Hi Guys

I have just crashed my Mavic Pro..

Here's the jist of it:
I have been using this bird for a close to a year now with no problems

On the 15/3/18,
- I updated my Mavic's RX and bird to the latest DJI GO firmware so as to update the NFZ and advisories.


On the 16/3/18,
- I performed flight for a test run and the new firmware that has been installed on it. For no more than 50 seconds, my bird has crashed on the side of the building. (I understand the rules of not flying near buildings, however I must reiterate that I took off from a safe enough distance, at least 30m away that it did not pose an immediate cause of concern)

During the flight:
- Throttled up to ensure the Mavic's usual characteristics are still as per normal
- After releasing throttle input, the DJI GO app warned me that I was at MAX Altitude (30 meters/90 feet). It was at this point, I realised that my Mavic was still gaining altitude.
- Less than 5 seconds later, warning signs from the Mavic's LED tells me something is very wrong:
  1) Mavic was no higher than 15 meters/45 feet , tops.
  2) Yellow flashing lights for a few seconds (Mavic also starts to drift away from me, I had minimal control of Pitch and Roll input, increasingly becoming uncontrollable. The mavic was now heading towards the building at this point)
  3) Rapid Red flashing lights (Mavic increasingly loses throttle power)

- At this point, I did what I could react at that situation.
  1) Throttle up to regain altitude
  2) Steer the Mavic towards my location

- No response from the Mavic. At my final desperation, I depressed the RTH button, but an error called out was "NO RTH".
- Among everything, the one thing I did find find strange was my Mavic was still streaming a continuos video feed to the RX as I could watch my bird fly helplessly towards the building head on and the video feed black out the same time I looked back on the screen.


Luckily it dropped some altitude before it crashed and nobody on the ground was nearby and injured

Black box data revealed that before the MAX Altitude read-out, I had lost VPS measurement. Soon after that, I lost GPS Signals, but only to regain it momentarily afterwards. Data shows that both signals were back online, a few seconds before impact.


Sorry for the lengthy post, I had written down the sequence of events as soon as it happened, so as to not leave out any details.
If anyone is able to help me or if any DJI support team could assist me, it would be helpful.

Thank You Very Much
Toshi

It looks like a product issue to contact dji repair on vietnam  to send your unit for damage analysis to determine if it is a product issue or not

Sorry to hear that you crashed your Mavic.

Not much I can add  other then after you updated did you recheck ALL your controller setting to be sure they didn't change?

If you can upload your flight data Log viewer . I know there is someone on the Forum will try to help.

B1houdini Posted at 2018-3-16 11:51
Sorry to hear that you crashed your Mavic.

Not much I can add  other then after you updated did you recheck ALL your controller setting to be sure they didn't change?

http://www.phantomhelp.com/LogViewer/KB4WG4CIFNXMFUW80KL0/

Here is the FDR

As I was flying Line Of Sight, I realised the Altitude Indicator was giving it false readings as I was probably no more than 15 meters (45 feet) than the indicated 30 meters (90 feet).

Mr. Information Posted at 2018-3-16 10:06
It looks like a product issue to contact dji repair on vietnam  to send your unit for damage analysis to determine if it is a product issue or not

Yeah

I'm on a holiday in HCM though, so I would go back to Singapore to call on their help support there.

Checking in the forums here first to see if anyone has the same issue, and if it's related to the new firmware

Sushioshi Posted at 2018-3-16 18:53
Yeah

I'm on a holiday in HCM though, so I would go back to Singapore to call on their help support there.

Toshi,
sorry to read about your crash.

Your logs revealed following:
- take off after 2 seconds
- not enough satellites (4) for sufficient GPS health (0 during the whole flight)
- therefore flight controller switched to ATTI mode and remaind in this mode during the whole flight (hence the yellow flashing)
- still in ATTI mode and you had no downward vision sensors active, you were
  not able to climb more than 30m.
- the drifting was caused by wind influence and you had no GPS lock

It seems to me, that you had no experience to control the aircraft while in
ATTI mode. Your stick inputs where not efficient enough to bring the aircraft to a safe landing place.
Pressing RTH button made no sense to the flight controller, because it does not know its current location nor does it know the home coordinates. (message: NO RTH)

I hope that info helped.
//K.

Keule Posted at 2018-3-16 20:36
Toshi,
sorry to read about your crash.

Hi K,

Yes I understand that the Mavic entered ATTI mode

However, I was near my Mavic before it drifted away and applied in counter actions to prevent the Mavic from straying away from the wind .  The wind at that time was no more than 8km/h

Also, it does not answer my worries, as to why my Mavic was flashing Red rapidly as it strayed away. At that time, any controls that I have applied were not reflected on the Mavic  

Toshi

Sushioshi Posted at 2018-3-16 22:02
Hi K,

Yes I understand that the Mavic entered ATTI mode

Toshi,

flashing red indicates an IMU error. If that's direct related to ATTI mode, i'm just guessing - maybe.
More infos can be retrieved by the onboard Black Box. (the FLYXXX.DAT)

Have you done a compass and/or IMU calibration after your update and prior your flight?

Keule Posted at 2018-3-16 22:09
Toshi,

flashing red indicates an IMU error. If that's direct related to ATTI mode, i'm just guessing - maybe.

Hi Keule,

No I haven't. I only calibrate it when prompted.

May I know what is an IMU? Is such cases recoverable by DJI Support? My Mavic is badly damaged due to this.

Toshi

Sushioshi Posted at 2018-3-17 01:08
Hi Keule,

No I haven't. I only calibrate it when prompted.

Toshi,

IMU = Inertial Measurment Unit.
Have a look at this video on how to calibrate:

Keule Posted at 2018-3-17 08:53
Toshi,

IMU = Inertial Measurment Unit.

Hi Keule
Looking from this, it most likely be an error with the IMU.

It best explains the error readout of the altimeter & attitude as well as "NIL" readings from the vps.
However, this is my best deduction from what you've mentioned the data available from the black box. I'll see what I can discuss with DJI Support.

Thanks!

Toshi

Sushioshi Posted at 2018-3-17 18:20
Hi Keule
Looking from this, it most likely be an error with the IMU.

Sorry for the crash. Did you contact our support and start a case? If you have doubt, please provide the flight data to our support to locate the problem.

DJI Elektra Posted at 2018-3-18 22:10
Sorry for the crash. Did you contact our support and start a case? If you have doubt, please provide the flight data to our support to locate the problem.

Hi Elektra

I only just got back from Vietnam

I'll contact the DJI Singapore team soon. Hopefully I'll be able to find the root cause of the issue.

The Mavic's body has become slightly wrecked and will not fit the battery anymore. I am not able to extract the on board FDR data from it, apart from the FDR recorded by the DJI GO app. Is there any way to extract the on board data without the battery?

DJI Elektra Posted at 2018-3-18 22:10
Sorry for the crash. Did you contact our support and start a case? If you have doubt, please provide the flight data to our support to locate the problem.

http://www.phantomhelp.com/LogViewer/KB4WG4CIFNXMFUW80KL0/

The FDR as recorded by the DJI GO App.

However, there is some discrepancy on the Altitude. It records 30m (90 feet) AGL, but at that time, it was no more than 15m (45 feet). On top of it, the VPS reading was missing, as well as rapid Yellow and Red flashing lights on the Mavic as it drifted away, even with counteractive inputs. Winds at that time was no more than 8km/h as recorded by Google Maps.

Please advice, thank you!


Toshi

Sushioshi Posted at 2018-3-19 08:07
http://www.phantomhelp.com/LogViewer/KB4WG4CIFNXMFUW80KL0/

The FDR as recorded by the DJI GO App.

Thanks for your update. If you have case number, please leave it here. If your drone is under warranty, I would recommend you apply for the data analysis to locate the problem. Hope it will be solved soon.