to me and land."

Anyway, it looks like you've now figured out what happened on your own.

Somehow the link in my post is only text. Second try.
Here are the flight logs: https://www.phantomhelp.com/LogViewer/72QJ4VY42DJ83LIVOA7N/

gravity981 Posted at 7-23 09:33
Somehow the link in my post is only text. Second try.
Here are the flight logs: https://www.phantomhelp.com/LogViewer/72QJ4VY42DJ83LIVOA7N/

Apart from keeping away from NFZ it had no effect on your flight, in your second RTÉ you were further than 20 meters and less than 2000 meters so Rth route will first be to follow its outward route for 1/2 minutes before flying directly home, if you didn’t know it would look like it’s flying away from you you then panic and cancel.
I’m not sure what kind of nfz you were in the worst NFZ the worst thing that can happen to you is aircraft will be forced landed .

gravity981 Posted at 7-23 09:33
Somehow the link in my post is only text. Second try.
Here are the flight logs: https://www.phantomhelp.com/LogViewer/72QJ4VY42DJ83LIVOA7N/

Double post .....

Gimpy Posted at 7-23 09:24
I was referring to this part of the post where the wording implied you thought it would return to you because you were outside a geofenced area.

"I was clearly standing outside the geofenced area and I thought it will fly back to me and land."

Ehm, no. I didn't figure it out. The flight log viewer is nice. But the only thing I learned is that the drone goes crazy near blue areas and I will triple check the map the next time before take off.

I would like to know if there would have been a way to land the drone safely without getting my feet wet. Is there a way to fly away from a restricted area or is the only option to go down?

hallmark007 Posted at 7-23 09:58
Apart from keeping away from NFZ it had no effect on your flight, in your second RTH you were further than 20 meters and less than 2000 meters so Rth route will first be to follow its outward route for 1/2 minutes before flying directly home, if you didn’t know it would look like it’s flying away from you you then panic and cancel.
I’m not sure what kind of nfz you were in the worst NFZ the worst thing that can happen to you is aircraft will be forced landed .

Thank you for the reply. Can you elaborate on RTH? Is there detailled manual I can read about RTH procedure? Especially the part with the outward route for 1/2 min? I didn't know about it.

Probably gonna play around with RTH on a plain field...

the maps are not accurate. maybe fly further away from nfz next time.

gravity981 Posted at 7-23 10:10
Thank you for the reply. Can you elaborate on RTH? Is there detailled manual I can read about RTH procedure? Especially the part with the outward route for 1/2 min? I didn't know about it.

Probably gonna play around with RTH on a plain field...

Hi gravity, I was looking at the wrong log, having looked at your log again I realized that you were within 20 metres of homepoint, in this situation if craft is below 2 metres it will ascend to 2 metres and fly home, if it’s above 2 metres it will fly home at that height, when it went into RTH mode I suspect it didn’t move very far probably because of obstacles I’m not sure if you were in trees or rocks , maybe you can tell us a little more about terrain.
I’ll leave one page of RTH there are 6 in your manual you should be aware of .

Yeah next time I'll stay away from nfz... or at least I'll not fly near an nfz and near a lake at the same time...

I was reading a little bit about RTH here: https://store.dji.com/guides/how-to-use-the-djis-return-to-home/
"If your drone is less then 20 meters away when you press the RTH button then it will land just where it is." "However, if the landing zone is hazardous then it will try to find somewhere safe to land"

Looking at the flight log, I'm sure that's what happened in my case.
The second part is really vague. Something which probably is not going to work.

The last thing that bothers me now is that the app did not inform me about the nfz BEFORE take off ... So many safety features which make the whole flying more unsafe... pfff

Btw, there's a way to unlock flying in blue "authorization zones" on a preannounced date. It seems the only thing you have to provide is your flight controller's serial number.

hallmark007 Posted at 7-23 11:11
Hi gravity, I was looking at the wrong log, having looked at your log again I realized that you were within 20 metres of homepoint, in this situation if craft is below 2 metres it will ascend to 2 metres and fly home, if it’s above 2 metres it will fly home at that height, when it went into RTH mode I suspect it didn’t move very far probably because of obstacles I’m not sure if you were in trees or rocks , maybe you can tell us a little more about terrain.
I’ll leave one page of RTH there are 6 in your manual you should be aware of .

There were some rocks and it was pretty steep terrain (~5m) from the car parking down to the water.

Because "RTH current altitude option" was disabled (and still is) and I was in between 5m and 20m of the home point the aircarft lands immediately after initiating RTH. (Page 18 in the manual)
And because it detected some obstacles on the ground it flew backwards direction lake.
Stupid concatenation of problems....

What a nightmare flight, hopefully you made it through safely ^^