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Ocean Crash - Resolved

juzzyx

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Hi! I would appreciate it so so much if someone could examine my flight logs, short story is I got disconnected from controller multiple times (phone and drone) and had no control of mavic and it crashed into the ocean and DJI won't honour warranty or care refresh (ocean crash refresh not eligible anyway.)
DJI claims it was too windy, there was no wind on the ground. I believe the controller was the issue however DJI wont have a bar of it, here is my story (this i send to DJI)

This is my second flight since my controller was repaired after the mainboard failed. below is the sequence of events

*The mavic flew normal for the first minute and then the controller disconnected from the phone, not physically it just disconnected and the mavic headed out to sea accending.
*After around 2 minutes I tried to bring the mavic back by engaging return to home on controller (the home point was set where it took off) When RTH was engaged the mavic then flew higher and further away, The connection to the phone returned
*I disengaged RTH as the mavic was far out over the ocean, I attempted to fly the mavic back towards me but my actions on the controller were not acting upon the mavic (full forward towards my direction) the mavic just kept going outwards
*The controller disconnected and reconnected to the phone numerous times (unable to use phone controls) *engaged sport mode to add more power to manually fly home to no avail.
* RTH engaged again due to disconnect from controller and it did not return *manually attempted recovery *Reengaged RTH mavic appeared to be hovering and no control stick input would happen
*This cycle kept happening until the mavic lost all of its battery and at 14% began a decent into the ocean *battery critically depleted and mavic fell into ocean around 1-2kms off shore I recorded the final moments of this crash as evidence. I have attached video and images to this email and synced my flight data to DJI servers. I have more videos prior to this failure also if needed, Thank You.

DJI reply:
1. The aircraft worked in GPS mode, and there was wind affecting the aircraft during the flight;
2. T=06-41, h=212 m, d=616.5 m, the aircraft in Go-home mode, but it could not RTH successfully due to the wind;
3. T=10-45, h=212 m, d=992.9 m, the aircraft was still under the interference of the wind from Northwest direction;
4. T=11-35, h=212 m, d=1081.7 m, battery 16%, Landing was triggered due to the Critically Low Battery;
5. T=15-27, h=-33 m, d=1087.3 m, battery 0%, the flight record ended. Please do not fly in high-wind condition.
According to the analysis, the incident was not caused by any product malfunction factors. As such, we could not provide warranty service.

No reason as to why controller disconnected or even mention of it and where I was there was no wind and if there was wind higher above I had no intention of flying high, it did that on it own,

Anyway any help to put this to rest either way is much appreciated. sorry for the long post.

DJI Flight Log Viewer - PhantomHelp.com

DJIFlightRecord_2017-08-10_[17-26-51].txt
 
I viewed your Flight Log first then read your post and my 1st guess was also wind related issue. Seemed like it was struggling to come home for about 2.5 minutes
 
I viewed your Flight Log first then read your post and my 1st guess was also wind related issue. Seemed like it was struggling to come home for about 2.5 minutes
there could be zero wind at ground level but have high wind at higher elevation,i know dji is hard to deal with but the evidence speaks for itself unfortunately.
why the app disconnected can be many factors but using sport mode increases chances of retrieval but even that has limits.,experienced pilots lower their height and zig zag back
this forum has a wealth of knowledge if members would just spend the time and read up and educate beforehand
even so,sorry for your loss.

edit
after reading the log,it never left gps mode and wind did take it,even in sport mode it only did 4-6 mph
 
Last edited:
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According to the flight log, the drone was fighting winds of up to 42.7 km/h at the altitude it was at. The drone not coming home was pilot error.
 
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According to the flight log, the drone was fighting winds of up to 42.7 km/h at the altitude it was at. The drone not coming home was pilot error.
this is why ive chosen to wait till im well versed on most case scenarios before i fly,,by march i may be ready,but i can understand being anxious to fly
 
I'm afraid that DJI is correct in this case. The winds aloft were over 20 mph out of the north, as can be seen if you look at the relationship between pitch/roll and aircraft velocity:

DJIFlightRecord_2017-08-10_[17-26-51]_01.png

Look, particularly, at the period from 650 s to 750 s. The aircraft heading was 328°, pointing back towards the homepoint. The aircraft was at full forwards pitch (25°) but still being pushed backwards at an average of 2 m/s. There is no way that the aircraft could have made it back against that headwind. Note that you did get multiple high wind warnings, so this should not be a surprise.
 
@700 feet altitude,no evidence of attempted descent which would likely have saved the craft
 
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Recently had a flight where there was hardly any wind on ground level but high wind at elevation. UAV app said it wasn't good to fly but I thought I'd try it anyway. Nearly lost the drone! Started to drift, controller input didn't move the drone at all. Luckily I had read about lowering altitude in these situations and that's probably what saved my drone.
 
Not easy to do in a panic, but changing altitude can help.
Wind speed and direction will change at different altitudes, this is how balloons navigate.
 
Yup, never user error. who in his right mind would test fly new equipment over the ocean, and think that there aren't different winds aloft. I always check the UAV app for winds aloft before I fly,
 
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Thank You so much for all your replies and investigation. My instinct was to lower altitude but i had lost line of sight and feed on the screen and felt the panic! Should of decended blindly. It is clear that wind was too strong than I am the idiot here and should of been smart enough to know that ground wind doesn't equal sky wind and checked with the UAV app before flying so expensive mistake, thanks so much for putting it to rest for me
 
I recently lost my mavic but not for the same reason. but one thing I realize now it that when you do a rth the mavic should go into sport mode giving you the best chance of getting home. if the wind is 20 mph or more you'll never get home without sport mode. from what you said you never tried to go into sport mode and fly home manually. that might of made a difference. dji should change the rth so it automatically goes into sport mode. if your rth altitude is set properly you won't hit anything. steve
 
Thank You so much for all your replies and investigation. My instinct was to lower altitude but i had lost line of sight and feed on the screen and felt the panic! Should of decended blindly. It is clear that wind was too strong than I am the idiot here and should of been smart enough to know that ground wind doesn't equal sky wind and checked with the UAV app before flying so expensive mistake, thanks so much for putting it to rest for me
It still does not address the disconnect problem that many people are having! This includes me too.
 
It still does not address the disconnect problem that many people are having! This includes me too.
I can probably explain that. Reading the signal data, it rapidly deteriorated the moment he passed that lighthouse. That lighthouse was likely a strong source of interference.
 
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I can probably explain that. Reading the signal data, it rapidly deteriorated the moment he passed that lighthouse. That lighthouse was likely a strong source of interference.
^That, and - the logs had several disconnects/reconnects always followed by the same message that the OP's SD card is not fast enough for 4K video. The Mavic's video system shares the camera data with the video transmission stream. If there's a problem with the SD card, this could also affect the transmission of video back to the controller.
 
Thank You so much for all your replies and investigation. My instinct was to lower altitude but i had lost line of sight and feed on the screen and felt the panic! Should of decended blindly. It is clear that wind was too strong than I am the idiot here and should of been smart enough to know that ground wind doesn't equal sky wind and checked with the UAV app before flying so expensive mistake, thanks so much for putting it to rest for me
Sorry for your loss. I know it is very frustrating.
 
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^That, and - the logs had several disconnects/reconnects always followed by the same message that the OP's SD card is not fast enough for 4K video. The Mavic's video system shares the camera data with the video transmission stream. If there's a problem with the SD card, this could also affect the transmission of video back to the controller.
Flying at low definition reduces bandwidth.
 
Still, having an insufficient SD card apparently causes data drops.
Whenever I've experienced issues with the SD card, I've just stopped recording and it seems to rectify before anything bad happens. But I almost never record in 4k. I only do that in short bursts as I don't want such huge video files and I'm one of the lucky ones who hasn't had any quality issues with my camera.
 
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^That, and - the logs had several disconnects/reconnects always followed by the same message that the OP's SD card is not fast enough for 4K video. The Mavic's video system shares the camera data with the video transmission stream. If there's a problem with the SD card, this could also affect the transmission of video back to the controller.
To add on to that, the connection stability is total crap if there is a problem with the SD. I speak from experience here when I thought my Mavic had some sort of system failure happening. I once lost all video transmission, with a decoder error, and only got 200m of range before I lost connection to my drone. No matter what I did, it would not work. DJI said my IMU is out of calibration, as if that makes any sense, and I should recalibrate it. According to the rep, it's the brain of the drone. o_O:rolleyes: Well I already did that, and still nothing. They wanted me to send the drone back as it was defective. That wasn't happening either. I came to a realization that the problems started after I returned the drone's SD card back into the memory slot after using it with the Goggles. I reformatted the card on a whim and miraculously, the drone was back to the same reliable self again. Point of this, if the SD card has some kind of problem it can really mess with the drone's systems. I'm guessing it's used as some kind of additional RAM storage when it exists.
 
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