Disconnected in flight - Mavic 2 Pro gone

[RedBird2020]

In email conversations I had with DJI service center addressing the issue as to why I was not able to record or find the yyyy-mm-dd_hh-mm-ss_FLYxxx.DAT files in the folder FlightRecords/MCDatFlightRecords using iTunes to download them, DJI’s response back from DJI Engineers reads and I quote – “This is normal. In order to take up less space, the flightlog of the Mavic 2 was optimized. DJI has not provided official viewing software of DAT files for Mavic 2. If you have any questions, it’s is recommended to supply a DAT file and we will provide the analysis results.”

Tried to explain to DJI that I was not looking in FlightLogs folder but FlightRecords then in MCDatFlightRecords folder. DJI would not respond to or explain why the *FLYxxx.DAT files were missing. Repeatedly asked the same question without any DJI response.

When I asked why so many others on the forums who own a Mavic 2 Pro or Zoom are able to record and access those files, I got no response at all.

I owned a Mavic Air before moving to a Mavic 2 Pro and had no problem recording those files for the Mavic Air.

 

[RedBird2020]

For those who are lucky enough to own a Mavic 2 Pro and record/access those files, FANTASTIC. I’m under the impression that the disappearance of the *FLYxxx.DAT files will become more and more prevalent as time goes on.

For reference, My first Mavic 2 Pro was manufacture on 18 December 2018, my replacement Mavic 2 Pro was manufactured on 27 December 2018 (and it will not record the *.DAT files either) if a correlation can be drawn to exactly when DJI took away recording *.DAT files on iPads/iPhones/Androids.

What does that mean if you are not able to recover your drone after a mishap? Looks like you have less flexibility to establish or understand fault and are much more dependent on DJI’s evaluation/opinion. Now, DJI does not have to argue with you as to the fault/responsibility if you have no clue as to what may have been the underlying cause. That’s not good for customer relations but it can be a great advantage for a manufacture’s financial bottom line.

Without competition from other manufactures who can compete head to head with DJI, it will not swing in favor of the consumer.

Whether you like it or not, that is where the drone industry is and what you as a consumer will have to except or switch to another hobby.

DJI is still levels above other competitors in the drone industry, in capability, quality, reliability, features, etc.

 

[msinger]

For those who are lucky enough to own a Mavic 2 Pro and record/access those files, FANTASTIC. I’m under the impression that the disappearance of the *FLYxxx.DAT files will become more and more prevalent as time goes on.

I've only seen them disappear after syncing my flight logs in DJI GO.

 

[JAW]

You got them to offer a 50% discount so, were it me, I'd put on my negotiating cap and try to get them to include a Care Refresh package.

It appears, however, that you are done with DJI and have gone the merchantability route through VISA. One thing I would do is make sure you ask VISA to provide you with copies of all correspondence received from DJI.

Good luck and please keep us posted.

 

[worldtraveller]

Still in contact with DJI, they have now increased their offer to a 60% discount off the cost of a new Mavic 2 Pro. But that is not going to make any difference because it was their drone/RC which was faulty. And also their software failed to record the .DAT files which they are now trying to use as an excuse for not offering a replacement.

I have already contacted the retailer about the problems, so I may have to dispute the credit card charge. I think that there IS enough evidence to show that the drone failed. And a new (less than 6 week old) drone should not fail like that one did. And I am not the only one to have a disconnection and a failure to return-to-home.

 

[Meta4]

I think that there IS enough evidence to show that the drone failed.

No evidence = enough evidence??

And I am not the only one to have a disconnection and a failure to return-to-home.

I don't know how to put this any clearer.
You didn't have a disconnection and fail to return home.
Your drone almost certainly lost power and fell.
Once it loses power, the connection is gone - it's a symptom and not the cause.
And once it's lost power.. returning to home is no longer an option.

 

[worldtraveller]

Well if the connection is gone then that is a disconnection !!

A drone that is less than 6 weeks old should not just fail as that one did. And the comments in posts 41 & 42 about the lack of .DAT files in recent Mavic 2 models is also very interesting reading. Very convenient for DJI to say that there is no evidence if they have deliberately stopped the Mavic 2s from recording .DAT files. It was nothing that I had changed in the settings as the mobile phone did have .DAT files from the Mavic 1. Only the drone had changed (Mavic Pro to Mavic 2 Pro) using the same phone/same DJI Go app.

When I read about other people have extremely similar experiences (including disconnections over water and also a failure to return-to-home) then I start to think that there IS a problem with some DJI Mavic 2s, their remote controllers or their software.

When it is over 1400 euros then I intend to resolve the matter.

 

[Mega Man]

With all due respect and To play devil's advocate, your wrong, flat out wrong. There are these things called accidents, and mistakes. They happen, to people who have done stuff for years, to newcomers, and old comers. It happens, quite often, ( example : cars )
Dji is not in business to lose monies. Period.

Frankly, I think they have been overly nice. Far more then I would have.

While it sucks, you should learn your drone, for an extended period of time, and iirc in UK you need to keep your drone in los (I can't verify these as I don't live in the uk The law has changed: here's what you need to know before you fly a drone in the UK rule 1, line of sight ) that makes it your fault, if it fell into a lake. Again, your fault, everything has risks and rewards. You took your risk, and expect someone else to eat the consequences.... pretty sad.

For All we know, someone shot it out of the sky with a shot gun, it's happened before....

 

[worldtraveller]

With all due respect and To play devil's advocate, your wrong, flat out wrong. There are these things called accidents, and mistakes. They happen, to people who have done stuff for years, to newcomers, and old comers. It happens, quite often, ( example : cars )
Dji is not in business to lose monies. Period.

Frankly, I think they have been overly nice. Far more then I would have.

While it sucks, you should learn your drone, for an extended period of time, and iirc in UK you need to keep your drone in los (I can't verify these as I don't live in the uk The law has changed: here's what you need to know before you fly a drone in the UK rule 1, line of sight ) that makes it your fault, if it fell into a lake. Again, your fault, everything has risks and rewards. You took your risk, and expect someone else to eat the consequences.... pretty sad.

For All we know, someone shot it out of the sky with a shot gun, it's happened before....

Thanks for your comments, but (of course) I disagree totally with what you say. For one thing, the drone was being flown normally and was well within the published range (at around 800m). It was also line-of-sight (over a lake) and with no obstructions or power lines etc. in the way. So it was well within range and was flown within limits, battery fully charged to start (72% at the time of loss). RC was also near fully charged too. The .txt and .csv files show nothing unusual up to the point of disconnection. Also there have been other people reporting exactly the same problem (disconnection and failure to return-to-home).

If I had made a mistake then I would fully accept that I was wrong and had caused the disconnection, but in this case I did not. The drone disconnected. Something caused it to suddenly stop working and also not to return-to-home. That something was not myself. The drone, the Remote controller or the software had a problem of some kind (? battery critical error??).

If I buy a faulty product (and DJI products in the past have been known to have problems) then I expect it to work for a reasonable time. Less than 6 weeks is not a reasonable time, which is why I want DJI to replace it. A normal manufacturer WOULD replace an item that was faulty and that had failed in a short time, especially one costing 1400 euros.

So the DJI offers of a 30%, then 50% and now 60% discount off the cost of a new Mavic 2 are not good enough, the product was faulty so should be replaced free of charge.

 

[Meta4]

A normal manufacturer WOULD replace an item that was faulty and that had failed in a short time, especially one costing 1400 euros.

A normal manufacturer would need to see proof that the item was faulty, something you can't provide.
It's all been explained over and over again - and ignored over and over again.

So the DJI offers of a 30%, then 50% and now 60% discount off the cost of a new Mavic 2 are not good enough, the product was faulty so should be replaced free of charge.

if I was you I'd hold off until they offer you 150%.

 

[paulatkin73]

For those who are lucky enough to own a Mavic 2 Pro and record/access those files, FANTASTIC. I’m under the impression that the disappearance of the *FLYxxx.DAT files will become more and more prevalent as time goes on.

For reference, My first Mavic 2 Pro was manufacture on 18 December 2018, my replacement Mavic 2 Pro was manufactured on 27 December 2018 (and it will not record the *.DAT files either) if a correlation can be drawn to exactly when DJI took away recording *.DAT files on iPads/iPhones/Androids.

when you say 'does not record *.DAT' - you mean you do not see it on the device itself? this is not the feature of the drone at all, it is only the GO4 app on the device that does the recording.
when you get drone connected to the DJI assistant and go into logs section - does it show logs in there for the flight you did? if not - it is the issue indeed and needs a resolution from the support.

if drone has logs in there - it means all telemetry works as expected and if the local device does not have files - it may be either an issue with privileges for access, or - that seems to be common - the issue with subsequent upgrades of go4 app on old devices that were used for mavics of the previous generation. so, in that case it may be helpful to do a complete factory reset of the device and try the installation of GO4 app again - with proper dialog for access privileges confirmed.
i have 2 mavics now that are made almost year apart and they record .DAT files just fine on any of devices i have, ipads, androids and smart controller.

 

[RedBird2020]

"when you say 'does not record *.DAT' - you mean you do not see it on the device itself?"

Point taken. Actually, I don't know if the *.DAT files are recorded in the GO 4 APP. All I know is that using iTunes, asking it to save the FlightRecords folder (on iTunes), iTunes then sends that folder via the USB cable to my computer. I'll open up FlightRecords on my laptop and see *.txt files and MCDatFlightRecords folder is empty. MCDatFlightRecords folder is where I expect the *FLYxxx.DAT files to be located.

I can use the program BudWalker wrote and decode the *.txt files into *.csv files. Getting 274 columns of flight, AC, RC, Battery, GPS, etc. info out of the *.txt files. *.txt files are just a subset of the *FLYxxx.DAT files. My Mavic Air, the *FLYxxx.DAT had about 1174 parameters.

That said, All I know is the MCDatFlightRecords is empty on my PC

When I had my Mavic Air, that was the folder its *FLYxxx.DAT files were stored from iTunes.

When I use DJI Assistant 2 (for Mavic 2 systems), I see and can download the *.DAT files. Typically in the large MB or GB size range. The onboard drone *.DAT files for Mavic 2 are encrypted so that does not get me anywhere except to know that the drone is collecting and recording all that info on board.

 

[Mega Man]

He doesn't have the drone, he flew it over a lake, it died, and is presumably at the bottom of the lake

 

[RedBird2020]

What I have not done is see what the GO 4 APP in iTunes is reporting for folder size for the FlightRecords folder and then compare that (GO 4 APP) reported size to what I end up with on my PC once the download is complete. If all the *.txt files don't come close to adding up once downloaded to the PC, that indicates there is other data on iPad in the GO 4 APP that I'm just not getting.

 

[paulatkin73]

What I have not done is see what the GO 4 APP in iTunes is reporting for folder size for the FlightRecords folder and then compare that (GO 4 APP) reported size to what I end up with on my PC once the download is complete. If all the *.txt files don't come close to adding up once downloaded to the PC, that indicates there is other data on iPad in the GO 4 APP that I'm just not getting.

i see now, ok, it is odd, like i said - the factory reset could have helped it, perhaps. i did not have such an issue with my ipad, so, cannot speculate on the reason why there weer no files in there.

 

[ea4eob]

I have been many sudden disconnectons with my mavic2P, every times the M2P init RTH and I could restore the link with the Mavic.
Last problem was worst. I had a problem catching GPS satellites at a completly open place. After some rebooting controles and M2P it catch 15 GPS sat and fly all ok...
The next day, i turn on the M2P and the RC, the set all in OK with 18 GPS sats, Antoni init the fly over my vertical close to the sea line. When the M2P is above 100m height, then the RC lose signal and the display indícame connecting...
My worst nightmre happened... The M2P fly to the sea about 10 mts... and starts down directly into the sea... then I turn off and on the RC and connect and is isndicatting... landing... (no near GEO zone)

I think the problem was the sudden disconnection and the GPS sat signal lose at same time, the the M2P cannot return to home because it has not GPS location, and init a vertical landing, if you don't have control over the M2P you have a problem...

I don't like the M2P, every time I fly this dron I don't know the moment to have a control problem...

DJI says me update the M2P and calíbrate compass... Perhaps the next problem will be to lose my M2P and not only the conection... will can be more serious If cause an accident because uncontrol from M2P...

 

[Mossiback]

...DJI says me update the M2P and calíbrate compass...

Calibrate the IMU. My MP was taking a longer and longer time to establish GPS and update the homepoint but after IMU calibration the homepoint is updated within seconds of startup. May not be valid for the M2P but worth a try.

 

[Meta4]

Calibrate the IMU. My MP was taking a longer and longer time to establish GPS and update the homepoint but after IMU calibration the homepoint is updated within seconds of startup. May not be valid for the M2P but worth a try.

IMU calibration is completely unrelated to time to acquire GPS.
What you observed will be a coincidence as the GPS receiver is an independent device.

 

[Mossiback]

IMU calibration is completely unrelated to time to acquire GPS.
What you observed will be a coincidence as the GPS receiver is an independent device.

Perhaps I worded it incorrectly. My MP would show enough satellites to establish the home point but it would take sometimes over a minute to actually do it. After calibrating the IMU it would establish the home point within seconds.

 

[Meta4]

Perhaps I worded it incorrectly. My MP would show enough satellites to establish the home point but it would take sometimes over a minute to actually do it. After calibrating the IMU it would establish the home point within seconds.

Recalibrating the IMU made no difference.
It couldn't have because the GPS receiver does not get any other data from the drone.
It's completely independent.
What you describe is completely normal and sounds like the difference between a GPS "cold start" and "warm start".