Hello,

I have already sent my drone to DJI and they answerd me that they cant find the DATA... today i found the flight log.. as you can see it has no landing... my air lost connection and probably fall over 25 meters.. is that normal that the flight log havent have landing?
and what is that message?  "Downlink Restored (after 0m 1.1s)"

http://www.phantomhelp.com/logviewer/WZ1ATT9WRBV0RIUND8IE/




Thanks..

Sorry for your crash! Downlink restored means that you had lost connection and it gives the timespan. The reason why your flightrecord suddenly stops can either be another connection loss until the crash or the AC having shut off (were there birds around, or other obstacles?). Or did your GO 4 or mobile stop working? Have you checked the cached video on your mobile? Maybe this can provide an explanation about what has happened.

Wachtberger Posted at 2018-3-12 00:39
Sorry for your crash! Downlink restored means that you had lost connection and it gives the timespan. The reason why your flightrecord suddenly stops can either be another connection loss until the crash or the AC having shut off (were there birds around, or other obstacles?). Or did your GO 4 or mobile stop working? Have you checked the cached video on your mobile? Maybe this can provide an explanation about what has happened.

my screen on the phone got frozen and black and white with a message on upper left aircraft disconected, then normaly the window had poped out and i slide it for a homepoint return... 2 minutes never got back so i had go after it and found it down on mud.
*no chace video i didnt recording at that time..

What phone/ tablet are you using?

I was having that issue regularly where it dropped out on my older phone. Have since upgraded and not had any issues.

MavicRich Posted at 2018-3-12 00:49
What phone/ tablet are you using?

I was having that issue regularly where it dropped out on my older phone. Have since upgraded and not had any issues.

S8+  iand its brand new... i dont think that was the issue..

MavicRich Posted at 2018-3-12 00:49
What phone/ tablet are you using?

I was having that issue regularly where it dropped out on my older phone. Have since upgraded and not had any issues.

and the drone as long as it lost signal, it should come at the homepoint.....not crush on its own..

MavicRich Posted at 2018-3-12 00:49
What phone/ tablet are you using?

I was having that issue regularly where it dropped out on my older phone. Have since upgraded and not had any issues.

and when you said i was having that issue regurarly you mean your drone fall down on every signal disconnection? cause thats what happend here... it disconected and never returned or at least stay on air at the pont that it lost the signal..   and dji saying that they cant find the data ...

AndrewGR Posted at 2018-3-12 00:57
and when you said i was having that issue regurarly you mean your drone fall down on every signal disconnection? cause thats what happend here... it disconected and never returned or at least stay on air at the pont that it lost the signal..   and dji saying that they cant find the data ...

Sorry should have been clearer.

I'm now using an S8 and had no issues.

When I had issues the App crashed, screen went blank, had to restart. Thankfully always fly line of sight so guided it back in or waited until the App restarted.

The drone would always hover in place unless the wind was so strong it pushed it. That was my old Phantom. Not had any issues recently like i said.

MavicRich Posted at 2018-3-12 01:01
Sorry should have been clearer.

I'm now using an S8 and had no issues.

it was on sight and thats why i found it.. but it fall down exacly where it lost conection... like it had shut down and then turned on again... like a restart on air.. i dont know hwat to say... scary to think that, restart on air...

AndrewGR Posted at 2018-3-12 00:43
my screen on the phone got frozen and black and white with a message on upper left aircraft disconected, then normaly the window had poped out and i slide it for a homepoint return... 2 minutes never got back so i had go after it and found it down on mud.
*no chace video i didnt recording at that time..

Now I have spotted the potential cause after looking at your flightrecord again. From take off time your battery had significant cell deviations. Deviations should not exceed 0.001V, yours were partly excessively higher. Apparently the battery was defective and shut off at the time when the flightrecord stops.
Have you sent the record to DJI already? If not, do so and tell them about the cell deviations.
P.S. I recommend making it part of the pre-flight checks to also check the battery data in GO 4 before taking off. With such deviations it would be a "no go".
Edit: Please ignore this post, my statement above is wrong.

Wachtberger Posted at 2018-3-12 01:10
Now I have spotted the potential cause after looking at your flightrecord again. From take off time your battery had significant cell deviations. Deviations should not exceed 0.001V, yours were partly excessively higher. Apparently the battery was defective and shut off at the time when the flightrecord stops.
Have you sent the record to DJI already? If not, do so and tell them about the cell deviations.
P.S. I recommend making it part of the pre-flight checks to also check the battery data in GO 4 before taking off. With such deviations it would be a "no go".

look at this deviations of this flight..   i mean its so much different?
and this its in my responsibility?  i have the precheck list app but it didint saw anything..

http://www.phantomhelp.com/logviewer/QCAKN6I6LO4AMV3X7LRO/

AndrewGR Posted at 2018-3-12 01:21
look at this deviations of this flight..   i mean its so much different?
and this its in my responsibility?  i have the precheck list app but it didint saw anything..

The small cell deviations you have on your battery mean nothing. I suppose that either the quad to battery connection has been broken or the electronics in the battery for some unknown  reason have shut down the battery. Why I can not look out of your log.

You need to get in the airplane's log with DJI Assistant2 for more information.

Regards Leif.

Landbo Posted at 2018-3-12 01:57
The small cell deviations you have on your battery mean nothing. I suppose that either the quad to battery connection has been broken or the electronics in the battery for some unknown  reason have shut down the battery. Why I can not look out of your log.

You need to get in the airplane's log with DJI Assistant2 for more information.

Dji just contact me and they said that they found the logs.... it is being investigate right now and they will get back to me with the results.. the damage from the fall  is estimated at 200 euros.
i didnt do anything wrnog so i am going after warranty.
thanks for the response guys.

AndrewGR Posted at 2018-3-12 01:21
look at this deviations of this flight..   i mean its so much different?
and this its in my responsibility?  i have the precheck list app but it didint saw anything..

I was wrong, sorry, the maximum acceptable deviation is 1V not what I have written. And I have never said that battery deviation was your fault.
Edit: I was again wrong, please ignore. Deviation should be below 0.1V.

AndrewGR Posted at 2018-3-12 02:05
Dji just contact me and they said that they found the logs.... it is being investigate right now and they will get back to me with the results.. the damage from the fall  is estimated at 200 euros.
i didnt do anything wrnog so i am going after warranty.
thanks for the response guys.

I wish you good luck!

Wachtberger Posted at 2018-3-12 02:11
I was wrong, sorry, the maximum acceptable deviation is 1V not what I have written. And I have never said that battery deviation was your fault.

i didnt say that you said that mate, i just asked cause i seriously dont know.
and if its a MUST, or an option to check the battery before flight.

Thanks.

AndrewGR Posted at 2018-3-12 02:13
i didnt say that you said that mate, i just asked cause i seriously dont know.
and if its a MUST, or an option to check the battery before flight.

Then all is well. In order to ensure secure flight I would say checking the battery is important although I believe the majority don't do it.

AndrewGR Posted at 2018-3-12 02:05
Dji just contact me and they said that they found the logs.... it is being investigate right now and they will get back to me with the results.. the damage from the fall  is estimated at 200 euros.
i didnt do anything wrnog so i am going after warranty.
thanks for the response guys.

It's good news. A new drone should also be able to keep itself in the air and land where the pilot expects it to land.

Fingers crossed for DJI is finding an error on the machine.

Regards Leif.

Wachtberger Posted at 2018-3-12 02:11
I was wrong, sorry, the maximum acceptable deviation is 1V not what I have written. And I have never said that battery deviation was your fault.

Sorry, but this totally wrong! Maximum deviation for LiPo battery cells should not exceed 0.07 V.

Landbo Posted at 2018-3-12 02:26
It's good news. A new drone should also be able to keep itself in the air and land where the pilot expects it to land.

Fingers crossed for DJI finding an error on the machine.

Thanks dude! i will post the decision that they will made here.

Keule Posted at 2018-3-12 02:29
Sorry, but this totally wrong! Maximum deviation for LiPo battery cells should not exceed 0.07 V.

You are right.

The battery deviations can be automatically checked in the app, as part of the app’s pre flight checks.  Putting the onus to check this in the pre flight check is sloppy and DJI should take note that the app can check this before allowing the ESC’s to spin the motors.

The code effort is minimal and would remove the number of crashes as a result of bad batteries.  It would also mean that the novice users will be protected against battery issues leading to damage, and keep us flying for longer.

As part of the arming checks, DJI can hard code the values that are an acceptable deviation and prevent takeoff. If a takeoff is still required, an override can be configured with a warning that this will void any warranty coverage  if there is an issue during flight

@DJI Admins, can you pass this onto the engineers for the next app update?

Keule Posted at 2018-3-12 02:29
Sorry, but this totally wrong! Maximum deviation for LiPo battery cells should not exceed 0.07 V.

Where I come from, we use to discard a battery if there is more than 0.1 Volt difference between the cells under load. But 0.07 or 0.1 Volt is (almost) the same voltage.

Happy flight, Leif.

PUMMY Posted at 2018-3-12 02:42
The battery deviations can be automatically checked in the app, as part of the app’s pre flight checks.  Putting the onus to check this in the pre flight check is sloppy and DJI should take note that the app can check this before allowing the ESC’s to spin the motors.

The code effort is minimal and would remove the number of crashes as a result of bad batteries.  It would also mean that the novice users will be protected against battery issues leading to damage, and keep us flying for longer.

It is never sloppy to check condition of your battery particularly right before you fly, it takes a very short time and once you get used to doing it, it becomes second nature.
Manned pilots preflight check everything on their aircraft even though on board computers also report findings, they even do it old school way pen and preflight logs.

I do understand that these drones are sold to completely inexperienced people and dji has a duty to make sure that they are safe to fly for those using these aircraft, but it’s just wrong to point out something is sloppy if it’s a safety check, if you are testing for commercial license you are required to check battery data.

hallmark007 Posted at 2018-3-12 02:58
It is never sloppy to check condition of your battery particularly right before you fly, it takes a very short time and once you get used to doing it, it becomes second nature.
Manned pilots preflight check everything on their aircraft even though on board computers also report findings, they even do it old school way pen and preflight logs.

Allow me to explain my “sloppy” comment
(I do realise that automated processes can fail, so this is not lost on me)

The batteries don’t have balancer leads we can plug a smart balancer into and check the battery levels with, you have to navigate the app and access the menu in order to do so.

If this has to be checked in the app, then you can automate this as DJI dictate, in order to ensure battery health before a flight
And if this can be automated, the logs can be included in the flight records as well to provide a record of battery health, maybe even allow pre emptive battery failure detection because we have a history

In the electric glider world, the battery health check could not be automated, but that is not the case here and the point here is to understand why a manual navigation to the settings would provide a safer battery health check than the app doing this, and flagging any conditions that could impact a safe flight

PUMMY Posted at 2018-3-12 03:09
Allow me to explain my “sloppy” comment
(I do realise that automated processes can fail, so this is not lost on me)

I fully agree with you on this matter and your point is well made and should be forwarded to engineers in the hope they might take your good advice.

I’m not to sure this crash has anything to do with battery, this Aircraft may well have hit something that caused it to crash it wasn’t flying that high it was approx 70ft above homepoint but at 1250 ft out what is the terrain like was it going uphill if so then Aircraft would be a lot closer to the ground and could easy find obstacles particularly if OP had lost downlink signal for a period of time. But I suppose we will have to see the outcome from dji.
Hopefully OP gets a warranty.

hallmark007 Posted at 2018-3-12 03:44
I’m not to sure this crash has anything to do with battery, this Aircraft may well have hit something that caused it to crash it wasn’t flying that high it was approx 70ft above homepoint but at 1250 ft out what is the terrain like was it going uphill if so then Aircraft would be a lot closer to the ground and could easy find obstacles particularly if OP had lost downlink signal for a period of time. But I suppose we will have to see the outcome from dji.
Hopefully OP gets a warranty.

i had apas on and all sensors on.. at 25 meters.. the area hasnt have anything higher than 8 maybe 12 meters (trees mostly).  So the aircraft i dont think that hit somthing... and if he had hit something.. a message on the report would appear for sure, i think..

Looking at the logs, is everyone saying that the green line into what looks like a tree is not relevant here?

Street view at that road on the logs should easily tell if the tree is higher than 70ft

PUMMY Posted at 2018-3-12 03:48
Looking at the logs, is everyone saying that the green line into what looks like a tree is not relevant here?

Street view at that road on the logs should easily tell if the tree is higher than 70ft

Remember the tree needs to be higher than 70ft from homepoint.

PUMMY Posted at 2018-3-12 03:48
Looking at the logs, is everyone saying that the green line into what looks like a tree is not relevant here?

Street view at that road on the logs should easily tell if the tree is higher than 70ft

This is the best picture of the place that the accident occured... the trees is no more than 10 meters.. i flew at 24-26 meters.. and i didt saw anything wrnog until the suddenly disconnection and crush.

hallmark007 Posted at 2018-3-12 04:05
Remember the tree needs to be higher than 70ft from homepoint.

So that is easy
Ground Alititude at home point compared to ground alititude at the known point, and check in a 30 metre radius for any objects that contact could be made with.

PUMMY Posted at 2018-3-12 04:13
So that is easy
Ground Alititude at home point compared to ground alititude at the known point, and check in a 30 metre radius for any objects that contact could be made with.

Except you can’t check for other flying objects like birds.

PUMMY Posted at 2018-3-12 04:13
So that is easy
Ground Alititude at home point compared to ground alititude at the known point, and check in a 30 metre radius for any objects that contact could be made with.

as you can see.... and i left the higher vaule that i found.

hallmark007 Posted at 2018-3-12 04:18
Except you can’t check for other flying objects like birds.

if a bird hit it.. a message should have been wroten in the logs, like motor faild, or attitue lost or i dunno what... not just fall down.. after a mysterious disconnection.

And after disconnection the drone should come back at homepoint.. i found it exacly where it got disconected. birds isnt the cause i think.

AndrewGR Posted at 2018-3-12 04:26
if a bird hit it.. a message should have been wroten in the logs, like motor faild, or attitue lost or i dunno what... not just fall down.. after a mysterious disconnection.

And after disconnection the drone should come back at homepoint.. i found it exacly where it got disconected. birds isnt the cause i think.

Once again, have you checked the cached video on your mobile device? Maybe this can give a hint...

AndrewGR Posted at 2018-3-12 04:26
if a bird hit it.. a message should have been wroten in the logs, like motor faild, or attitue lost or i dunno what... not just fall down.. after a mysterious disconnection.

And after disconnection the drone should come back at homepoint.. i found it exacly where it got disconected. birds isnt the cause i think.

You must remember that phantom Help logs lag behind downloading information to your app, this is why in almost every case we see with phantom Help logs end some seconds before crash, I mean have you ever seen a crash on phantom Help logs very few maybe if aircraft gets stuck up a tree and is still powered on.
Your black box data will show up to impact so only this can give you that extra information you need to find out what occurred , I’m not saying it wasn’t a disconnect or battery failure but there is nothing in your log to show it was, so we are all just surmising.

hallmark007 Posted at 2018-3-12 04:36
You must remember that phantom Help logs lag behind downloading information to your app, this is why in almost every case we see with phantom Help logs end some seconds before crash, I mean have you ever seen a crash on phantom Help logs very few maybe if aircraft gets stuck up a tree and is still powered on.
Your black box data will show up to impact so only this can give you that extra information you need to find out what occurred , I’m not saying it wasn’t a disconnect or battery failure but there is nothing in your log to show it was, so we are all just surmising.

yea i know.. and thanks for that.

I jut answerd them to reject those reasons and think of somthing else.

Thanks again.

AndrewGR Posted at 2018-3-12 04:55
yea i know.. and thanks for that.

I jut answerd them to reject those reasons and think of somthing else.

No problem I really hope it works out for you. Good luck

Wachtberger Posted at 2018-3-12 04:35
Once again, have you checked the cached video on your mobile device? Maybe this can give a hint...

Yes I checked.. I don't have any video of that flight it was only 55 secs.