Disconnected over the ocean! No RTH!

[sptrsn1]

Is there someone that can look at my log file and tell me what the hell just happened to my drone?

Flying along the coast in Maui. It simply disconnected and disappeared over the ocean.
Was only 1700 feet away. clear line of sight, although I was looking into the setting sun, so I couldn't actually see it.

I've seen several posts about these things disconnecting without at least some justification. Is this a known issue?

It's pretty frustrating to just flush a $1,000 down the proverbial salt water toilet.

Thanks for any help.

DJI Flight Log Viewer - PhantomHelp.com

 

[Keule]

It simply disconnected

Do you remember by any chance what the exact message was shwon in the GO4 app?
Was it 'disconnected' or 'Aircraft disconnected'?
Had you connection confirmed at the RC screen?

 

[Lake_Flyer]

You say you couldn't see it because of the sun, but are you sure the RC had a free line of site or could it have been obstructed by those rocks (I can't see how high they are on the map)? That would explain the disconnect. The compass had an error right after take off. That could explain why it didn't return to the homepoint.

Did you do a compass calibration on the take off spot?

 

[Datadogie]

I clicked on street view the rocks don't look that high in that area. So that leaves compass error the likey cause.

 

[macoman]

Is there someone that can look at my log file and tell me what the **** just happened to my drone?

Flying along the coast in Maui. It simply disconnected and disappeared over the ocean.
Was only 1700 feet away. clear line of sight, although I was looking into the setting sun, so I couldn't actually see it.

I've seen several posts about these things disconnecting without at least some justification. Is this a known issue?

It's pretty frustrating to just flush a $1,000 down the proverbial salt water toilet.

Thanks for any help.

DJI Flight Log Viewer - PhantomHelp.com

Your flight looks normal, you decided to go to sport mode at the 6 minutes 14 seconds and at the returns it just stopped recording at the 8 minutes 47 seconds with 60% battery life, 237 feet altitude and 16 satellites. My guess will be that the aircraft hit something. Maybe hit a bird?

 

[Keule]

Maybe hit a bird?

I don't think so - telemetry pitch,roll,yaw did not show any spikes in any direction short before log ends.

The log simply stopped recording, so the app maybe crashed, but the RC was still connected.
Still waiting for the OP to answer my question on that.

 

[MavicCF]

I seem to remember hearing (can't confirm its correct) that the dat. file stored on the device is still being recorded to even if the app crashes, in that case, if you could try to post the dat. it might help some (haven't looked at the log myself yet). Here's the link on how.

 

[sar104]

I seem to remember hearing (can't confirm its correct) that the dat. file stored on the device is still being recorded to even if the app crashes, in that case, if you could try to post the dat. it might help some (haven't looked at the log myself yet). Here's the link on how.

Unfortunately no - the app is recording the DAT file. No app no DAT file.

 

[MavicCF]

Unfortunately no - the app is recording the DAT file. No app no DAT file.

Well so much for that...

 

[MavicCF]

Do you have a video of the flight? I'm curious about the initial compass errors.

 

[Gizmo]

A battery detachment maybe?

 

[sar104]

A battery detachment maybe?

There were some fairly sudden pitch changes at the end of the flight caused by throwing the sticks around in sport mode. That's certainly a possibility.

 

[MavicCF]

There were some fairly sudden pitch changes at the end of the flight caused by throwing the sticks around in sport mode. That's certainly a possibility.

View attachment 35262

I'm still learning about compass errors, so do you think the errors on take off were caused by it being near some kind of metal object on take off and once it was clear of that everything went back to normal? The rest of the flight seems normal and unaffected by it.

 

[sptrsn1]

Disconnected or Aircraft Disconnected. I'm struggling a bit to remember exactly. My wife seems to recall it being two words, but I'm not positive. Probably 'Aircraft Disconnected. But now that I'm thinking about it, I think it simply said 'Connecting', like it was trying to connect. It was giving an audible beep until I pressed the rth button.
The initial compass error was a calibration error which I had to take care of before it could fly. Once I went through the calibration and it showed good. I sent it on top of the car and took off. but yea, I did take off from the car as the ground was rough and sandy lava. I did take off with the 'take off button' and clicked the checkbox to record precise location for return to home.
The rocks are less than 15ft high. I was well high of anything in the area on purpose, plus I was trying to not be obnoxious to other folks.
There was a fair bit of glare looking in the direction of the drone, so I couldn't see it specifically, but I had a clear and unobstructed view of the area. We did not see any birds anywhere in that area. Doesn't mean there wasn't any, but that was actually my first suspicion.
The one thing that I'm still a little confused by.... In looking at the GO4 app right now, it says the RTH alititude is 0. I did not specifically set it before this flight, but had see it before. It also had a max altitude of 0 which clearly was not the case as I was flying at well over 0. Is it possible for those values to be randomly reset and cause a crash?

 

[MavicCF]

Disconnected or Aircraft Disconnected. I'm struggling a bit to remember exactly. My wife seems to recall it being two words, but I'm not positive. Probably 'Aircraft Disconnected. But now that I'm thinking about it, I think it simply said 'Connecting', like it was trying to connect. It was giving an audible beep until I pressed the rth button.
The initial compass error was a calibration error which I had to take care of before it could fly. Once I went through the calibration and it showed good. I sent it on top of the car and took off. but yea, I did take off from the car as the ground was rough and sandy lava. I did take off with the 'take off button' and clicked the checkbox to record precise location for return to home.
The rocks are less than 15ft high. I was well high of anything in the area on purpose, plus I was trying to not be obnoxious to other folks.
There was a fair bit of glare looking in the direction of the drone, so I couldn't see it specifically, but I had a clear and unobstructed view of the area. We did not see any birds anywhere in that area. Doesn't mean there wasn't any, but that was actually my first suspicion.
The one thing that I'm still a little confused by.... In looking at the GO4 app right now, it says the RTH alititude is 0. I did not specifically set it before this flight, but had see it before. It also had a max altitude of 0 which clearly was not the case as I was flying at well over 0. Is it possible for those values to be randomly reset and cause a crash?

The GO4 app won't display the setting you have set unless it's connected to your Mavic. It's kind of in "demo mode" when it's not connected.

 

[sptrsn1]

The GO4 app won't display the setting you have set unless it's connected to your Mavic. It's kind of in "demo mode" when it's not connected.

That's good to know. Previous known values were rth 90 and max 400.

 

[joejaxvic123]

I wonder if taking off from on top of the car did something or it got blinded by the sun.

 

[sptrsn1]

I wonder if taking off from on top of the car did something or it got blinded by the sun.

I considered the could be a problem. When I set it on the car it did not complain at all and seemed to operate normally. But I was looking for a complaint taking off from a metal surface.
The drone was on it way back to me at the time of failure, so the sun was at it's back and the camera as facing nearly straight down. I was kind of looking for sharks. La Perouse bay is know to have a pretty good population and there were signs all over that said there were sightings.

 

[sar104]

I'm still learning about compass errors, so do you think the errors on take off were caused by it being near some kind of metal object on take off and once it was clear of that everything went back to normal? The rest of the flight seems normal and unaffected by it.

There is a 17° shift in recorded yaw just before takeoff that does not correspond to any stick inputs causing a temporary compass error. Without seeing the DAT file it's hard to say what happened, but it did not seem to cause any subsequent flight problems.

 

[joejaxvic123]

Sorry for your troubles.