In a field flight, in a straight line at a height of 40m and without obstacles, after 10 seconds it indicated a change of base and after about 40 seconds (about 250m distance) it announced a disconnection without reconnecting in the next minutes In the configuration it had RTH in case of disconnection but the drone has not returned.
After about 1 hour we located the drone in a meadow, about 100m ahead of the last coordinates sent to the RC-N1.

The analysis of the video of the flight indicates that the drone stops in the second 49" in the air and remains in the same position for about 21 minutes. Then it turns about 170º and remains fixed for about 50 seconds. Then it tilts the camera 45º and it lasts about 150 seconds, after which it descends until it hits the ground. The video continues until 29 minutes 50 seconds (in fact, they are two consecutive videos that add up to 29'50").
The configuration of the drone confirms RTH in case of disconnection.

I have several questions:

• How do you disconnect without reconnecting at 250m? (in other field flights I have taken it to 1200 m)
• Why does it change base, or point of origin?
• Why doesn't it come back and stay in the air?
• Where does it receive commands to turn or tilt the camera? I understand that the controlled descent is the usual when the battery is low.
  

Thanks

JaumeG

Hi Jaume.

Best to get help/advice/explanation is to share your flightlog for this issue
Use this link > https://www.phantomhelp.com/LogViewer/Upload/
Post the uploaded link on here

If you have a log before and after the disconnect  share both.

If homepoint is changed in flight after few seconds than most likely the HP has not been set at start, so take off without a white GPS icon.But log will tell more....

cheers
JJB

I only have one data log, the link is:
https://www.phantomhelp.com/LogViewer/8S6FSALLQS6QQ05CCPU4
which corresponds to the flight until it was disconnected.
The drone continued to fly in a straight line for another 180m, which is where it stopped in the air and then descended.
I hope you can tell me something.

Thanks

JaumeG

JaumeG Posted at 2-23 10:12
I only have one data log, the link is:
https://www.phantomhelp.com/LogViewer/8S6FSALLQS6QQ05CCPU4
which corresponds to the flight until it was disconnected.

Hi,

Had a look at your log.

You started your flight with a yellow GPS icon, so no HP set before or at takeoff.
In the log you see a #3 for this.

0-1 = RED icon = No GPS lock
2-3 = YELLOW icon = GPS lock but no HP set
4-5 = WHITE icon = GPS lock + HP set.

At 34.1s in flight 3 into 4 so HP set in flight but ofcourse not at your position. (in my chart GPS Q column)

Your RTH setting to RTH but no RTH....as it did hover for many many minutes (97% battery) i think your RC lost connection to your mobile device, not to the aircraft.

In that case it will just hover and hover and finally land bc of low battery. [ oops, wrong ofcourse , low battery initiates a RTH... or bad GPS (as start of the flight, so no RTH ]
If you did not press on the RC the RTH button   or did not give input on the RC  it will do nothing as for the drone there is nothing to worry about.
No warnings in the log wich indicates for an abnormality.As you found the drone somewhere else than the last postion, guess your RC input moved the drone away from that last position, this means that there was connection RC<>drone, but not RC>device as the log stops. (for logging you need connection RC<>device)


I always fly with a screen recording active, great to see that for things i have missed on the screen.


cheers
JJB    [ Charts by FRAP ; the 'best' software for data and visual flightlog analysis (www.jjbfrap.eu) ]

JaumeG, can you mark on a map where you found the drone please ?
I am wondering where this  "in a meadow, about 100m ahead of the last coordinates sent to the RC-N1." was.

Hi there. We're deeply sorry for the incident that happened in your unit. You may consider sending the drone in for a proper diagnosis. You may contact our team at https://www.dji.com/support to start up a ticket case. Also, the warranty can be applied depending on the outcome of the damage assessment including the warranty period of your unit. Thank you for your understanding and support.

Sean-bumble-bee Posted at 2-23 13:05
JaumeG, can you mark on a map where you found the drone please ?
I am wondering where this  "in a meadow, about 100m ahead of the last coordinates sent to the RC-N1." was.

Drone landing site

Dirty Bird Posted at 2-24 06:53
I agree that the drone was likely still connected to the RC & only the video/telemetry feeds were lost.  As it was still connected there would be no RTH.  I am puzzled why it did not engage RTH at low battery?

One thing users need to learn is when the video/telemetry feeds are lost, it doesn't necessarily mean the control signal is severed.  This can be determined by the status lights on the RC.  For an RC-N1, RC-N2, or the remote style of the Mavic Mini, when the connection is broken all the battery LEDs will flash in unison.  For the DJI-RC or DJI-RC2, the pill-shaped first LED will display green when connected & red when the connection is lost.

Hi,

Yeah  your are right....it should RTH at low battery.  my bad. (edit my post to this)
Or, like at start of the flight, GPS signal not that good, bad GPS - no RTH but landing.

cheers
JJB

JaumeG Posted at 2-24 00:13
[view_image]

Drone landing site

Blimey that's some way away.

Thanks, I don't remember exactly when the battery leds started flashing, or if all of them at the same time or just the one on the right. Yes, at one point it beeped at a slow frequency and then the beeps accelerated.
Your guess would also explain the drone turning and the camera changing position, maybe I touched the RC controls while looking for the aircraft.
Thank you very much for your explanation and I will keep it in mind in the future.

Best regards