Hi all,

I was flying my P4P, lost remote control signal for about 10 seconds then regained. It started to return home and then I lost remote control signal again and I never saw it again. Something must have malfunctioned. It had full gps signal (full bars, 20 satellites) but never made it home. Plenty of battery and good weather conditions. Tried searching for it at the last recorded location but I could not find. Is there anything I can do?

Yes .. go to http://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions to upload your flight record.
Come back and post a link to the report it provides and someone may be able to work out from the flight data what the issue was and perhaps even point you toward a likely search area.

That's a shame. I hope the flight LOG data will reveal some insightful info, to help you retrieve it, soon.


RedHotPoker

Labroides Posted at 2017-2-18 00:23
Yes .. go to http://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions to upload your flight record.
Come back and post a link to the report it provides and someone may be able to work out from the flight data what the issue was and perhaps even point you toward a likely search area.

Wouldn't upload to that site but here is a link to the file in my google drive.
https://drive.google.com/drive/f ... X1ZuYlk?usp=sharing

First of all which app where you using?

KevDrones Posted at 2017-2-18 09:28
First of all which app where you using?

DJI Go 4

AlecW Posted at 2017-2-18 09:46
I've lost the signal during a RTH more than once but I know what it is.  I fly a big L to avoid flying over some houses but my RTH route being direct takes a different track.  One house in particular that's about 700 or so feet way kills my signal every time I get anywhere near it.  I've watched the video, it's in RTH mode and continues coming home without a pause during the signal loss.   I've had it happen twice now during a RTH and always get signal back after I pass that house.  I've even flow over there manually and boom, get close to that house and the signal dies.  I've got no clue what he has, maybe an external LOS wifi to his barn or something.  

Anyhow, your drone should have come back home regardless of subsequent signal losses.  Hopefully the logs on your device provide some information.  How high was your RTH setting?

RTH was 30 meters, but I was 170 meters high at the time of signal loss

I had a shipping label to send it in for compass repairs, but I wanted to go through all the troubleshooting steps (recalibrating everything and and seeing if that fixed it) before I sent it in

AlecW Posted at 2017-2-18 10:53
I don't think flying at 170M altitude and far enough away to lose single would be considered troubleshooting.   You need to post the logs to get any help or we are just guessing.

I posted them above

tydoblanko-sp Posted at 2017-2-18 11:13
I posted them above

You should try to put them up on PHANTOMHELP just go to the link and follow the instructions.

AlecW Posted at 2017-2-18 11:28
Wrong type of file.  Follow this link http://www.phantomhelp.com/LogViewer/Upload/  You need to use iTunes to get the file if you are on IOS.

Here is the flight log. Note that this was about the fifth test flight I did. I started by staying close then going further with each flight.

http://healthydrones.com/main?share=FdVieR

tydoblanko-sp Posted at 2017-2-18 12:08
Here is the flight log. Note that this was about the fifth test flight I did. I started by staying close then going further with each flight.

http://healthydrones.com/main?share=FdVieR

Unfortunately Healthydrones is next to useless for investigating an incident.
If you can upload to HD, you can upload to http://www.phantomhelp.com/LogViewer/Upload/

That will provide a display of what was happening for every 1/10th of a second of the flight.
If for some reason, you can't upload, then post your .txt file.
Without this info you won't be getting much help.

Labroides Posted at 2017-2-18 14:06
Unfortunately Healthydrones is next to useless for investigating an incident.
If you can upload to HD, you can upload to http://www.phantomhelp.com/LogViewer/Upload/

http://www.phantomhelp.com/LogViewer/5ZUH1S330BO70INTL7BL/

Here is the link. What happened was I had full bar signal. Then my neighbour drove up to me in his big SUV and blocked the rc signal. I told him to drive out of the way and I got back to full controller signal so I cancelled RTH. Then everything just cut out.

From a quick look at the log file, it appears that it was fairly windy at 575 ft altitude, at the rate it was flying during RTH it was going to take about 21 minutes to get back home.

The puzzling thing is why did you not regain signal at some point as it got closer?  Did you leave the RC on for 30 minutes to give it a chance to get back into range, or did you give up after only 1 minute?
I guess the wind may have increased during the return in which case it may not have made it back.

I'm not completely sure that analysis is correct, maybe someone else can check the data based on this suggestion...

Just noticed your other thread: "Whenever I fly my P4P, it always loses gps signal mid flight."

Seems odd to fly a Phantom with a questionable GPS out to 3.5Km distance, has the GPS been fixed ?

Nigel_ Posted at 2017-2-18 15:55
From a quick look at the log file, it appears that it was fairly windy at 575 ft altitude, at the rate it was flying during RTH it was going to take about 21 minutes to get back home.

The puzzling thing is why did you not regain signal at some point as it got closer?  Did you leave the RC on for 30 minutes to give it a chance to get back into range, or did you give up after only 1 minute?

I left the rc on for about 20 minutes and got a friend to drive me closer to the point it lost signal.

Nigel_ Posted at 2017-2-18 16:28
Just noticed your other thread: "Whenever I fly my P4P, it always loses gps signal mid flight."

Seems odd to fly a Phantom with a questionable GPS out to 3.5Km distance, has the GPS been fixed ?

After completing the troubleshooting steps given to me through the zen desk, it had been flying error free for 5-10 flights. I stayed close by for most of those. Must have been a fluke nothing happened during those.

AlecW Posted at 2017-2-18 16:31
Read post #9 of this thread and look at the spiral at the end of this flight.

I don't see anything wrong with the compass.  There is an odd curve at the end of the GPS track, but it was told to yaw with the control stick while RTH was still in the process of being cancelled so I think it started yawing while it was still slowing down from exiting RTH and that caused the curve, maybe helped by the wind and maybe by lack of visual positioning due to the height.

Good thing it wasn't also told to descend while yawing and cancelling RTH - that would be motors off!  Although at least we would then know where the remains are.

I'm sorry to hear. I would recommend contacting the North American Support team in order to have the flight records reviewed for a potential warranty claim.

Are instances like this covered with the DJI Care?

AlecW Posted at 2017-2-18 13:04
It looks like it lost signal for a while and did start the RTH and then 6 seconds after you got the signal back it was cancelled.  After that it almost looks like it went into a spiral, the sort of spiral you see with a compass problem.

Healthy drone misses a lot of data, that other link is better if you can figure it out how to get a log uploaded I'm sure someone with more knowledge than I should be able to see more info.

"...... went into a spiral"

Is it a possible bird strike? Lost a prop and then spiral to earth!!

From my own personal phantom experiences, I'm guessing that a lot of 'out of line of sight' crashes may be due to bird strikes.

EPT160 Posted at 2017-2-19 23:20
"...... went into a spiral"

Is it a possible bird strike? Lost a prop and then spiral to earth!!

I was able to check the location it would have crashed in. No luck.

tydoblanko-sp Posted at 2017-2-18 14:40
http://www.phantomhelp.com/LogViewer/5ZUH1S330BO70INTL7BL/

Here is the link. What happened was I had full bar signal. Then my neighbour drove up to me in his big SUV and blocked the rc signal. I told him to drive out of the way and I got back to full controller signal so I cancelled RTH. Then everything just cut out.

Wow I've never seen data loss for that long a time.  Several seconds at most.

G        06m 33s        576.4 ft        11,938 ft        Data Loss        Downlink data connection lost for 42.8 seconds

EPT160 Posted at 2017-2-19 23:20
"...... went into a spiral"

Is it a possible bird strike? Lost a prop and then spiral to earth!!

The log shows that it was told to turn for 2 seconds using the yaw stick, I'm fairly sure that is what caused the spiral.  The spiral is also a controlled spiral, not an out of control spin, so doesn't look like a collision anyway.

Seems my wind suggestion was wrong, it just took longer than I would have guessed to stop and then get going again on it's way home so I miscalculated the speed.

I think we have to leave the log analysis to DJI, with evidence of problems in the past that where unresolved I guess there is a reasonable chance of a warrantee replacement.

  

Ultimately DJI will be the final judge here but in my opinion I don’t think your case qualifies as a QA refund. Here’s why:

  

Ignoring the fact that you violated TC guidelines (outlined here), you also fail to understand basic radio practices (outlined in the manual, and the DJI radio best practices tutorial found on youtube).

Your phantom flew out quite a distance (~3.6km) and even if you kept it at maximum altitude (120m), on relatively flat ground the LOS angle between your radio and the aircraft lowered to the point of where your neighbour’s house blocked the link signal (causing the first & the final link disconnect).

  
  

Why the final RTH failed is a mystery; With 78% battery left, and good satellite lock it should have made it back home. However, seeing that you have some history of GPS disconnects, the possibility of a GPS disconnect during RTH can’t be ruled out but it can’t be proven either until you recover the drone (and download the FC logs).

  

Here’s a link to the google map of the RTH path you need to search:

  

https://tinyurl.com/zllzhow

  

  

That’s a lot of land to cover,  get someone else to help you search from above. I would volunteer if I didn’t live on the other side of the country.

  

Sorry for your loss, expensive lesson.

  

Good luck.

  

Spirytus Posted at 2017-2-20 06:59
Ultimately DJI will be the final judge here but in my opinion I don’t think your case qualifies as a QA refund. Here’s why:
  Ignoring the fact that you violated TC guidelines (outlined here), you also fail to understand basic radio practices (outlined in the manual, and the DJI radio best practices tutorial found on youtube).

I walked over to the edge of a field with a few hundred meters of flat land in front of me. It was my neighbors suv driving up to me that made it lose signal. Thanks for the help!

Spirytus Posted at 2017-2-20 06:59
Ultimately DJI will be the final judge here but in my opinion I don’t think your case qualifies as a QA refund. Here’s why:
  Ignoring the fact that you violated TC guidelines (outlined here), you also fail to understand basic radio practices (outlined in the manual, and the DJI radio best practices tutorial found on youtube).

Could this very high Tower have anything to do with it?? Also has a spread of 'guys'.

EPT160 Posted at 2017-2-20 22:57
Could this very high Tower have anything to do with it?? Also has a spread of 'guys'.

Good eye. Would mean a considerable drift west during RTH but it wouldn't hurt to check out the site.

If I was in his shoes:

I would plaster "Lost - Reward" posters along that path and  buy a P4 (or P3) from Best Buy to refly/search the same route from up high (within LOS this time). Just need make sure the local BB will honors the 14 days no questions asked return policy once you're done with the search.

If he still can't find it after the search the only saving grace remaining would be to prove history of GPS disconnects from previous flights (hopefully kept the logs).
P.S. Final note, if you're going to fly beyond LOS invest in a marcopolo tracker or at the very least provide contact - reward information on the bird.

Might have flown through the beam of that large satellite dish to the south west of the tower, looks like it has been seriously fenced off in it's own large compound to stop people getting irradiated and has a large power module next to it so must be a transmitter.  Also appears to be steerable, wonder what it is for?

I had quite a similar issue when I passed in front of a intra-coastal merchant ship. Turns out, HF radio waves (Marine RADAR) plays havoc with control of your aircraft. Nigel_ may have a point to consider with respect to the transmitter to the southwest of your flight path...

EPT160 Posted at 2017-2-20 22:57
Could this very high Tower have anything to do with it?? Also has a spread of 'guys'.

Good eye. However I have had previous phantom drones and have flown on all sides of that tower. Logged 50 + flights around it with no issues.