Joerg62 Posted at 2018-2-4 18:48
Sorry, the period after the link screwed it up. Try www.dreamlandresort.com/FLY222.DAT

I tried repeatedly to upload to the link you suggested, but I keep getting a "Connection was reset" error. The page indicates it expects a txt or csv log. So the upload may be choking on the binary file.

That link goes nowhere. For anyone here to look at the flight log, it needs to be decoded, thats why we suggest you go to http://www.phantomhelp.com/LogViewer/Upload/ and follow the instructions there.

Hellsgate Posted at 2018-2-4 19:21
Am downloading txt version will see if i can fix this problem

You go girl!

Ok well downloaded the txt file but cannot upload to the log viewer either file is corrupted or incorrect format for the viewer

Hellsgate Posted at 2018-2-4 19:58
Ok well downloaded the txt file but cannot upload to the log viewer either file is corrupted or incorrect format for the viewer

Well, it seems we are stuck. I do not have the DJI app (txt) or Litchi (csv) log file the upload link expects. Unfortunately I had logging disabled. I do have the .DAT file that I downloaded from the drone, but that requires a 3rd party PC software to extract the various pieces of data into several files. None of them work for the upload link either.

I will just keep trying to get in touch with DJI support. Having been unsuccessful at that so far I guess I was kind of hoping that the moderators might be able to hook me up. Anyway, thank you all for your input and my apologies for the confusion.

I may be wrong but i think the dat file can be read using the dji assistant (Viewer), go to

C:\Program Files (x86)\DJI Product\DJI Assistant 2\Assistant\Viewer.exe

Then browse to your dat file, or someone here can view it that way for you, Labroides perhaps? its a but complicated for me mind lol

Bashy Posted at 2018-2-4 21:16
I may be wrong but i think the dat file can be read using the dji assistant (Viewer), go to

C:\Program Files (x86)\DJI Product\DJI Assistant 2\Assistant\Viewer.exe

Eureka! Success! I can open the .DAT file with the DJI Assistant Viewer. Thank you sir! Now back to my original question: Does anyone who knows how to read the graphs see anything odd going on around 254 seconds into the flight? The data file is located on my server:

www.dreamlandresort.com/FLY222.DAT

Then click "Save File".

I realise that the drone has been broken but do you know if all 4 propellers are still attached, even if they are broken? Another reason could be a failed esc or motor but with using the Litchi app, you may not have seen any previous warning messages if one was failing. Another possibility is a crack in the frame arm underneath just inboard of the motor which seems to originate from the vent. If there was a crack and it had developed significantly then sport mode and sudden manoeuvres may have caused a failure at that point which could have brought your drone down.

Jenee 2 Posted at 2018-2-4 22:19
I realise that the drone has been broken but do you know if all 4 propellers are still attached, even if they are broken? Another reason could be a failed esc or motor but with using the Litchi app, you may not have seen any previous warning messages if one was failing. Another possibility is a crack in the frame arm underneath just inboard of the motor which seems to originate from the vent. If there was a crack and it had developed significantly then sport mode and sudden manoeuvres may have caused a failure at that point which could have brought your drone down.

I found all four hubs, the round centers of the propeller that attach to the motors, still attached or within a couple of feet of the drone. So I doubt the drone lost a propeller. I think all the damage resulted from the crash. I did visually inspect the drone for damage in the morning. Could I have missed a hairline crack? Possibly. But since it never crashed before I am not sure how that would develop.
I was flying straight at my location in a moderate, constant descent. No sudden input at the time of the crash. The more I think about it the more I believe I did not hear the motors at all as it tumbled down. But I can't be sure. I found the battery within a foot of the drone, still on and at about 30%. I believe it was ejected in the crash, not in mid-air. And yes, its a genuine DJI high capacity battery.

Battery stats look really weird to me

thats a bad experience i guess.. but hope u can get the(latest flight Log) *.Txt or CSV Files out from your phone and upload to http://www.phantomhelp.com/LogViewer/Upload/

Extract it out from your handset Folders (u might have to go figure out how ur gonna find it def its inside within..) to your PC and upload as indicate by the webby........hope everyone can get a clear vision soon .

Graph showing the weird battery fluctuations before the current spike and PWM spinning down:

That spike in current could be consistant with a siezed motor.
Have you tried spinning the motors by hand you should feel only a small amount of resistance ?

ESC stands for Electronic Speed Controller. It controls the motor rpm. There are 4 built in, one for each motor. There are either 4 separate PCBs like in the old days(or diy quads), or they are integrated into the mainboard.

That happening should be investigated by DJI. Can a 3rd party App like litchi even control the drone in such a deep degree that it causes a hardware failure? I think the api provided by dji prevents that. There were similar single engine failures with the GO4 App also.

Fox

CraigR Posted at 2018-2-4 23:55
Graph showing the weird battery fluctuations before the current spike and PWM spinning down:

[view_image]

The fluctuations look similar to previous missions. Red is the fatal mission, purple is a mission earlier that day. I believe that spike at the end of the fatal mission, before it sort of "flat-lines" is me switching to Sport mode and speeding away from me, then turning and beginning to come back.

Hellsgate Posted at 2018-2-5 01:12
That spike in current could be consistant with a siezed motor.
Have you tried spinning the motors by hand you should feel only a small amount of resistance ?

Yes, the motors all spin freely.

iFoxRomeo Posted at 2018-2-5 01:31
ESC stands for Electronic Speed Controller. It controls the motor rpm. There are 4 built in, one for each motor. There are either 4 separate PCBs like in the old days(or diy quads), or they are integrated into the mainboard.

That happening should be investigated by DJI. Can a 3rd party App like litchi even control the drone in such a deep degree that it causes a hardware failure? I think the api provided by dji prevents that. There were similar single engine failures with the GO4 App also.

I have tried repeatedly to contact DJI, and also sent them the logs several times. Sadly, so far no response. I don't believe that the Litchi app has anything to do with it. And again, I am not looking for a warranty claim. I just want to understand what happened. I will buy a new drone and I know this crash will be in the back of my mind when I fly it... I sometimes fly missions several miles from my location in difficult terrain. If it would have crashed on one of those missions I would be looking at a rather nasty hike to retrieve it. But the reaction in this forum is reassuring that it likely was a one time fluke.

Joerg62 Posted at 2018-2-4 21:57
Eureka! Success! I can open the .DAT file with the DJI Assistant Viewer. Thank you sir! Now back to my original question: Does anyone who knows how to read the graphs see anything odd going on around 254 seconds into the flight? The data file is located on my server:

www.dreamlandresort.com/FLY222.DAT

Everything looks normal to me, except the log stops without landing.  Given that it is an aircraft log that should not be possible, so if it is still under warrantee then it should be a simple warrantee claim.  Presumably a flight controller fault.

How come you are having problems with contacting DJI, what method are you using and have you tried another method?   Make sure you get it underway before Chinese New Year and the spring holidays!

Nigel_ Posted at 2018-2-5 13:30
Everything looks normal to me, except the log stops without landing.  Given that it is an aircraft log that should not be possible, so if it is still under warrantee then it should be a simple warrantee claim.  Presumably a flight controller fault.

How come you are having problems with contacting DJI, what method are you using and have you tried another method?   Make sure you get it underway before Chinese New Year and the spring holidays!

Thank you for taking a look. That is what it looks like to me. Like someone just pulled the battery in mid air. But I always make sure it is securely attached, and I found it right next to the drone.

By flight controller, do you mean the remote that I use to control it? I'm curious, what makes you think the remote failed? Or are you referring to some component in the drone?

I submitted the log several times using the DJI Assistant software, and also submitted a support request through a form on the dji.com site. I got an automated email back with a request number, but nothing else. That was last week Thursday.

Joerg62 Posted at 2018-2-5 15:28
Thank you for taking a look. That is what it looks like to me. Like someone just pulled the battery in mid air. But I always make sure it is securely attached, and I found it right next to the drone.

By flight controller, do you mean the remote that I use to control it? I'm curious, what makes you think the remote failed? Or are you referring to some component in the drone?

Go to the bottom of this page: https://www.dji.com/support/product/phantom-4-pro
.. and click Online Support.
Start a chat with one of their people to get things started

Joerg62 Posted at 2018-2-5 15:28
Thank you for taking a look. That is what it looks like to me. Like someone just pulled the battery in mid air. But I always make sure it is securely attached, and I found it right next to the drone.

By flight controller, do you mean the remote that I use to control it? I'm curious, what makes you think the remote failed? Or are you referring to some component in the drone?

By flight controller, I meant the thing in the aircraft that monitors the sensors, tells the motors how to keep the aircraft stable and on course, and writes the log file.

If the battery had come out, I suspect the aircraft log would contain that information if DJI look at it in enough detail, I probably haven't looked in enough detail, they can see a lot more detail than I can, but a battery falling out after several minutes in the air might be considered a warrantee issue too.

If it is under warrantee then the easiest is to let DJI analyse the log and report their findings, they will either tell you what you did wrong and offer to repair it, or replace the aircraft.   Sometimes they can't tell what happened but that is almost always when the aircraft has disappeared and there is only the phone log to look at.

If you submitted your request late Thursday then they have only had Friday and Monday to look at it, if they are busy then it may take longer, do make use of the chat to check on progress though.

Labroides Posted at 2018-2-5 16:09
Go to the bottom of this page: https://www.dji.com/support/product/phantom-4-pro
.. and click Online Support.
Start a chat with one of their people to get things started

Thanks for the link. I am in the queue waiting to chat with a support tech. Will keep you all posted on the outcome. Thank you all very much for your kind and knowledgeable advice.

Joerg62 Posted at 2018-2-4 23:44
I found all four hubs, the round centers of the propeller that attach to the motors, still attached or within a couple of feet of the drone. So I doubt the drone lost a propeller. I think all the damage resulted from the crash. I did visually inspect the drone for damage in the morning. Could I have missed a hairline crack? Possibly. But since it never crashed before I am not sure how that would develop.
I was flying straight at my location in a moderate, constant descent. No sudden input at the time of the crash. The more I think about it the more I believe I did not hear the motors at all as it tumbled down. But I can't be sure. I found the battery within a foot of the drone, still on and at about 30%. I believe it was ejected in the crash, not in mid-air. And yes, its a genuine DJI high capacity battery.

The reason I asked about a crack is because a few have been reported in the past and I normally check mine for cracks before each flight. On a recent flight, the drone braked suddenly possibly due to the sun as there were no obstacles, and then continued on, but to me, it just didn't feel right. I ended up landing and noticed quite a severe crack under one of the rear arms. The crack had started from a corner of the vent but then went across the whole bottom of the arm and the crack had actually opened a bit. It was possible to bend the arm slightly because of the crack. I never fly in sport mode or in very turbulent conditions but another flyer at the place I was flying at was of the opinion that the arm could fail.

That sounds pretty concerning. I thought the body was quite sturdy, but if it has manufacturing imperfections cracks could easily develop. In my case I really can't tell due to the extent of the damage. I will send it in to DJI for evaluation. The process seems rather automated and I doubt I will actually be able to speak to a tech to find out what happened. But according to the support chat there is a chance it is a warranty issue.

Joerg62 Posted at 2018-2-6 11:55
That sounds pretty concerning. I thought the body was quite sturdy, but if it has manufacturing imperfections cracks could easily develop. In my case I really can't tell due to the extent of the damage. I will send it in to DJI for evaluation. The process seems rather automated and I doubt I will actually be able to speak to a tech to find out what happened. But according to the support chat there is a chance it is a warranty issue.

If an arm had fallen off then it would be obvious in the log!

I've never heard of an arm falling off anyway, there are a few batches of shells where the plastic seems to have been mixed wrong resulting in them cracking, but the cracks always become obvious long before there is a structural failure.

Hi Joerg, I'm so sorry to read your post. The data analysis is based on the flight records in DJI GO and flight log in the aircraft. As long as the flight log has not been overwritten, our engineers can analyze the exact status. May I know how did you contact our support? Email or Online Chat? Please kindly offer your ticket number or phone number, I'd like to help.

Thank you for following up. I originally submitted the case on Feb 1 to us.support@dji.com. I received an automated reply stating my request #970358 and that I would be contacted. No contact so far. I submitted the drone logs several times using DJI Assistant 2. No reply. I then followed the advice of a forum poster and contacted support via chat. I was assigned the case #CAS-1457106-F6P5M1 and I was told I had to send the drone back before warranty eligibility could be determined. I was hoping that the logs could be analyzed before I incur the cost of sending the drone in and the $65 an hour for diagnosis that the fine print mentions. If you read this thread it should be fairly obvious that something very odd happened. I really only want to know what happened so I can avoid a repeat when I buy a new drone. Thanks again.

Nigel_ Posted at 2018-2-6 13:17
If an arm had fallen off then it would be obvious in the log!

I've never heard of an arm falling off anyway, there are a few batches of shells where the plastic seems to have been mixed wrong resulting in them cracking, but the cracks always become obvious long before there is a structural failure.

It would not be an arm falling off. The crack is not hairline and it is just inboard of the motor so if it failed, the motor, prop and very end of the arm  would still hang by the wires. The sensors would detect that something catastrophic had happened, and shut everything down.

Jenee 2 Posted at 2018-2-6 23:59
It would not be an arm falling off. The crack is not hairline and it is just inboard of the motor so if it failed, the motor, prop and very end of the arm  would still hang by the wires. The sensors would detect that something catastrophic had happened, and shut everything down.

The cracks appear in various places, so yes, you could end up with just the motor falling off, however I've never heard of that happening, I don't think it is something worth worrying about.   I suspect that when they build a set of drones with faulty lower shell halves, they never use upper shell halves made from the same batch of plastic and thus the cracks only affect half the shell and you notice them as serious long before the other half of the shell gives up due to the extra load.

DJI Susan Posted at 2018-2-6 19:46
Hi Joerg, I'm so sorry to read your post. The data analysis is based on the flight records in DJI GO and flight log in the aircraft. As long as the flight log has not been overwritten, our engineers can analyze the exact status. May I know how did you contact our support? Email or Online Chat? Please kindly offer your ticket number or phone number, I'd like to help.

So I sent in the drone for warranty repairs last week. Finally received an email stating it was not covered (although support previously assured me the drone was still under warranty and this was clearly a product malfunction). The invoice is for $282 in repairs. I can't get any explanation why the warranty claim has been denied. I am currently in the chat (again!) with support but getting nowhere.

Frankly, dji support leaves much to be desired. I should have gone with my original plan and just bought a new drone. Unfortunately there are no real alternatives to the Phantom 4 Pro for what I am doing.

Joerg62 Posted at 2018-2-14 12:13
So I sent in the drone for warranty repairs last week. Finally received an email stating it was not covered (although support previously assured me the drone was still under warranty and this was clearly a product malfunction). The invoice is for $282 in repairs. I can't get any explanation why the warranty claim has been denied. I am currently in the chat (again!) with support but getting nowhere.

Frankly, dji support leaves much to be desired. I should have gone with my original plan and just bought a new drone. Unfortunately there are no real alternatives to the Phantom 4 Pro for what I am doing.

Hi, there. The case was escalated to the designated department for further check. Please wait patiently, we will have someone contact you and solve the problem. Thanks for your support.

DJI Elektra Posted at 2018-2-21 02:06
Hi, there. The case was escalated to the designated department for further check. Please wait patiently, we will have someone contact you and solve the problem. Thanks for your support.

As someone in this forum predicted, I received an email this morning saying that my warranty claim was denied because I used the Litchi app. Here is my reply:

So, are you saying the warranty claim is being denied because I was using the Litchi app? Litchi uses the DJI SDK. So, is your SDK unsafe to use? I did email you logs of your SDK, including for the flight that ended in the fatal crash. From the logs in the drone you can see that it shut down in mid-air. How can that be the fault of the app used to control the drone?

DJI Elektra Posted at 2018-2-21 02:06
Hi, there. The case was escalated to the designated department for further check. Please wait patiently, we will have someone contact you and solve the problem. Thanks for your support.

Below is the reply from DJI. Bottom line, they say if you use Litchi you are not covered under warranty. This is ridiculous and IMHO a legally unsustainable position! Time to take a long hard look at the competition.

"Unforunately that is correct. Even if Litchi app is using DJI SDK. It is a third party app.  When using third party app such as Litchi, we can not guarantee that it will be able to use the full function and feature of the app, remote control and the drone. It is possible that it could send wrong data that could cause error and malfunction on your remote control and drone. It is advisable to use our recommended app which is the DJI Go 4 app for the Phantom 4 Pro.

We offer DJI SDK to developers for them to create a custom mobile app to maximize the potential of DJI aerial Platform. The goal is allow the opportunity to developers to experience the knowledge and understanding required to create the application using DJI's technology."

Joerg62 Posted at 2018-2-21 11:07
Below is the reply from DJI. Bottom line, they say if you use Litchi you are not covered under warranty. This is ridiculous and IMHO a legally unsustainable position! Time to take a long hard look at the competition.

"Unforunately that is correct. Even if Litchi app is using DJI SDK. It is a third party app.  When using third party app such as Litchi, we can not guarantee that it will be able to use the full function and feature of the app, remote control and the drone. It is possible that it could send wrong data that could cause error and malfunction on your remote control and drone. It is advisable to use our recommended app which is the DJI Go 4 app for the Phantom 4 Pro.

Joerg, it seems that there is some misunderstanding between us. Yes, we do not support to analyze the flight records in the third party app, but our engineers are trying to retrieve the data from the damaged aircraft to see whether it can be analyzed. We'll keep follow up and update as well.

DJI Susan Posted at 2018-2-22 00:30
Joerg, it seems that there is some misunderstanding between us. Yes, we do not support to analyze the flight records in the third party app, but our engineers are trying to retrieve the data from the damaged aircraft to see whether it can be analyzed. We'll keep follow up and update as well.

Funny, I received a late payment notice yesterday for the $282 for the repair, as well as two more invoices for $282 this morning. I paid yesterday after receiving the late notice. I need the drone back in two weeks for a gig and frankly at this point my patience has run out. I paid for the repair, fix my drone and send it back.

Joerg62 Posted at 2018-2-22 08:29
Funny, I received a late payment notice yesterday for the $282 for the repair, as well as two more invoices for $282 this morning. I paid yesterday after receiving the late notice. I need the drone back in two weeks for a gig and frankly at this point my patience has run out. I paid for the repair, fix my drone and send it back.

For the record: After my previous post I just received a phone call stating that the drone would be repaired under warranty. I was not given a reason or a cause for the accident.

A piece of advice: With more personal tech support this could have been handled a lot better.

Joerg62 Posted at 2018-2-22 08:40
For the record: After my previous post I just received a phone call stating that the drone would be repaired under warranty. I was not given a reason or a cause for the accident.

A piece of advice: With more personal tech support this could have been handled a lot better.

Joerg, I just checked your case and the unit has been shipped. According to the case log, it is a warranty case, and the fees will be refunded. Hope you will receive the package soon.

DJI Susan Posted at 2018-2-25 03:04
Joerg, I just checked your case and the unit has been shipped. According to the case log, it is a warranty case, and the fees will be refunded. Hope you will receive the package soon.

I received the exchange drone yesterday. First test flight seems ok. I got a message that the compass and vision sensors need calibration but I hope that re-calibrating those sensors will fix that. I never really found out what caused the crash. One of the support techs I talked to said something about power fluctuations and a power failure. I remember one of the members here said the same after looking at the logs. Not sure what caused that. The new drone flies fine with the battery used when it crashed. Hopefully it was just a fluke. Thanks all for your replies and to DJI support for making it right.

Joerg62 Posted at 2018-2-28 11:57
I received the exchange drone yesterday. First test flight seems ok. I got a message that the compass and vision sensors need calibration but I hope that re-calibrating those sensors will fix that. I never really found out what caused the crash. One of the support techs I talked to said something about power fluctuations and a power failure. I remember one of the members here said the same after looking at the logs. Not sure what caused that. The new drone flies fine with the battery used when it crashed. Hopefully it was just a fluke. Thanks all for your replies and to DJI support for making it right.

Thanks for keeping us updated. I‘m happy to know you have received the package. Please try to change the place or calibrate compass to see whether it works. We'll be here all the time, feel free to contact us if you encounter any difficulties.

DJI Susan Posted at 2018-3-1 00:42
Thanks for keeping us updated. I‘m happy to know you have received the package. Please try to change the place or calibrate compass to see whether it works. We'll be here all the time, feel free to contact us if you encounter any difficulties.

Thanks again. After calibrating the vision sensors all is well. The drone works perfectly and I had two successful flights with the battery used in the crash.

FWIW, two things I noticed with the old drone (the one that crashed, the new one is fine): I always had a hard time connecting when I first turned it on, particularly outside. Most of the time it would sort of connect on the first try, but response to the controller input was lagging and the green controller light intermittently flashed red. I had to power everything off again and back on. Doing this several times eventually connected properly. And in clockwise turns while focusing on an object in the center of the turn radius the gimbal would sometimes shake visibly. Both of these problems are gone with the new drone. May have been early signs of a problem that led to the fatal accident.

Joerg62 Posted at 2018-3-1 10:23
Thanks again. After calibrating the vision sensors all is well. The drone works perfectly and I had two successful flights with the battery used in the crash.

FWIW, two things I noticed with the old drone (the one that crashed, the new one is fine): I always had a hard time connecting when I first turned it on, particularly outside. Most of the time it would sort of connect on the first try, but response to the controller input was lagging and the green controller light intermittently flashed red. I had to power everything off again and back on. Doing this several times eventually connected properly. And in clockwise turns while focusing on an object in the center of the turn radius the gimbal would sometimes shake visibly. Both of these problems are gone with the new drone. May have been early signs of a problem that led to the fatal accident.

Is the battery has appearance damage after the crash? Basically, I might not think it is a good idea to fly with the battery that had crashed before especially if it might have appearance damage.