Mavic disconnected, no RTH & is lost

[kakao]

Sorry for your loss mate, you shouldn't take their no as an answer.
They don't know what happened with the aircraft but at the same time they couldn't find pilot's error.

Its a bit fishy DJI on your end ..

 

[colinfowler]

Sorry mate didn't mean to come across harsh, long nightshift, should really get to my bed.

At around 5min 30s he is flying a heading about 15 degrees off that of final position RTH .

Assuming he is full pitch forward , he is averaging around 9mph, so a 13mph+ headwind on RTH if he had OA switched on could be possible.

He did only have 750m to travel and 70% battery.

Also reported no warnings during flight, I took this to include wind.

If wind was the issue he could have switched to sport mode had it not disconnected.

Would be great if Mavic could automatically switch to sport mode or increase max speed on RTH if it is not making progress when full pitch.

no prob.
I see so many disconnects and not returning.
possibly there was no high wind warning due to the disconnect.
don't know if it was a total app and rc disconnect, if it was switching to sport and manual return would not be an option

 

[SouthernComfort]

Did you try anything aside from RTH? Try any stick inputs to see if it would respond at all? Just curious.

 

[sar104]

That makes no sense. If it's returning at 15mph, it's returning at 15mph.

There was no wind warnings during flight, it's all to easy to suggest things that might have happened.

People seem to naturally geared towards blaming pilot on here.

In fact there were wind warnings - at 177 s, 205 s and 353 s. However, as far as I can see the wind was only 12 - 15 mph out of the NNW, so that doesn't really explain the disconnect or the lack of RTH, since the aircraft should have been able to make at least 5 mph into the headwind in RTH, and would have returned in about 5 minutes. It also should have reconnected during that time since the downlink and uplink was good in that area.

Looks to me most likely a power issue - either a battery disconnect or a bad connection to the main board.

 

[teslar]

Question? Were you using Tripod mode when filming the regatta, because if the Mavic disconnects of has vision location problems which is common over water this would cause the Mavic to drop into ATTI mode which would not initiate RTH you would have to fly it home manually without the aid of GPS. This is where being able to read the tails light flashes on a MAVIC comes in handy

In this type of circumstance the best thing to do it switch to Sport mode and hit RTH as once in ATTI mode the MAVIC will not enter GPS mode until told to do so. Switching to sport mode will re enable GPS and disable downward vision and collision avoidance and give you the fastest return home speed which will help fight wind

 

[sar104]

Question? Were you using Tripod mode when filming the regatta, because if the Mavic disconnects of has vision location problems which is common over water this would cause the Mavic to drop into ATTI mode which would not initiate RTH you would have to fly it home manually without the aid of GPS. This is where being able to read the tails light flashes on a MAVIC comes in handy

In this type of circumstance the best thing to do it switch to Sport mode and hit RTH as once in ATTI mode the MAVIC will not enter GPS mode until told to do so. Switching to sport mode will re enable GPS and disable downward vision and collision avoidance and give you the fastest return home speed which will help fight wind

How is any of that going to work once the aircraft has disconnected from the RC, as in this case?

 

[teslar]

How is any of that going to work once the aircraft has disconnected from the RC, as in this case?

I asked question and explained why I was asking.

Also looking at the map of the flight it looked like the mavic was in P mode which also defaults to ATTI if it losses Connection. Both these cases would explain why there was no RTH

Asking question often brings out more information which might help. Never assume you have the full story or facts to hand

Another Question did the RC report lost connection or only the app ?

 

[jakub]

Just a quick question:are you sure your mavic was set to return to home when signal is lost? And not to hover?

 

[bruceb]

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."

Im new to forum iv lost 1 mavicpro in the gulf of mexico, rth malfunctioned but dji could not verify do i was pffered a discount i purchased a reman mavic.since that experience the new mavic has had failures in the rth mode, luckly all hapened where i could manually fly it home im neginning to doubt the technology and manufacturer. And theirattention to detail still love my mavic but its not as nuch fun now that it is not trust worthy.

 

[sar104]

I asked question and explained why I was asking.

Also looking at the map of the flight it looked like the mavic was in P mode which also defaults to ATTI if it losses Connection. Both these cases would explain why there was no RTH

Asking question often brings out more information which might help. Never assume you have the full story or facts to hand

Another Question did the RC report lost connection or only the app ?

That's not correct. The aircraft does not switch from P-GPS to ATTI on RC disconnect - obviously, since if it did then failsafe RTH would never work. It only switches to ATTI if (a) you switch it manually to ATTI, (b) it loses GPS lock or (c) the IMU sensor fusion scheme fails due to disagreement between the inertial sensors and the magnetic/GPS data.

The OP stated that the aircraft disconnected - that means an RC–aircraft disconnect.

 

[teslar]

That's not correct. The aircraft does not switch from P-GPS to ATTI on RC disconnect - obviously, since if it did then failsafe RTH would never work. It only switches to ATTI if (a) you switch it manually to ATTI, (b) it loses GPS lock or (c) the IMU sensor fusion scheme fails due to disagreement between the inertial sensors and the magnetic/GPS data.

The OP stated that the aircraft disconnected - that means an RC–aircraft disconnect.

I know you seem to consider yourself an expert from previous posts and appreciate you helping people. But it’s up to the OP to determine if a post is helpful. That not your job

I’ll refer you to this page in the DJI manual which many overlook or don’t even download

So as I said if the OP was using Tripod or some other program mode that relies on the camera it would result in ATTI mode of the camera failed to lock on and also fail RTH

I asked the OP a question because it may be that his description of the event was not as complete as he intended. Only the OP can answer that one. You were not there and can’t speak for him. Neither does that data speak for him as we already know it hasn’t thrown any light on what’s happened

 

[Callum]

I know you seem to consider yourself an expert from previous posts and appreciate you helping people. But it’s up to the OP to determine if a post is helpful. That not your job

I’ll refer you to this page in the DJI manual which many overlook or don’t even download

So as I said if the OP was using Tripod or some other program mode that relies on the camera it would result in ATTI mode of the camera failed to lock on and also fail RTH

I asked the OP a question because it may be that his description of the event was not as complete as he intended. Only the OP can answer that one. You were not there and can’t speak for him. Neither does that data speak for him as we already know it hasn’t thrown any light on what’s happened

The vision system is a secondary positioning system to the primary GPS.

Vision positioning can only operate under 13m and in this instance OP was over 300ft.

On loss of GPS under 13m the aircraft switches to P-Opti and if vision is poor ATTI.

At higher altitudes it switches straight to ATTI on event of GPS loss or IMU exception.

VPS does not use the main camera and is not related to smart features like active track.

 

[sar104]

I know you seem to consider yourself an expert from previous posts and appreciate you helping people. But it’s up to the OP to determine if a post is helpful. That not your job

I’ll refer you to this page in the DJI manual which many overlook or don’t even download

So as I said if the OP was using Tripod or some other program mode that relies on the camera it would result in ATTI mode of the camera failed to lock on and also fail RTH

I asked the OP a question because it may be that his description of the event was not as complete as he intended. Only the OP can answer that one. You were not there and can’t speak for him. Neither does that data speak for him as we already know it hasn’t thrown any light on what’s happened

I'm sorry, but you appear to have completely misunderstood this functionality. The manual page that you so kindly referenced clearly states that it switches to ATTI if it loses both GPS and vision positioning, not if it loses connection, which is what you incorrectly stated in post #27. And so I was not commenting on whether your post was helpful (although it obviously wasn't) - I was pointing out that it was simply wrong.

 

[geigy]

Sorry this happened!

Looks like power loss to me, and DJI should cover it. If that's the case, you could hire a boat or diver to retrieve the drone near the location the power went out. There may be enough physical evidence left for DJI to honor the warranty, which they will generally do if the evidence is there, which in the case of a sudden power loss is not.

 

[teslar]

I'm sorry, but you appear to have completely misunderstood this functionality. The manual page that you so kindly referenced clearly states that it switches to ATTI if it loses both GPS and vision positioning, not if it loses connection, which is what you incorrectly stated in post #27. And so I was not commenting on whether your post was helpful (although it obviously wasn't) - I was pointing out that it was simply wrong.

Having watched a number of videos regarding issues when flying over water. There are various schools of though regarding the use of vision sensors and there impact. I know they are only meant to impact at low altitude but I and others have seen things go Array at higher altitudes.

My original response to the OP was a query about him using tripod as whether he was or not could have a bearing here and could result in ATTI mode. It seemed evident to me that he was using some sort of flight mode given the neat circle he carved around the map of the area. Therefore my post was aimed at teasing out other factors that might have contributed

I’m trying to keep an open mind here as we don’t seem to have all the data or all the facts and neither has DJI

Something is missing here. Of course it could have been a catastrophic failure but it’s worth exploring other factors which could have contributed.

I’m quite happy to learn from others experience I don’t think anyone fully understands these issues or there would not be so many stories like these

 

[timpani]

I wasn't in tripod mode. RTH was set - not hover. Verified in flight data RTH GPS position and minimum height of 30m. It was the remote control that disconnected... & at same time all video & data to the app stopped, of course... That was what scared me most at first, as have had situations in the past (with Mavic and P3P) where video has stopped but still have control. When it disconnected I of course tried moving controls and also hit RTH button, which started beeping... throughout I could see the remote trying to reconnect, which it never sucessfully did.
Re a boat and diver, its over a week ago now - tides could have dragged it anywhere...

 

[teslar]

Thanks for clarifying and sorry you’ve had such a painful experience. It’s no wonder you’ve lost trust when such a random thing happens

 

[Mred32]

That was a total and catastrophic failure of some kind. Either it was hit by something and the battery was ejected, the battery came away from the contacts somehow, or total battery failure.
The drone died suddenly, it didn't just disconnect and drift away.
My opinion.

 

[sticks07]

My thought is that the battery became dislodged from the MP. I have heard of this happening if the battery isn't seated properly and would also explain the sudden loss of 'everything'. The battery would have dropped along with the MP like a stone. No comfort, but a possible explanation.

 

[jakub]

My thought is that the battery became dislodged from the MP. I have heard of this happening if the battery isn't seated properly and would also explain the sudden loss of 'everything'. The battery would have dropped along with the MP like a stone. No comfort, but a possible explanation.

But why would that happen? You mean that the battery wasn't inserted properly or that battery holders were damaged in some way?