Lost connection and crashed

[Waliaf]

Hi all

I was flying in a all city in Denmark, the connection was perfect, distance was in cos and I was not flying very high. At certain moment I got the error connection lost, and I saw then the M2P just going down it was crazy, the aircraft crashed 60 meters from me, lucky there was no one on street. The front sensors are damaged, I cannot fly.

I have fresh care but the aircraft is also not very old. What should I do?

 

[runeOfRune]

If you have care refresh just send it, other than that, you can post the .DAT log and we can maybe see what happened.

How to retrieve a V3.DAT from the tablet

 

[Housenotes]

I am really getting tired of seeing these type of posts with lost connection on a Mavic 2 pro. I’ve had mine two weeks when the controller quit working. Would not allow the aircraft to go up. ended up having to send the controller back to DJI. Their shipping label that I used took five days to get the drone to them, another week for them to acknowledge they received it, three more days to check it out and repair it, and it’s going to take another five days to get it back. So I will have owned it for five weeks when I get it back and I’ve only been able to use it for the first two. Now I’m worried that even using it after the repair that I’m going to lose control and crash/lose it because of a disconnection/lost signal like everyone else. I may have to look into returning this and buying a different product. NOT HAPPY!

 

[Thomas B]

Hi all

I was flying in a all city in Denmark, the connection was perfect, distance was in cos and I was not flying very high. At certain moment I got the error connection lost, and I saw then the M2P just going down it was crazy, the aircraft crashed 60 meters from me, lucky there was no one on street. The front sensors are damaged, I cannot fly.

I have fresh care but the aircraft is also not very old. What should I do?

Use the DJICare, it will pay for itself and you’ll have all problems fixed, not just the ones You can see.

 

[AMann]

I am really getting tired of seeing these type of posts with lost connection on a Mavic 2 pro. I’ve had mine two weeks when the controller quit working. Would not allow the aircraft to go up. ended up having to send the controller back to DJI. Their shipping label that I used took five days to get the drone to them, another week for them to acknowledge they received it, three more days to check it out and repair it, and it’s going to take another five days to get it back. So I will have owned it for five weeks when I get it back and I’ve only been able to use it for the first two. Now I’m worried that even using it after the repair that I’m going to lose control and crash/lose it because of a disconnection/lost signal like everyone else. I may have to look into returning this and buying a different product. NOT HAPPY!

Sorry for your issue with it, they don’t usually have problems, you are seeing only messages from those that do.

 

[RayOZ]

Send it back to DJI. If it was a fault with the drone, DJI would repair/replace it without charge. If it's pilot error, then use the Care Refresh to replace it.

 

[Meta4]

I am really getting tired of seeing these type of posts with lost connection on a Mavic 2 pro. ...
Now I’m worried that even using it after the repair that I’m going to lose control and crash/lose it because of a disconnection/lost signal like everyone else.

Losing connection DOES NOT cause the drone to crash.
Page 17 of your manual explains what does happen if the connection is lost:
Failsafe RTH automatically activates after the remote control signal is lost for more than two seconds.

You are reading reports from confused people.
The loss of connection they report is what shows on their phone/tablet after the problem that's caused their drone to suffer a total loss of power.
That could be a loose battery or a serious hardware or programming issue, but it is nothing to do with losing connection.

 

[Waliaf]

Losing connection DOES NOT cause the drone to crash.
Page 17 of your manual explains what does happen if the connection is lost:
Failsafe RTH automatically activates after the remote control signal is lost for more than two seconds.

You are reading reports from confused people.
The loss of connection they report is what shows on their phone/tablet after the problem that's caused their drone to suffer a total loss of power.
That could be a loose battery or a serious hardware or programming issue, but it is nothing to do with losing connection.

Agree, lesson learned, I must read the user manual better.

However 30 minutes before the crash I had the low battery warring and the aircraft was returning home without any issues. Then I changed the batteries. The first 10 minutes flight was successful, but then I got the lost connection. In this case the aircraft either should have come back to the home point or hover. But in my situation (as I was flying in vos) I saw the aircraft flying away and making strange movement and I saw it went down, I could not do anything to avoid it. I was luck: there was no one on the street, secondly I was able to find the aircraft easily.

There was no wind , and it was just few minutes after the sunset.

So the question is , if the connection was lost why the aircraft did not return home or not hover until the connection is back?

 

[Waliaf]

If you have care refresh just send it, other than that, you can post the .DAT log and we can maybe see what happened.

How to retrieve a V3.DAT from the tablet

Thanks , I will post the data log for sure , I am very curious to see what happened, why the aircraft did not returned to home or did not hover until the connection was back. What happened was that connection was lost and after few seconds the aircraft start moving and crashed :/

 

[Waliaf]

I am really getting tired of seeing these type of posts with lost connection on a Mavic 2 pro. I’ve had mine two weeks when the controller quit working. Would not allow the aircraft to go up. ended up having to send the controller back to DJI. Their shipping label that I used took five days to get the drone to them, another week for them to acknowledge they received it, three more days to check it out and repair it, and it’s going to take another five days to get it back. So I will have owned it for five weeks when I get it back and I’ve only been able to use it for the first two. Now I’m worried that even using it after the repair that I’m going to lose control and crash/lose it because of a disconnection/lost signal like everyone else. I may have to look into returning this and buying a different product. NOT HAPPY!

Agree, I. Not worried that much about M2P, it can either be repaired or replaced but DJI or I can purchase a new one. Bit It is scarry , what will happened if someone was on the street and I could have caused serious injuries? This is something that DJI need to look at, as there are more and more these cases. I have learned my lesson I will not fly in the cities any more, but you never know...

 

[Meta4]

The first 10 minutes flight was successful, but then I got the lost connection. In this case the aircraft either should have come back to the home point or hover. But in my situation (as I was flying in vos) I saw the aircraft flying away and making strange movement and I saw it went down, I could not do anything to avoid it. I was luck: there was no one on the street, secondly I was able to find the aircraft easily.

There was no wind , and it was just few minutes after the sunset.

So the question is , if the connection was lost why the aircraft did not return home or not hover until the connection is back?

The description of your incident is confusing.
Did the drone fly off somewhere and crash into an obstacle, or did it just stop flying and fall from the sky?

If it lost signal while still powered, it could only have continued flying for three seconds before RTH would initiate.

I suspect that it just stopped flying because either the battery was dislodged or the drone just shut down.
If that's the case, you would have found it close to the last point in the recorded flight data.
And if so, the disconnected message was because the drone had lost power.
That would also explain why it did not come back.

More information is required to be able to be certain of any more.

 

[Saigondroner]

Thanks , I will post the data log for sure , I am very curious to see what happened, why the aircraft did not returned to home or did not hover until the connection was back. What happened was that connection was lost and after few seconds the aircraft start moving and crashed :/

I have not seen your log, but you mentioned you were flying at sunset, and not a high altitude. Satellite visibility in Denmark, at that hour, could have contributed to the accident.

Copenhagen is not full of skyscrapers, but I have had very bad satellite coverage in your region. (Sweden).

Something to consider....

Cheers

 

[Saigondroner]

I am really getting tired of seeing these type of posts with lost connection on a Mavic 2 pro. I’ve had mine two weeks when the controller quit working. Would not allow the aircraft to go up. ended up having to send the controller back to DJI. Their shipping label that I used took five days to get the drone to them, another week for them to acknowledge they received it, three more days to check it out and repair it, and it’s going to take another five days to get it back. So I will have owned it for five weeks when I get it back and I’ve only been able to use it for the first two. Now I’m worried that even using it after the repair that I’m going to lose control and crash/lose it because of a disconnection/lost signal like everyone else. I may have to look into returning this and buying a different product. NOT HAPPY!

I am as well. I kept my new M2P grounded because of the SC mess regarding 3rd party app integration. I’m in no hurry to watch it fly off into the breeze. I have an original P3 if I want to see that. . I really regret selling my Mavic Platinum. It was solid.

Time will tell

 

[Meta4]

you mentioned you were flying at sunset, and not a high altitude. Satellite visibility in Denmark, at that hour, could have contributed to the accident.

How do you figure that?
GPS sat reception is the same at any hour.
The sun goes down in the evening, but the satellites just keep orbiting.

 

[globetrotterdrone]

A lot of (unnecessary) speculation here ...
Provide the DAT-file for the experts here or keep sending it in to DJI please.
Otherwise you and we won't know.

Hope you get it fixed soon.

 

[Saigondroner]

How do you figure that?
GPS sat reception is the same at any hour.
The sun goes down in the evening, but the satellites just keep orbiting.

No, they are not. They are mid orbit, not normal geostationary. Depending on the time of day, one receives a different set of satellites, because they orbit differently than those aligned with earth’s orbit.

Also, cloud cover and (not joking) solar flares can affect entire GPS constellation’s receivability.

All of this orbital complexity, and your high northern exposure, can drastically affect mid flight GPS satellite numbers.

GPS.gov: Space Segment

Information about the space segment of the Global Positioning System (GPS)

www.gps.gov

Glonass, and EU’s Galileo constellations behave similarly.

Best

 

[Saigondroner]

A lot of (unnecessary) speculation here ...
Provide the DAT-file for the experts here or keep sending it in to DJI please.
Otherwise you and we won't know.

Hope you get it fixed soon.

Yup....I’ve flown all over the world, and some areas are well known for their atmospheric interference, during some seasons.

 

[Meta4]

No, they are not. They are mid orbit, not normal geostationary. Depending on the time of day, one receives a different set of satellites, because they orbit differently than those aligned with earth’s orbit.

It's hard to tell what you are saying here but the idea that GPS doesn't work well at night in Copenhagen is ridiculous.
Have a look at this to see what effect time of day has on satellite visibility for Copenhagen:

Visibility

Also, cloud cover

Cloud cover affecting GPS ??
Now you really are joking.
The whole point of GPS is to provide an all-weather navigation system.
One that only works in clear weather and in daylight wouldn't be much use.

 

[Saigondroner]

It's hard to tell what you are saying here but the idea that GPS doesn't work well at night in Copenhagen is ridiculous.
Have a look at this to see what effect time of day has on satellite visibility for Copenhagen:

Visibility

[QUOTE="Saigondroner, post: 765592, member: 97871"Also, cloud cover

Cloud cover affecting GPS ??
Now you really are joking.
The whole point of GPS is to provide an all-weather navigation system.
One that only works in clear weather and in daylight wouldn't be much use.[/QUOTE]

Yes, you’re right. That is why there are many satellites in various positions, to overcome these phenomena, and ensure solid location information.

Ever had your TV blank out during heavy rain or snow? The same thing happens to GPS, but having 24 of them moving around ensures you should receive 8-12 reliably.

I suggest you download UAV Forecast, and check local conditions, and how many satellites are predicted to be seen at different hours of the day.

Please don’t infer I am suggesting pilot error, or I’m joking. Here is the UAV forecast at this moment. I am an old satellite engineer...quite helpful to know IMHO.

 

[Meta4]

Ever had your TV blank out during heavy rain or snow?

Yes ... but I've never seen GPS drop out because of weather.
GPS frequencies are well away from TV frequencies and much less subject to attenuation because of rain.

I suggest you download UAV Forecast, and check local conditions, and how many satellites are predicted to be seen at different hours of the day.

So you didn't see the link I included above?

Visibility

It shows that Copenhagen doesn't lose navigation sats after dark.