Signal lost and can't find drone at last seen location

[Hassan Tanveer]

Hey guys - My first post here.

A few days back, I was flying my Mavic Air on the Karakoram Highway and I was doing it from a slow moving bus. After a while, I got lost signals warning on the controller after which I pressed the RTH button so it could fly back to the place I flew it from. It never came back. Also, I went to the last seen location as per the flight log and searched it for two days. There are no poles, trees where it should have landed/crashed/hovered over. I tried reaching out to DJI support and said that they couldn't find anything abnormal with the drone and the flight. They offered me some discount on the purchase as well but I am posting the flight log here to see whether its my fault or whether there was some sort of technical glitch due to which the aircraft became untraceable.

Flight Record link

19-03-24-12-40-50_FLY079.DAT

drive.google.com

I'll really appreciate any help here.

 

[DebianDog]

That sucks... could someone have picked it up and walked away?

 

[Meta4]

I was flying my Mavic Air on the Karakoram Highway and I was doing it from a slow moving bus. After a while, I got lost signals warning on the controller after which I pressed the RTH button so it could fly back to the place I flew it from. It never came back.

After you lose signal, pressing the RTH button won't do anything.
But after losing signal, the drone is programmed to return to the launch point anyway.
The three most likely reasons for it not returning are:

• A sudden loss of power which would cause the drone to fall from the sky
• Obstacles on the RTH path
• Headwinds too strong for the drone to fight

Finding the drone and/or what happened is going to be more complicated because the home point is not where the controller was at the time.
Loss of signal might have been caused by terrain between you and the drone?

The text file from your phone or tablet would be helpful along with an explanation of where you were when signal was lost.
Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it gives you.

 

[sar104]

The home point was properly set at the start of the flight, and the aircraft did enter RTH mode at 309 seconds, just before connection was lost.



The signal loss at the end was a bit abrupt, but there were some dropped data leading up to it so that was possibly just a signal strength problem. It was at 75% battery at that point and winds were less than 5 m/s, so it should have been able to return.

 

[Hassan Tanveer]

That sucks... could someone have picked it up and walked away?

Its a highway, there's no population there. and assuming it reached the home point and was hovering at 30 m, nobody could have picked it up. Even if somebody picked it up and turn it on later, I should have gone a message in the app. no?

 

[Hassan Tanveer]

After you lose signal, pressing the RTH button won't do anything.
But after losing signal, the drone is programmed to return to the launch point anyway.
The three most likely reasons for it not returning are:

• A sudden loss of power which would cause the drone to fall from the sky
• Obstacles on the RTH path
• Headwinds too strong for the drone to fight

Finding the drone and/or what happened is going to be more complicated because the home point is not where the controller was at the time.
Loss of signal might have been caused by terrain between you and the drone?

The text file from your phone or tablet would be helpful along with an explanation of where you were when signal was lost.
Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it gives you.

Here's the text file. Please let me know what you can find.

 

[DebianDog]

if someone turned it back on not in range of the radio. No you would have no idea.

 

[Hassan Tanveer]

The home point was properly set at the start of the flight, and the aircraft did enter RTH mode at 309 seconds, just before connection was lost.

View attachment 69117

The signal loss at the end was a bit abrupt, but there were some dropped data leading up to it so that was possibly just a signal strength problem. It was at 75% battery at that point and winds were less than 5 m/s, so it should have been able to return.

Hey Thanks so much for this image. Not sure how you came up with it but this is exactly what happened. I am wondering why there was a signal problem. The advertised distance is 2+ miles. This was less than a mile. Also, no wind no nothing, then why didn't it return. I checked the starting point and the last seen location. For two good days and I can't seem to find it. Its a massive terrain with plenty of slippery rocks and I fell down a couple of times as well. This doesn't look like Pilot's error or is it?

Also, what happens when a drone is set to RTH and it keeps hovering at a point until its battery runs out? Does it crashes or lands?

 

[Hassan Tanveer]

if someone turned it back on not in range of the radio. No you would have no idea.

Is there a way for us to see if it was turned on again using its serial number or any other identifier?

 

[sar104]

Here's the text file. Please let me know what you can find.

The txt log doesn't show any additional pertinent information. But the flight data do show the launch point to be right in the center of the road. Was there other traffic around? If so, then I suspect that's the answer - someone ran over it and/or picked it up.

 

[Hassan Tanveer]

It was launched from the road yes, middle, not really but we can say that. If the drone did return to the point, it wouldn't have landed there since it was set to hover at 30 m. What happens if you don't go back to the home location and the aircraft keeps on hovering till the battery dies? Does it land at critically low battery or does it crashes once the battery is gone?

 

[sar104]

It was launched from the road yes, middle, not really but we can say that. If the drone did return to the point, it wouldn't have landed there since it was set to hover at 30 m. What happens if you don't go back to the home location and the aircraft keeps on hovering till the battery dies? Does it land at critically low battery or does it crashes once the battery is gone?

You may have misunderstood how this works - you can set the failsafe action (signal lost) to hover or RTH. The aircraft was set to RTH, which results in it returning home and landing, not hovering. Had it been set to hover then it would have hovered until low battery required it to land.

 

[Hassan Tanveer]

And what happens when you haven't set it to land ?

 

[sar104]

And what happens when you haven't set it to land ?

That's not an option under RTH. The options are hover or RTH (which then lands). Yours was set to RTH.

 

[Hassan Tanveer]

Gotcha. For all my previous flights, the aircraft came back to home and kept hovering unless I landed it myself that's why I was assuming it doesn't land on its on after returning to home. So the only option is to look for someone who might have picked it up? no glitches in the flight record that we can see for the aircraft? Sad

 

[Astom22]

Also, the 2+ mile range claim is a best case scenario with no interference whatsoever. I get nervous at about a mile and I only push it out that far on our farm where there isn't another house for a mile in any direction.

 

[MavicFlyer]

Gotcha. For all my previous flights, the aircraft came back to home and kept hovering unless I landed it myself that's why I was assuming it doesn't land on its on after returning to home. So the only option is to look for someone who might have picked it up? no glitches in the flight record that we can see for the aircraft? Sad

If someone -did- pick it up, wouldn't they have to register the S/N with DJI?

If you lose a drone, can you report the drone to DJI and have them flag when someone else tries to register it?

 

[Meta4]

If someone -did- pick it up, wouldn't they have to register the S/N with DJI?

No .. once a drone has been activated, there's no further need to activate it again.
You can buy a secondhand DJI drone and use it without any dealing with DJI.