Hi Team,

I flew with Mavic Air a couple of days ago and in some moment I lost  control of my MA. It started to slide to a side, and I was unable to  control it. Unfortunately, I don't have video of the incident, but I have flight logs. As I didn't find any log that will help me to understand why it happened, please, can you look for it and help?

Here are the logs:
https://drive.google.com/file/d/ ... Tv/view?usp=sharing

Thank you in advance.

Maki

Hi there, I''m really sorry to hear the incident. Please contact our support team to start up a case: (https://www.dji.com/support?site=brandsite&from=nav). We have the professional data analysis team who would do their best to find out the crash reason and then the corresponding resolution would be provide. You can provide your case number here in case you need further assistance.

Hi Maki,

Had a look at your flight.

Did you find your MA after the crash?

It look like you have flown into the trees.No errors in your log.

cheers
JJB

JJBspark Posted at 2018-10-14 12:08
Hi Maki,

Had a look at your flight.

Hi JJBspark,
Thank you for your time and effort, I really appreciate it.

Yes, I have found it in the bush under the trees. Yeah, it is flown into the trees, but I didn't have any control over the MA
I have tried to go to 50 meters up into the air and take some pictures, but it suddenly started to lose height and "slide" to a side.

After this incident, I didn't try to fly again as I'm worried that the same thing will occur again :/

What did you take off from? Grass, concrete, car bonnet etc?

Hi TroutboyNZ,

It was launched from hand (above grass) - I know that was not the smartest move, but I have done that before and I didn't have any problems.

Maki87 Posted at 2018-10-14 12:59
Hi JJBspark,
Thank you for your time and effort, I really appreciate it.

Hi,

Difficult to say what have happend, i see a lot of full stick travel. Full down and the MA did respond to that.

One would expect to see compass and/or imu errors if that was the cause of this flight behaviour.

The screen shot of FRAP was the wrong one, its corrected now. see your input on the sticks.

cheers
JJB

Tonight I also lost my Mavic Air...
In urban enviroment and at a distance of about 120m and 80m height while taking pics the screen on the phone froze, the lights went out and the drone had been hovering for about 18 minutes...
We saw it just before it crashed but we could not estimate well its position due to the low illumination of the night...
It was totally unexpected...
The point is that the drone drifted too much without reason...
I hope DJI help me find it out...

SioÜ Posted at 2018-10-15 10:57
Tonight I also lost my Mavic Air...
In urban enviroment and at a distance of about 120m and 80m height while taking pics the screen on the phone froze, the lights went out and the drone had been hovering for about 18 minutes...
We saw it just before it crashed but we could not estimate well its position due to the low illumination of the night...

Hi SioU,

if you like upload your flightrecord on here.

cheers
JJB

JJBspark Posted at 2018-10-14 22:43
Hi,

Difficult to say what have happend, i see a lot of full stick travel. Full down and the MA did respond to that.

The thing is that I tried to take pictures from 50 meters high, but when it started to slide, I've tried to get it back, and that's the reason for full stick travel. Never mind, if I catch some time tomorrow I'll try to fly with MA and see if it works :/

JJBspark - thanks anyway

@SioU that happened after the latest firmware update?

Hi, I´m new poster to the forum, until now have been just lurking in the shadows and reading thru the posts. Sadly I lost my mavic air yesterday and I´m still in shock and trying to figure out what really happened.

I do have the care package but the drone is in the sea and impossible to retrieve atleast before the ice fully melts and even after that its very unlikely that I would be able to get the remains up from the bottom.
I have created a ticket, but don´t have high hopes since the drone is sleeping now with fishes.

So...
I was visiting our summer cottage and because the weather was still and sea was almost mirrorlike I decided to film a some ice floes which were close to the iceline in hopes of "cool" reflections (pun intented and unsuitable for situation).

Because of the snow and ice, I had to launch the drone from the porch of our cottage with just 4 gps satellites. I flew the drone a couple of meters away from the cottage and waited for better gps coverage, getting 10 satellites. After getting the camera to right settings I did a slow circle around a nice looking ice floe and was just getting ready to move to film next one when the drone suddenly tilted and started to slide in speeding manner towards the sun for some reason. I flew at quite low altitude, between
I tried to lift it higher and turn the heading to gain full control of the drone but it just kept on gaining speed and eventually started losing height. It was exceeding 90 km/h before hitting water and after skipping once sunk to the sea.  Drone was not in sport mode and I´m puzzled how it could reach such high speed before hitting the water. I´m not sure if I did the right moves when controlling the drone, but it felt like it would thing that its up/down axis would had tilted 10-20 degrees for some reason.  I tried to prevent it from hitting water but failed miserably.

I tried to link the flight log here, but apparently Im not allowed to ad links to posts yet. *Sigh
I have uploaded it to the phantomhelp flight log viewer, but cant link it here for some reason.

I´m pretty devastated for the loss, any help to share light to the accident is much appreciated.Your´s Wili

wow, four satellites, launched to anticipate ten satellites.
this means zone familiarity from prior flight experiences.
if familiar with zone, then how can incident ensue?
description reveals craft autonomously ignored sticks command. did owner receive "homepoint recorded" affirm or not?

cutis Posted at 5-6 11:04
wow, four satellites, launched to anticipate ten satellites.
this means zone familiarity from prior flight experiences.
if familiar with zone, then how can incident ensue?

Yes, I have flown there before, location is our summer cottage. most of the flight I had 19-20 satellites.
Drone recorded the homepoint in front of the cottage, where it was waiting for satellites.

Incident happened because of the sudden and unexpected nature of the events. Flight lasted  in total under 2 minutes. After problems started to occur, drone was lost within 10 seconds, maybe 100-150 meters from starting point.

(still dont have permission to link the url to the log, sorry)

https://www.phantomhelp.com/LogViewer/NVW9KO4UJ6QYJEPL43DD/

I hope that this post goes through... link should show the log.
Wili

i am confused of why craft disobey the sticks.
only vision protect overrides sticks if actually acting (vision protect overridden high winds combat attitude).
i am not confused downwards vision can get confused by the monotonous ground picture, in this instance sleek icing monotony.
last, it's unproveable, the coding laid inside all three devices are in fact integrity as factory intended, and NOT CORRUPTED

cutis Posted at 5-6 17:13
i am confused of why craft disobey the sticks.
only vision protect overrides sticks if actually acting (vision protect overridden high winds combat attitude).
i am not confused downwards vision can get confused by the monotonous ground picture, in this instance sleek icing monotony.

I have the same problem, the loss of control was scary and I still dont know why the drone did what it did.

Day was almost windless, I was shooting the Ice floes because of almost perfect reflections from the sea, so there were no issues from high winds.  Problems started to occur when I turned the drone towards the sun, which also had a reflection in the water. Don´t know if that has anything to do with the strange tilt but it tilted towards the sun and kept on going towards it no matter the stick input. ( As far as I can tell)

Strange things start to happen after 1:50:00 in the log. The drone stops and without input it tilts and starts to speed. I tried to get it higher and under control, but failed.

Wili Posted at 5-8 10:59
Strange things start to happen after 1:50:00 in the log. The drone stops and without input it tilts and starts to speed. I tried to get it higher and under control, but failed.

Flight is very low to the ground, and the craft struggles to get sufficient power - at the same time, the speed is substantial. No trace of connection problems, and going by the last 3 seconds of the flight the AC traveled 44m away from the home point thus doing about 53km/h (44/3=14.7m/s). All while quickly turning heading. Is it possible that there was substantial wind at that distance?

DJ-MA Posted at 5-8 11:49
Flight is very low to the ground, and the craft struggles to get sufficient power - at the same time, the speed is substantial. No trace of connection problems, and going by the last 3 seconds of the flight the AC traveled 44m away from the home point thus doing about 53km/h (44/3=14.7m/s). All while quickly turning heading. Is it possible that there was substantial wind at that distance?

[view_image]

There were almost 0 wind, clear reflections from water was the reason I decided to take the video and fly with the drone.
Flight was low but 0 height was about 1.5-2 meters above sealevel, which should be added to the numbers. I have asked  my friend, who has a weather station to check the wind conditions from the evening, but the wind was not strong enough to move tree pranches or cause ripples on the water, so it should be somewhere between 0 to 3 m/sm which shouldnt be a problem to the drone in any way.

High force usage was most likely connected to my futile efforts to prevent the drone from sliding to water and lifting it higher.  I have thought it a lot, it felt like drone had lost the ability to accurately stay level and not being able to hover. If you checked the stick input, you saw that I used almost 0 right stick  during the effort to gain altitude. Drone had strong gps connection with 20 satellites, and didnt show any warnings on screen.

that warning on 5 s is puzzling, first time I saw that. Maximum altitude was set to 120meters so that shouldnt  be there.

Wili Posted at 5-8 12:47
There were almost 0 wind, clear reflections from water was the reason I decided to take the video and fly with the drone.
Flight was low but 0 height was about 1.5-2 meters above sealevel, which should be added to the numbers. I have asked  my friend, who has a weather station to check the wind conditions from the evening, but the wind was not strong enough to move tree pranches or cause ripples on the water, so it should be somewhere between 0 to 3 m/sm which shouldnt be a problem to the drone in any way.

If you upload your log to healthydrones.com you can see all these (and some more) data; including temperature/wind direction (3.7 C, 3.7m/h). You can also have a look at the full log (download csv) or even use that excellent program JJB made (search forum for it).
Any chance your battery was too cold to deliver the power required? (Ice on propellorblades?)

DJ-MA Posted at 5-9 06:18
If you upload your log to healthydrones.com you can see all these (and some more) data; including temperature/wind direction (3.7 C, 3.7m/h). You can also have a look at the full log (download csv) or even use that excellent program JJB made (search forum for it).
Any chance your battery was too cold to deliver the power required? (Ice on propellorblades?)

Thank you for the links and advice, I will look into those. Ice is not  option, the flight was short just 2 minutes and there were no fog or anything which would cause that.  Drone was inside before the flight, +21c, so the battery should be at similar temp when starting.

I did got message from DJI after log checking and I will be getting a new drone as warranty replacement, so far I haven´t got any details about what was found.  

*Update

Dji data analysis suggested that compass had  suffered interference and caused the drone to become uncontrollable.

Thank you all for the help and advice.
Wili

will do thanks