Hi I was flying today evening as soon as I launched from ground within 2 minutes the drone lost the signal and got disappeared.I have synchronized the data on the airdata uav which shows within 2 minutes of launch it lost its signal due to some aircraft issue. As I always initialize wait for home point to update and then fly. Also, I have a DJI Refresh. I have attached my DJI Purchase along with the my flight logs. I everytime check weather, Initialize home point then fly it check satelights.

I received the following response from DJI support which surprises me:

we have finished the data analysis, and the result is as follows:


1. The aircraft worked under GPS mode in the flight;
2. The pilot pushed the pitch stick forward, the aircraft flew forward, then the flight record ended at T=03:41, H=44 m, D=190 m;

Please upload your TXT flight log here and post the link to that page back here.

But what did DJI conclude? Pilot error or software/hardware issue?
Sorry for what happened, I know how you feel.
I also lost my first spark

Flysafely all
Alex

Hi Please find my uploaded data here:

https://www.phantomhelp.com/logviewer/UUH1QNPNP5ARPD9EA2Y5/#

I don't see any pilot error here.

ajrulez Posted at 11-14 13:32
Hi Please find my uploaded data here:

https://www.phantomhelp.com/logviewer/UUH1QNPNP5ARPD9EA2Y5/#

Did you launch from a roof or balcony ?

If above link does not work. Reuploaded here:

http://www.phantomhelp.com/LogViewer/FV1DBO9YA6V3AEUPV3IH/

hallmark007 Posted at 11-14 13:39
Did you launch from a roof or balcony ?

Hi hallmark, I launched it from the Roof. I have flown from here many times.

May be someone in the apartments you flew over took a shot at it when on the other side of the building or a bird hit over the lake. Hard to say other than the clear signal loss.

The security of the marriott hotel said he saw it going in the water. As the GPS coordinates also shows as the location in lake. I dint wanted to jump in as it has snakes and stuff in there.
I will have to hire a professional diver if i need to recover my drone.

A few ideas:

1) The battery shut off and the Mavic dropped like a rock into the water.

2) Or more likely -- you flew the Mavic behind that building (since it was heading in that direction at full elevator), the Mavic attempted to return home, and it crashed into the side of the building or onto a balcony.

hard to say what happened from your log.   on signal loss with no reconnection the drone should attempt to return to home..

few options..

1 is the wind caught it, the wind may been a bit stronger out over the water  and it blew it sideways/off course or lost some altitude..hit a building attempting to RTH..

2. got stuck in a "lag loop" as i call it, your facing 90 degrees of take off position with the drone.. basically over the water facing down stream with throttle maxed out forward, so possible got caught in a lag loop and just kept flying 90 degrees away from you.

3. a bird strike while it no signal ..rare occurrence..but it sometimes happens.

4. hit a building or tree attempting to return. may have missed it normally but it for some reason clipped something.


as for "lag loop", i had my mavic air go into a lag loop the other day, its scary.  happens when on fridge of signal..basically where it accepts the last command over and over and over again.. so if pressing forward full speed the wrong way.. its stuck in that loop it may fly away.. luckily i haven't had it fly away yet, but i have had it get stuck in a loop and fly until lost signal i couldnt correct it.. flew for 1500 feet out of my control and beyond range before something in the drone decided time to RTH..

ajrulez Posted at 11-14 13:39
If above link does not work. Reuploaded here:

http://www.phantomhelp.com/LogViewer/FV1DBO9YA6V3AEUPV3IH/

Your log doesn’t show any pilot error, your signal did drop a few times the area you were flying in looks like it might be prone to that, but you continued on , I’m presuming that it finally lost signal and you believe it never returned.
This could be the case, but do you know what setting you had set for loss of signal, there are 3 RTH , land or hover, if you had it set to the latter 2 then this is what will  happen,
Other than that your log ends early not sure if there is a second log, it would be in your device.
If you had loss of signal set to RTH then your craft would have stopped for 3 seconds, then taken the same route home it just flew, but without further info impossible to say,
Have you gone to last known location to search ?

Great analysis msinger, I wonder why would the battery shut off all of sudden on ~90%.
Thanks for the Red area I will check there again today.

I did initiate the return to home as soon as I saw the signal lost and continuous beep started and also tried to get it higher as there should be no building avoidance as shown below via FRAP:

Your RTH altitude was set to 20 meters, so it most likely crashed into the building if it attempted to return home.

hallmark007 Posted at 11-14 14:04
Your log doesn’t show any pilot error, your signal did drop a few times the area you were flying in looks like it might be prone to that, but you continued on , I’m presuming that it finally lost signal and you believe it never returned.
This could be the case, but do you know what setting you had set for loss of signal, there are 3 RTH , land or hover, if you had it set to the latter 2 then this is what will  happen,
Other than that your log ends early not sure if there is a second log, it would be in your device.

It was set to RTH on RC signal loss.

msinger Posted at 11-14 14:08
Your RTH altitude was set to 20 meters, so it most likely crashed into the building if it attempted to return home.

Why would it descend to 20 metres when it was already at 44 metres, and it supposed to retrace it’s route .

Looks like they take it serious…..

The weather looks great for me no wind issue.

I had set RTH on loss signal.

Where would I get the second log ?

I have DJI care Refresh+ with DJI select member.

I did check at the last know location. Last known shows just above the lake.

Hi Ajay, we're sorry about the loss. I was able to pull up your case with your account here in DJI Forum. Upon checking, the result of the analysis was based on the flight data and records you have provided. The team found no product malfunction after the investigation. However, we received your email disputing the result. The request of re-analysis has been forwarded to the proper team in order to double check the record. We will get back to you once we received the feedback. We hope for your patience.

MarcelN Posted at 11-14 14:41
Looks like they take it serious…..

As in? Sorry I didn't get you.

DJI Diana Posted at 11-14 15:41
Hi Ajay, we're sorry about the loss. I was able to pull up your case with your account here in DJI Forum. Upon checking, the result of the analysis was based on the flight data and records you have provided. The team found no product malfunction after the investigation. However, we received your email disputing the result. The request of re-analysis has been forwarded to the proper team in order to double check the record. We will get back to you once we received the feedback. We hope for your patience.

Thank you Diana for your reply. I appreciate.

Actually, I haven't received any update since 2 days so just wondering what happened. Also the case status shows wrong number.

hallmark007 Posted at 11-14 14:13
Why would it descend to 20 metres when it was already at 44 metres, and it supposed to retrace it’s route .

It wouldn't. DJI drones never descend before returning to the home point.

The OP said he activated RTH. Unfortunately, the aircraft does not retrace its flight path when RTH is manually activated.

And, if he didn't manually activate RTH, I'm still not sure the aircraft would have attempted to retrace the flight path since obstacle avoidance was disabled. I've never tested the retracing feature with obstacle avoidance disabled.

msinger Posted at 11-14 16:06
It wouldn't. DJI drones never descend before returning to the home point.

The OP said he activated RTH. Unfortunately, the aircraft does not retrace its flight path when RTH is manually activated.

I wasn’t aware that OP activated RTH , in his opening post there is no mention of him hitting RTH , also it doesn’t show in his log, His ph log also ends in pgps mode, so I’m confused, or maybe this isn’t the first time he posted, thanks for the info .

msinger Posted at 11-14 16:06
It wouldn't. DJI drones never descend before returning to the home point.

The OP said he activated RTH. Unfortunately, the aircraft does not retrace its flight path when RTH is manually activated.

Ok I see he mentioned after I posted . Sometimes you just can’t win thank you.

ajrulez Posted at 11-14 15:43
Thank you Diana for your reply. I appreciate.

Actually, I haven't received any update since 2 days so just wondering what happened. Also the case status shows wrong number.

Hi ajrulez, I see the email has been replied by the related team and it seems you have accepted the data analysis result and the resolution we provided right? Please let us know if you have any further concern.

Hi Mindy, Yes, I had no other option than to accept the data analysis. But, I have hired a professional scuba diver to retrieve the drone and get the analysis from its black box to see exactly what was the problem and update here.

ajrulez Posted at 11-15 09:17
Hi Mindy, Yes, I had no other option than to accept the data analysis. But, I have hired a professional scuba diver to retrieve the drone and get the analysis from its black box to see exactly what was the problem and update here.

We're really sorry for the loss, Ajrulez. If the drone has been drowned in the water for too long, the data in the black box is possibly corrupted or not retrievable anymore. The analysis team will still rely on the flight record in the app wherein the root cause of the incident can't really be verified as the record just ended without any sign of unit getting faulty.

The process of getting the unit replaced will continue as advised by Dora. Again, we're sorry for the trouble and thank you for your understanding. Hope you'll be back in the air soon!

Thank you Diana. I am waiting for response from your team to reply to be back on air

ajrulez Posted at 11-15 15:47
Thank you Diana. I am waiting for response from your team to reply to be back on air

We've sent a follow up to Dora so the case can be endorsed to the relevant team for the replacement of your Mavic. In case you need further help with the process within the next days, please keep us updated

Thank you Diana

I hope I receive any reply from Dora by tonight. Else i don't want it to delay as its weekend. Also its been a week now since complain lodge.

ajrulez Posted at 11-16 08:42
I hope I receive any reply from Dora by tonight. Else i don't want it to delay as its weekend. Also its been a week now since complain lodge.

Ajrulez, I can see that the Virtual Order for your Mavic's replacement has been processed. Since the unit is out of stock in our Online Store, it will be processed in our facility instead. You'll have the quote soon with the discount applied.

Thank you Diana.  appreciate your help.

ajrulez Posted at 11-16 10:16
Thank you Diana.  appreciate your help.

Hi ajrulez, upon checking the case log, the quotation has been sent to you, please kindly check whether you have received it. If there is any further question, feel free to contact us.

Hi Susan, I did receive the quotation, but It's unfortunate that the quotation was wrong as per promised xx% discount.  I spoke to customer care and asked them to re calculate. They said they will come back to me with new updated one.

I need it asap as i will be traveling international next week due to thanks giving. The more early i need the more is the delay. Since the quotation is changing I requested them to remove battery too. Total is equivalent of new drone only. It's been a week now.

ajrulez Posted at 11-16 21:01
Hi Susan, I did receive the quotation, but It's unfortunate that the quotation was wrong as per promised xx% discount.  I spoke to customer care and asked them to re calculate. They said they will come back to me with new updated one.

I need it asap as i will be traveling international next week due to thanks giving. The more early i need the more is the delay. Since the quotation is changing I requested them to remove battery too. Total is equivalent of new drone only. It's been a week now.

Received with thanks! This has been forwarded to the designated team for double check, we'll keep following up.

Thank you Hopefully I hear back soon.

Is there any possibility to track lost drones ? I am sure we could track down once some one turns it on.

ajrulez Posted at 11-17 09:52
Is there any possibility to track lost drones ? I am sure we could track down once some one turns it on.

I thought it dropped into the water? If so, I doubt anyone else went in after it.

From all analysis it shows it is in water. But what if it fell by side and some one used it ? Can I track it ? Just to make sure it is in water.
Also, I would like to know if some one uses can I check gps location from my app ? Like find my aircraft ? What are the after loss effects ? Just lev it ?