Matrice 30T Flight with a Lost Link

[jaja6009]

Hello,

I am wondering if the team here can give insight into this flight.
It was a Matrice 30T that had a Lost Link.
I was not the pilot, but am trying to figure out what happened.

The drone did Return to Home and did land safely.

DJI Flight Log Viewer - PhantomHelp.com

 

[msinger]

It was a Matrice 30T that had a Lost Link

What is a lost link?

One possibility is that the remote controller powered off mid-flight.

 

[jaja6009]

Lost link: "A UAS lost link is the interruption of the command and control (C2) signal between a drone and its ground station, which can be due to a lost uplink (commands from ground to drone) or downlink (data/video from drone to ground). When this happens, the drone automatically executes pre-programmed "lost link" procedures, such as returning to a home point, to recover safely. "

I thought the same, but the RPIC stated the controller was on the whole time. I also thought that maybe the app, DJI Pilot 2 froze, but that does not seem to be the case.

The drone was not far from the pilot at all and there is nothing in the area where the lost link happened that produces interference.

I'm hoping the pros can see something I don't.

 

[msinger]

Lost link: "A UAS lost link is the interruption of the command and control (C2) signal between a drone and its ground station, which can be due to a lost uplink (commands from ground to drone) or downlink (data/video from drone to ground). When this happens, the drone automatically executes pre-programmed "lost link" procedures, such as returning to a home point, to recover safely. "

Sorry for the confusion. I just wanted to understand what you meant by "Lost Link". Maybe the RPIC used that term.

It's also not clear whether you're describing something you saw elsewhere or if you were speaking directly with the RPIC about the incident.

the RPIC stated the controller was on the whole time

And the RPIC could see the live camera feed the entire time?

I'm hoping the pros can see something I don't.

Unfortunately, there's nothing to see.

When the flight log ends, everything looks normal, and both the uplink and downlink signals were at full strength. If the RPIC didn't manually initiate RTH, it likely means the uplink suddenly disconnected.

 

[jaja6009]

Sorry for the confusion. I just wanted to understand what you meant by "Lost Link". Maybe the RPIC used that term.

It's also not clear whether you're describing something you saw elsewhere or if you were speaking directly with the RPIC about the incident.



And the RPIC could see the live camera feed the entire time?



Unfortunately, there's nothing to see.

When the flight log ends, everything looks normal, and both the uplink and downlink signals were at full strength. If the RPIC didn't manually initiate RTH, it likely means the uplink suddenly disconnected.

Thank you.


A quick summary:

I was told the drone without warning went into Return to Home.
They could see the video feed, they could not control the drone with stick inputs.
The drone landed at the home point.

I am at a loss. The flight log reminds me of one from an Anafi that lost all power and fell to its death since it just cuts out.

It supposedly has the newest firmware. I still have to go and check the drone myself and will ask some more questions.

 

[samysys]

It seems that the RPIC was using the DJI RC Plus which has 4 antenna. with this distance, antenna (all) failure seems unlikely.

Flight data looks normal so it can be first assumed that the drone was working fine.

If it is not mechanical error, then it is human error.

If the RPIC did not switch off the remote controller, the next most likely reason is lost link due to physical blockage.

The blockage should happened fast: last record indicate still 100% linkage between RC and drone.

Possible situation: operating the drone indoor and some dumb-*** just shout the metallic door, or similarly operate the drone in armor car or car with full metallic exterior and metallic window grille, or a combination of the above.

Other less likely situation: RPIC put the remote in a metal box/ fully cover it with RFID proof clothing.

Check if there are other logs from the same night, esp after this flight. Normally, if such things happened and the RP was not sure about the cause, they don't fly. If there are other normal flight log, that is a strong hints that they knew what happened.

Purely speculation.

 

[msinger]

The blockage should happened fast: last record indicate still 100% linkage between RC and drone.

Yes, the signal loss happened instantly according to the available flight log data. If the remote controller had been covered or blocked, I'd expect to see at least one frame showing the signal starting to drop.

 

[jaja6009]

I asked questions today and pretty much got the same answers.

The RPIC did not enter a vehicle or walk behind something.
There were no radios nearby or other potential sources of interference.

I'm at a loss. Hopefully it was a one off type incident.

Thanks for everyone's input.