Mavic 2 Flyaway Help

[ChrisDodds86]

Hi,

This is my first post however I'd have hoped my first post wouldn't have been regarding the loss of my drone. I really would appreciate any help or light anyone may be able to provide. I'm in complete dispare that I've lost my drone.

I was flying my drone yesterday afternoon whilst on holiday in Portugal when it seems to have malfunctioned lost connection and disappeared.

My drone had only just taken off (20 or so seconds into flight) with a fully charged battery when around 200ft away and still within visual line of sight from the take off position it began to make a strange noise and then disappeared out of sight. It sounded as though the motors suddenly and rapidly increased in speed and malfunctioned even though i had just began to reduce a little height.

I have been unable to locate the drone after spending a full day searching for for it in within a wide area under the location it was last seen above. I have also used the locate my drone function within the app however this has also proven unsuccessful. The last known location appears to be where the drone lost contact with controller over 200ft in the air and around 200ft away from takeoff position, traveling directly ahead of my location.

The weather was perfect for flying, clear visibility, dry, blue skies, satalites locked on and very little wind.

I had began my flight by competing a pre flight health check of the drone, fusilage, arms, rotors and gimbal. I then took off completed a manouver check as I always do after takeoff and before flying off. A simple hover then left right, back forwards, up and down to ensure the aircraft is responding correctly. The drone was working as expected at this stage.

I then proceeded to fly towards the intended target of interest (an old farm outhouse) to capture with photo / video. I was pushing forwards on both the left and right controls to gain height and move forwards. Just as I approached the hotel perimeter bushes (these are around 7-10ft ) and was about to enter the overgrown wasteland beyond the hotel perimeter I began looking at my phone screen connected to the controller to line up my camera with the subject to start filming. At this point I decided to start to reduce my height as I was around 200ft above ground level and well above the tallest bushes and trees in the area of wasteland. The bushes and small trees would be no more than 15-20 ft tall as a maximum. Throughout the flight I remained fully within VLOS.

As I pulled down on the controller to reduce a little height as I approached the old farm outhouse I heard the motors produce a sound I can only describe as sudden overspeed as if the motors were malfunctioning (this was not a sound I had heard the drone make before in any of my flights).

At the same moment the controller disconnected and I then immediately looked up but the drone had disappeared. I cannot confirm if the drone continued to fly away or of it plumented to the ground. I could hear no thud of hitting ground or rustling if the drone had falllen into a tree. The last image on my remote was in black and white (as disconected). The image was level and suggested no change in direction still around 200 ft above ground maintaing a heading towards the target subject. I attempted to press the return home button on the remote however this did not work. (I have used this before and understand how this operates). I waited for 40 minutes in the event the drone returned home itself. The drone did not return. I then scoured the area under the drone where it had last been seen. This was both within the hotel boundaries and the wasteland beyond the hotel perimeter. This proved difficult due to fences, uneven terrain and inaccessible areas due to shrubbery, trees etc.

The wasteland was long grass (3ft or so with patches of dry soil, shrubbery, scattered with the odd tree 15-20ft in height with no electrical devices to cause interference on the ground and no power cables in the area. (There appears to have been a malfunction of software or hardware disconecting the aircraft from controller and causing the loss and flyaway of the drone.

This was my last day of holiday with my family and I have now returned home today. As such I am unable to continue a further search. Searching at the time was dangerous as I was told wild dogs and snakes lived within the wasteland and I should not enter. Regardless of this I spent my final day of holiday searching frantically for my drone with no luck.

Please may I ask your thoughts on this.

I feel that this was a malfunction and the drone failed to operate as intended.

I've emailed DJI this morning however I'm currently awaiting their response. Would have emailed sooner however due to travel home I only got home around half 4 this morning. Drive home from Birmingham airport to Newcastle area.

Appreciate anyone's help on this.

Kind regards,
Chris Dodds

 

[afarkas]

Looks like failure... Was it a hot day?
Im sorry

 

[ChrisDodds86]

Looks like failure... Was it a hot day?
Im sorry

Thanks for your repsonse.

It was 23 degrees Celsius. So not too hot. The battery pack was registering 31 degrees Celsius at last recorded point of contact in logs.

 

[Meta4]

There's very little information to work with for this incident.
The data shows you launching and flying at full stick forward while climbing at max speed for 21 seconds ... and the data just stops.
At the end of the recorded data, the drone is still in stable flight with a full battery so we can eliminate collision as a possibility and it's reasonable to assume the drone kept flying after losing signal.

Your drone is programmed to RTH on loss of signal (unless you change the default setting - which you did not.
The change of sound would have been the drone stopping horizontal flight and climbing to RTH height.
Unfortunately you had your RTH height set to the ridiculous level of 500 metres so the drone would have climbed a long way before beginning to come home.

The weather was perfect for flying, clear visibility, dry, blue skies, satalites locked on and very little wind.

I wonder about the wind level as a strong wind would explain the loss of the drone.
There's not enough data to tell the whole story but there are a few more fragments of evidence to look at.

The data shows that you had obstacle avoidance disabled and went full right stick from 7.9 seconds.
At 15.9 sec it had reached a horizontal speed of 7 metres/sec at a height of 52 metres.
After another 5 seconds (end of recorded data) the drone was at 72 metres but the speed had only increased to 7.8 m/s despite the right stick being full forward.

In still air the drone can zip along at 16 m/s with the OA disabled.
That your horizontal speed peaked at less than 8 m/s suggests that the drone was pushing hard against a significant wind 72 metres up.
We can only guess what the wind speed would have been 500 metres up ... but it would have been much stronger than at 72 metres.

I don't like making guesses but the available evidence is pointing to the drone being blown away by high level winds once it had climbed to the set RTH height of 500 metres.

I attempted to press the return home button on the remote however this did not work.

Without control signal, the button won't have any effect, but the drone is programmed to RTH on loss of signal anyway.

I feel that this was a malfunction and the drone failed to operate as intended.

I'd like to see some evidence of a malfunction before blaming the drone.

 

[davemorts]

Airdata shows the wind at 8.2 Mph, this would be doubled at 100 ft. It could be 40 or 50 Mph maybe more at 1640 ft.
looks like the mavic was blown away with the wind.

 

[sar104]

Since this incident has been discussed at some length on a different website I'll just post the results from that here. It looks like a sudden failure - power or FC, and likely resulted in the aircraft immediately falling to the ground. Estimation of the trajectory based on the aircraft velocity, height and wind speed gives the following:

 

[sar104]

Airdata shows the wind at 8.2 Mph, this would be doubled at 100 ft. It could be 40 or 50 Mph maybe more at 1640 ft.
looks like the mavic was blown away with the wind.

Except the aircraft wasn't at 1640 ft, it was at 235 ft, and the calculated wind at that height was 12 mph out of the south (187°), i.e. back towards the home point. It did not blow away.

 

[Meta4]

It looks like a sudden failure - power or FC, and likely resulted in the aircraft immediately falling to the ground.

That fits the recorded data and could well be the explanation, but what did you make of the comment?: it began to make a strange noise and then disappeared out of sight. It sounded as though the motors suddenly and rapidly increased in speed
When power is shut off, the Mavic just goes quiet.

 

[webvan]

How are you seeing that RTH was set to 500 meters?

Sorry for your loss, happened to me once with a Bebop and I spent several hours worrying it had maybe be caused damaged (it hadn't as I found it the next day) so at least thats something you can take solace in.

 

[sar104]

That fits the recorded data and could well be the explanation, but what did you make of the comment?: it began to make a strange noise and then disappeared out of sight. It sounded as though the motors suddenly and rapidly increased in speed
When power is shut off, the Mavic just goes quiet.

That was before the motors shut down, and I think the noise was probably just a result of the sudden change in stick input:



At a height of 235 ft and a distance of 250 ft from the home point, if you can see the aircraft then obviously it cannot disappear. The OP obviously lost sight of it, either just before or just after the problem occurred.