Mavic disconnected, no RTH & is lost

[modbuilder]

Haven't seen any discussion of this possibility, but I know that there are (illegal) phone signal jammers that can be purchased on-line. I guess they're intended to jam any data signal in the 2.4GHz band. I get reminded of these gadgets every time I'm in a restaurant and some inconsiderate a-hole is holding a loud conversation on his phone.

Can't help but wonder if someone on one of the sailboats felt intruded upon by the drone. But then you don't know if a jammed signal would be treated as a lost connection and initiate the RHT. Also don't know the effective range of those gadgets, but just wanted to throw in an idea that hasn't been discussed. The OP's experience is troubling. Best suggestion I've read is the battery disconnect. I know that can occur, and battery securement is part of my pre-light check.

 

[sar104]

Haven't seen any discussion of this possibility, but I know that there are (illegal) phone signal jammers that can be purchased on-line. I guess they're intended to jam any data signal in the 2.4GHz band. I get reminded of these gadgets every time I'm in a restaurant and some inconsiderate a-hole is holding a loud conversation on his phone.

Can't help but wonder if someone on one of the sailboats felt intruded upon by the drone. But then you don't know if a jammed signal would be treated as a lost connection and initiate the RHT. Also don't know the effective range of those gadgets, but just wanted to throw in an idea that hasn't been discussed. The OP's experience is troubling. Best suggestion I've read is the battery disconnect. I know that can occur, and battery securement is part of my pre-light check.

That kind of jamming is functionally identical to interference. It doesn't carry any executable instructions and so it is going to result in the same outcome - failsafe RTH.

 

[meens]

That kind of jamming is functionally identical to interference. It doesn't carry any executable instructions and so it is going to result in the same outcome - failsafe RTH.

Speaking of the boats, I suppose they belong to a sailing club of some sort. Did you go there to interview people, maybe the are some witnesses who can tell if they saw your drone and what happened when you lost connection

 

[ScubaBob]

I fly my Mavic Pro regularly, usually over my house capturing the sunset view I keep the firmware updated and it has been behaving normally.

But on Dec 30h the Mavic Pro suddenly disconnected & is now lost.
I was flying at a distance of 750m and was 50m high, above water - filming some yachts.
I was shooting video at the time, I had 17 satellites and 70% battery, no warnigns of any kind.
Suddenly all signal disconnected - no video, no control.

When I took off from a beach it registered the RTH location, and RTH was set to fly home at min imum height of 30m
and there were no obstacles between me & the last location of the drone.

At first I waited for the drone to RTH, and reconnect. Nothing happened.
I pushed the RTH button on the controller, it beeped but nothing else happened.
I then waited for the drone to RTH when its battery got to 30%. Nothing happened.

So my Mavic Pro disappeared, and is presumably at the bottom of the harbour.

I retrieved all data from the app including video, flight data etc
It shows what I explain above - drone is working normally,
battery has a linear decrease from 100% to 70% at point of disconnect.
17 satellites, no warnings during the flight at all.

But at the point of disconnect all data ends, and the final GPS position
is in the middle of the harbour, where the cached video ended.

Why no RTH?
Was there a power loss? If so, how?
The flight records show the battery had a linear decline from 100% to 70%
There was no low power warning. Why would the drone suddenly lose all power?
The video shows i did not hit anything. How could there be an instant 100% power loss?

Or did its firmware crash?
How could it suddenly stop functioning?


I'd appreciate any suggestions or advice.

I contacted DJI support, sent them all the data and their response was:
there is no record of a failure, and "we could not verify what happened afterwards."
so they offered me 30% discount on a replacement Mavic Pro.

But here is the thing: my Mavic is only 8months old, so still under warranty.
The flight data shows I was using the drone under completely normal circumstances,
and yet they will not honour their own warranty.

"For your claimed case CAS-1366163-J5Q3N7, we have already finished the analysis, and the result is as follows:
1. The aircraft worked in GPS mode and responsed to the pilot's command well;
2. At T=09:15, H=52 m, D=753.5 m, the pilot pushed forward the Elevator stick and moved the Rudder stick leftwards, then the record ended;
3. The home point: -41.1121000 174.8527440, the last point: -41.1183687 174.8493132.

With the record ended without any sign of abnormality, we could not verify what happened afterwards."

This is really sad that they don't support this. If they can't show error on the user then you only have two alternatives: defect in the product or adverse Divine Intervention. I will bet on the defect.

 

[sar104]

This is really sad that they don't support this. If they can't show error on the user then you only have two alternatives: defect in the product or adverse Divine Intervention. I will bet on the defect.

That's a bit of an oversimplification. For example, an improperly latched battery would be user error, and at least as likely as a product defect, based on past accidents examined on these forums. Hence their usual offer of 30% discount.

 

[Mac]

This is Sad, Might be lost contact in the Board or battery latch lifted. many possible scenarios.

 

[dennyc39]

Sorta acted like a sudden and total electrical failure of some kind. I have trouble thinking of anything else that would cause a sudden loss of all communication with no warning, together with failure of the RTH function which should have run autonomously if the drone continued operating after the loss of communication. I believe this also would leave no traces on the flight log.

Interference or signal failure might have showed some warning, and not prevented RTH.
Sudden control or airframe problems like a prop coming off would show on the video.

 

[RAM]

Hi
This happened to me too
Three minutes into flight full battery on mavic and remote full satellite RTH recorded reception around 700 meters mavic just disappeared
DJI said they do not know what happened offered 30 % joff just for the mavic .
very disappointing.

 

[sar104]

Hi
This happened to me too
Three minutes into flight full battery on mavic and remote full satellite RTH recorded reception around 700 meters mavic just disappeared
DJI said they do not know what happened offered 30 % joff just for the mavic .
very disappointing.

Did you recover the Mavic?

 

[BerndM]

What are all those numerous "Downlink restored" notations in your log. It seems like the was some sort of a connectivity issue starting at 9 seconds

 

[sar104]

What are all those numerous "Downlink restored" notations in your log. It seems like the was some sort of a connectivity issue starting at 9 seconds

I think those are spurious entries. The PhantomHelp conversion of the log has a number of missing lines of data which it apparently interprets as disconnects. But those lines are actually in the log and there were no disconnects during that flight until the end. Downlink connectivity appeared to be good throughout.

 

[EC57]

Thanks - it seems incredibly short sighted of them - I appreciate support staff follow a script and have no authority.
I asked for this issue to be escalated and re-assessed but received a fairly sanctimonious reply.

Next?
I simply can't spend more money on a product if (a) it could happen again and (b) the company who makes it won't honour their own warranty.
I wont deal with companies who do not honour their own warranty.
So I will wait for a proper response and if it is not forthcoming,
first I will sell all my other 5 Mavic batteries, chargers, controller, case, and DJI googles.
Then I will cancel my plans for future upgrade to Phantom 5 Pro or Inspire, which I was aiming to do later this year.
Then I will start researching other drone companies.

Seems so bizzare to be in this situation.
Before the Mavic I owned a Phantom 3 Pro for many years, so I can keep flying it.
It disconnected once in many years of use, and that was due to being on edge of range.
It started a RTH and within a minute was back in range & reconnected, and I carried on flying.

This is a catastrophic fault with the Mavic Pro.
If I had been flying low over land when it happened, maybe I could have retrieved the drone.
But I fly over water very often, and apart from a total failure such as this, it should be no problem.

I have replied to support again... will update this when I hear back

Sorry that you lost your equipment. Unfortunately, this is very typical for DJI. Horrible customer service.

 

[sar104]

Sorry that you lost your equipment. Unfortunately, this is very typical for DJI. Horrible customer service.

DJI has actually been quite reasonable in most cases discussed on this forum. They have replaced aircraft that crashed due to prop loss (user error), due to compass errors that were most likely caused by poor choices of takeoff location (user error) and due to power loss even though some were clearly battery ejection (user error).

The situation where they seem to have been unwilling to offer more than a 30% discount on a new aircraft is where the aircraft is lost and the flight log is inconclusive (mostly where it simply stops). Whether that's because they are unable to determine if it was user error, because they have no way to assess the honesty of the claim without any physical evidence or for some other reason is not clear. I'm sure that has resulted in some customers losing out due to equipment failure, but that perhaps needs to be recognized as an inherent hazard of flying over irrecoverable territory.

 

[pvidamaster]

Looks like my story (Lost Drone on RTH due to RC loss) ut could retrieve after 2 days.

Bottom line, had to use my Care Refresh...

 

[Flyingbrick]

I fly my Mavic Pro regularly, usually over my house capturing the sunset view I keep the firmware updated and it has been behaving normally.

But on Dec 30h the Mavic Pro suddenly disconnected & is now lost.
I was flying at a distance of 750m and was 50m high, above water - filming some yachts.
I was shooting video at the time, I had 17 satellites and 70% battery, no warnigns of any kind.
Suddenly all signal disconnected - no video, no control.

When I took off from a beach it registered the RTH location, and RTH was set to fly home at min imum height of 30m
and there were no obstacles between me & the last location of the drone.

At first I waited for the drone to RTH, and reconnect. Nothing happened.
I pushed the RTH button on the controller, it beeped but nothing else happened.
I then waited for the drone to RTH when its battery got to 30%. Nothing happened.

So my Mavic Pro disappeared, and is presumably at the bottom of the harbour.

I retrieved all data from the app including video, flight data etc
It shows what I explain above - drone is working normally,
battery has a linear decrease from 100% to 70% at point of disconnect.
17 satellites, no warnings during the flight at all.

But at the point of disconnect all data ends, and the final GPS position
is in the middle of the harbour, where the cached video ended.

Why no RTH?
Was there a power loss? If so, how?
The flight records show the battery had a linear decline from 100% to 70%
There was no low power warning. Why would the drone suddenly lose all power?
The video shows i did not hit anything. How could there be an instant 100% power loss?

Or did its firmware crash?
How could it suddenly stop functioning?


I'd appreciate any suggestions or advice.

I contacted DJI support, sent them all the data and their response was:
there is no record of a failure, and "we could not verify what happened afterwards."
so they offered me 30% discount on a replacement Mavic Pro.

But here is the thing: my Mavic is only 8months old, so still under warranty.
The flight data shows I was using the drone under completely normal circumstances,
and yet they will not honour their own warranty.

"For your claimed case CAS-1366163-J5Q3N7, we have already finished the analysis, and the result is as follows:
1. The aircraft worked in GPS mode and responsed to the pilot's command well;
2. At T=09:15, H=52 m, D=753.5 m, the pilot pushed forward the Elevator stick and moved the Rudder stick leftwards, then the record ended;
3. The home point: -41.1121000 174.8527440, the last point: -41.1183687 174.8493132.

With the record ended without any sign of abnormality, we could not verify what happened afterwards."

Timpani, which was the mobile phone or tablet? (it was not a Samsung S8, was it?)

I had a similar issue! I have a Samsung S8. I was flying my Mavic Pro, two months ago, at the height of my hands.

I took off and kept 1M for flight check (thankfully). Soon I received "aircraft disconnected". I thought, it's visual, it's just landing.

But the Mavic Pro/RC did not respond! The Mavic did not respond to any command! (but the RC screen appeared all "normal"), and also did not enter RTH!

It was then that I decided to take the extreme measure of "pick it up" and turn it off, I do not know if my nervousness or really the battery on / off button did not respond, I chose to disconnect the battery from body. (
I almost lost my fingertips, thank God)

After that I flew several times, with the same S8, without issues.

BUT, it happened again yesterday.

Now I decided to do some experiments. The test was done without propellers just leaving the Mavic Pro on, with engines spinning.

*******WARNING*****
I clearly noticed that the "disconnected aircraft" first appeared on the mobile phone, and AT THIS TIME, I saw the Mavic's green LED flashing to flashing amber (without RC!), BUT on the RC's screen everything was "normal", as if the aircraft was flying!
- Who can answer me how could it be?
*******WARNING*****

I reset the RC, with the Mavic Pro on and with engines spinning, and in less then 10s everything went back to normal (without the S8 connection), I got the green led flashing.

I conclude that it is, or dji usb type C cable, or the S8 mobile phone, because I used another mobile phone and another cable (dji usb cable) and everything worked 100%, 2 minutes later.

I have not downloaded the yesterday log yet!

(sorry about my english)

 

[Anthony]

NOTE TO EVERYONE THAT NEEDS TO TURN OFF A DJI DRONE WHEN YOU HAVE LOST CONNECTION.......

Just turn the drone 90 degrees onto it's side and it will shut off immediately.

Test it the next time you go flying.

You do not need to harm yourself.

 

[Lopez0015]

Watch this
He don’t turn off the landing protection but you can do it on settings on dji go 4

 

[Mad Mavic]

Here is link to youtube of video I was shooting when disconnect happened...

When the video ends that was the point when all signal & control was lost

Call DJI, when you get someone on the phone, ask to speak to their supervisor, they will be reluctant but press the issue. Once the supervisor is on the phone repeat the process until your are as high as you can get.

Explain everything in detail but after a short intro stop and ask if they are understanding everything you are saying, the finish.

Then tell them you want to receive a replacement drone due to malfunction which is covered under warrantee.

After you finish ask them to replete back to you what you conveyed to ensure you are both on the same page. Make certain all correspondance from this point forward are with this one individual. Speaking to various people will only confuse the issue. If all fails, ask to speak to someone at the New Jersey office.

It took me weeks to get an issue resolved and I had to climb to the top to make it happen... don’t give up. The know thousands of Mavic owners are watching ho they take care of us.

 

[Riel]

I had a similar experience a few days ago.
Clear windless day. Flying over a lake in a remote area. Mavic was on her way back with good battery. 400 meters away and at about 18 meters above, I lost all connectivity. I could do nothing to restore it. Then few minutes later she crash landed at the take off point with water streaming from her. I disconnected the battery and dried her for about 45 minuts with a hair dryer. But she has died.
Mystery! The footage shows her flying along and then the recording ends with only a little interference in the video, but no indication of what may have gone wrong.
I was using an iPad with the controller.
I have tested the controller on my spare Mavic and that is fine.
Any ideas?

 

[sar104]

I had a similar experience a few days ago.
Clear windless day. Flying over a lake in a remote area. Mavic was on her way back with good battery. 400 meters away and at about 18 meters above, I lost all connectivity. I could do nothing to restore it. Then few minutes later she crash landed at the take off point with water streaming from her. I disconnected the battery and dried her for about 45 minuts with a hair dryer. But she has died.
Mystery! The footage shows her flying along and then the recording ends with only a little interference in the video, but no indication of what may have gone wrong.
I was using an iPad with the controller.
I have tested the controller on my spare Mavic and that is fine.
Any ideas?

I suggest posting the mobile device txt and DAT flight logs. The aircraft DAT file would be even more useful but, if the aircraft won't power up, will be difficult to get.

Aircraft V3 DAT file: How to retrieve a V3 .DAT File from the AC

TXT log: DJI Flight Log Viewer | Phantom Help

Mobile device DAT file: How to retrieve a V3.DAT from the tablet