Lost signal, lost drone

[ballerhe75]

Flew out to a distance of 2,400 feet, Weak Signal notice, turned drone towards home, at 944 feet another Weak Signal notice, connection lost. From the first Weak Signal the drone flew back 1,813 feet, then lost signal. Altitude was increased in hopes of not losing signal. A lot of trees, but drone was high above trees. Lost sight of drone due to trees. Pilot error.

Any ideas for the cause?

 

[Thomas B]

Did you have your drone set to RTH on controller signal loss?
What was your altitude before RTH, especially in relationship to the trees you mention?

Also noticed you took off at 44% battery... not much time.

 

[sar104]

Flew out to a distance of 2,400 feet, Weak Signal notice, turned drone towards home, at 944 feet another Weak Signal notice, connection lost. From the first Weak Signal the drone flew back 1,813 feet, then lost signal. Altitude was increased in hopes of not losing signal. A lot of trees, but drone was high above trees. Lost sight of drone due to trees. Pilot error.

Any ideas for the cause?

There were multiple battery communication errors starting at around 222 seconds:

222.775 : {task_e}INFO:i2c3 core recovery||
222.775 : 13313 [L-BATTERY][ERROR] smbus_read CMD_OP_STATUS error||
222.786 : {task_e}INFO:i2c3 core recovery||
222.786 : 13313 [L-BATTERY][ERROR] smbus_read CMD_CHG_STATUS error||
222.786 : 13313 [L-BATTERY][ERROR] status read err_cnt 2||
223.821 : {task_e}INFO:i2c3 core recovery||
223.821 : 13365 [L-BATTERY][ERROR] CMD_REM_CAP error||
223.827 : {task_e}INFO:cmd 0x7B datalen 2 pec error||
223.827 : 13365 [L-BATTERY][ERROR] CMD_TRUE_FCC error||
223.838 : {task_e}INFO:i2c3 core recovery||
223.838 : 13366 [L-BATTERY][ERROR] CMD_TRUE_RC error||
223.840 : {task_e}INFO:cmd 0x81 datalen 2 pec error||
223.840 : 13366 [L-BATTERY][ERROR] CMD_DODEOC error||
223.852 : {task_e}INFO:i2c3 core recovery||
223.852 : 13367 [L-BATTERY][ERROR] CMD_QSTART error||
223.856 : {task_e}INFO:cmd 0x82 datalen 2 pec error||
223.856 : 13367 [L-BATTERY][ERROR] CMD_QMAX error||
223.866 : {task_e}INFO:i2c3 core recovery||
223.866 : 13367 [L-BATTERY][ERROR] CMD_QMAXDOD0 error||

Followed by repeated app connection issues starting a second or so later:

223.871 : 13368 [L-RC]rc_connect:1=>0
223.871 : 13368 [L-SYS]app lost connection!
223.871 : 13368 [L-GEO]lost app, clear app_pos_info
223.871 : 13368 [L-RC]rc_func_disable @ [269639 ms]
223.871 : 13368 [L-SEND DATA]app connect changed:last(1) != current(0)
224.051 : 13377 [L-RC]rc_connect:0=>1
224.051 : 13377 [L-SYS]app connected!
224.051 : 13377 [L-RC]rc_resume @ [269819 ms]

The actual voltage reporting looks okay:



To me this looks like a faulty battery or improperly installed battery. Can you post the txt log for that flight - it has a few extra relevant data fields.

 

[ballerhe75]

Did you have your drone set to RTH on controller signal loss?
What was your altitude before RTH, especially in relationship to the trees you mention?

Also noticed you took off at 44% battery... not much time.

RTH on lost signal. I think so.

Altitude? 400 + feet.

44% battery. I had 24% with 900+ feet drone home.

 

[Meta4]

RTH on lost signal. I think so.

Almost no-one ever changes the default which is RTH.
Unless you changed it, it will always be RTH.

Phantomhelp doesn't want to open the file you attached.
Try this ...
Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it gives you.

 

[ballerhe75]

Almost no-one ever changes the default which is RTH.
Unless you changed it, it will always be RTH.

Phantomhelp doesn't want to open the file you attached.
Try this ...
Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it gives you.

Flight Record, not Flight Log?

 

[Meta4]

Flight Record, not Flight Log?

It doesn't matter what you call it.
But if you follow the instructions given, we'll get some flight data to look at and maybe make sense of it.

 

[sar104]

RTH on lost signal. I think so.

Altitude? 400 + feet.

44% battery. I had 24% with 900+ feet drone home.

That's AirData's conversion of a DAT file.

TXT log: DJI Flight Log Viewer | Phantom Help

 

[ballerhe75]

Flight Record

 

[sar104]

Flight Record

OK - the battery status went abnormal (unspecified) at 265 seconds, just before failure. It looks like an improperly latched battery - the disconnect registered 0.1 seconds after you went from full climbing throttle to centered, which would have led to rapid vertical deceleration. The previous errors were likely because it wasn't making proper contact.

 

[ballerhe75]

OK - the battery status went abnormal (unspecified) at 265 seconds, just before failure. It looks like an improperly latched battery - the disconnect registered 0.1 seconds after you went from full climbing throttle to centered, which would have led to rapid vertical deceleration. The previous errors were likely because it wasn't making proper contact.

So, at 900+ feet from home the weak signal and loss of connection was due to a loose battery?

 

[sar104]

So, at 900+ feet from home the weak signal and loss of connection was due to a loose battery?

The "weak signal" message is a euphemism for "no signal at all" and is just the app telling you that the RC lost the downlink. The loss of downlink was due to sudden power loss when the battery dislodged.

 

[ballerhe75]

The "weak signal" message is a euphemism for "no signal at all" and is just the app telling you that the RC lost the downlink. The loss of downlink was due to sudden power loss when the battery dislodged.

Thanks for your help. I suspect I did not get the battery “clicked” all the way in.

 

[paulatkin73]

OK - the battery status went abnormal (unspecified) at 265 seconds, just before failure. It looks like an improperly latched battery - the disconnect registered 0.1 seconds after you went from full climbing throttle to centered, which would have led to rapid vertical deceleration. The previous errors were likely because it wasn't making proper contact.

Or, perhaps, not an improperly latched one, but a faulty one that started swelling until it pushed itself out of a latch and then out of a connector.
Who knows...

 

[sar104]

Thanks for your help. I suspect I did not get the battery “clicked” all the way in.

Or, perhaps, not an improperly latched one, but a faulty one that started swelling until it pushed itself out of a latch and then out of a connector.
Who knows...

There have been a few reports of this happening.

Did you recover the aircraft?

 

[Paradigm]

The more I read these stories the more I want to use the velcro straps I bought when I first read about these things happening.

Anyone use straps for every flight?

Anyone get saved by them?

I’m kinda worried about blocking sensors, added weight, drag coefficient increasing(lol yeah I know).

 

[paulatkin73]

i started using velcros, yes. dunno, there is not much statistics yet about those betteries issues, but, in a lot of logs sar104 looked at the failure was preceded by interruption of battery status communication. so, go figure.

 

[ballerhe75]

There were multiple battery communication errors starting at around 222 seconds:

222.775 : {task_e}INFO:i2c3 core recovery||
222.775 : 13313 [L-BATTERY][ERROR] smbus_read CMD_OP_STATUS error||
222.786 : {task_e}INFO:i2c3 core recovery||
222.786 : 13313 [L-BATTERY][ERROR] smbus_read CMD_CHG_STATUS error||
222.786 : 13313 [L-BATTERY][ERROR] status read err_cnt 2||
223.821 : {task_e}INFO:i2c3 core recovery||
223.821 : 13365 [L-BATTERY][ERROR] CMD_REM_CAP error||
223.827 : {task_e}INFO:cmd 0x7B datalen 2 pec error||
223.827 : 13365 [L-BATTERY][ERROR] CMD_TRUE_FCC error||
223.838 : {task_e}INFO:i2c3 core recovery||
223.838 : 13366 [L-BATTERY][ERROR] CMD_TRUE_RC error||
223.840 : {task_e}INFO:cmd 0x81 datalen 2 pec error||
223.840 : 13366 [L-BATTERY][ERROR] CMD_DODEOC error||
223.852 : {task_e}INFO:i2c3 core recovery||
223.852 : 13367 [L-BATTERY][ERROR] CMD_QSTART error||
223.856 : {task_e}INFO:cmd 0x82 datalen 2 pec error||
223.856 : 13367 [L-BATTERY][ERROR] CMD_QMAX error||
223.866 : {task_e}INFO:i2c3 core recovery||
223.866 : 13367 [L-BATTERY][ERROR] CMD_QMAXDOD0 error||

Followed by repeated app connection issues starting a second or so later:

223.871 : 13368 [L-RC]rc_connect:1=>0
223.871 : 13368 [L-SYS]app lost connection!
223.871 : 13368 [L-GEO]lost app, clear app_pos_info
223.871 : 13368 [L-RC]rc_func_disable @ [269639 ms]
223.871 : 13368 [L-SEND DATA]app connect changed:last(1) != current(0)
224.051 : 13377 [L-RC]rc_connect:0=>1
224.051 : 13377 [L-SYS]app connected!
224.051 : 13377 [L-RC]rc_resume @ [269819 ms]

The actual voltage reporting looks okay:

View attachment 77820

To me this looks like a faulty battery or improperly installed battery. Can you post the txt log for that flight - it has a few extra relevant data fields.

Where in the flight logs did you find these specific errors?

 

[ballerhe75]

There have been a few reports of this happening.

Did you recover the aircraft?

The drone was lost. Very thankful for State Farm insurance.

 

[sar104]

Where in the flight logs did you find these specific errors?

Those are in the DAT file event stream.

The drone was lost. Very thankful for State Farm insurance.

You never found it, or it was completely destroyed?