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An Oldie But Goodie Drone Disappearing Act!!

billt1970

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Friends,

First off, thanks to everyone who contributed to my recent thread "Mavic 2 Pro Crash Dive." It should be repaired by next week; meanwhile I'm waiting for word from the insurance company regarding coverage for the loss.

My positive experience (valuable responses) with the above post leads me to go back in time to get some assistance (possibly) in understanding what went wrong with my brand spanking new Mavic 2 Pro back in September 2018. I received the Mavic 2 Pro on August 27th and flew it locally for a few days. The big event for that Labor Day Weekend was the funeral and burial of Senator John McCain at the Naval Academy on Sunday, September 2nd, 2018.

So, I positioned myself in a perfect (so I thought) location across the Severn River from the Naval Academy Cemetery at the "Governor Ritchie Scenic Overlook" that is immediately adjacent to the Maryland World War II Memorial. This location sits a hundred feet or so above the Severn River and offers a spectacular vista of the Naval Academy and Annapolis across the river. The problem was there was no hard schedule for the actual burial of Senator McCain. The Funeral Service at the Naval Academy Chapel was set for 2pm, and that dragged on forever with no signs of ending.

It is noteworthy that the Naval Academy property is a Restricted Flight Area where you are not supposed to fly. I had checked this out carefully, and knew that I SHOULD be able to fly right up to the seawall near the cemetery and shoot from there at 2-300ft up. I used up two of my three batteries guessing wrong about the timing. And so, I waited at the overlook with my third battery reserved for when the funeral party with the casket finally appeared across the river.

While I was waiting, with about a dozen or more other interested folks with their binoculars and cameras, two black-clad and armed DoD police officers appeared asking who was flying the drone? I immediately fessed up; showed them the drone, my FAA Registration Card, and my FAA Remote Pilot Certificate. I mentioned that I was intentionally flying in non-restricted space. They didn't argue that point, but DID make the point that they had been asked by the powers that be to find the drone pilot and ask them to cease and desist flying so close to the cemetery, open air space or not. I didn't argue with them, but did ask if it was acceptable for me to fly the drone from the other side of the river? They agreed that was probably OK so long as I stayed close to the shoreline across the Severn River.

And so, I relocated my launch point down near the river in the parking lot of a popular restaurant, the Severn Inn. When I saw the funeral procession approaching the cemetery across the river I launched the Mavic 2 Pro and sought to find a good place to photograph from afar. It took me a couple of minutes to find the the initial shooting position, but finally did so and started taking photos. Shortly thereafter I re-positioned the drone for a better shooting position. Around 6 minutes into the flight I noticed that I was having problems controlling the aircraft. Based upon the video feed, it was NOT responding to lateral movements that would show up on the iPad screen. Then the video link was lost for some seconds, before being restored, then lost again. The last thing I saw on the iPad was the drone apparently sitting in dense bushes. Unfortunately I was not able to get a screen shot, but I know for a fact that it did NOT land in the water. The flight logs and records end at 7minutes and 14 seconds, with the drone positioned 10 yards or so off shore.

I have no idea if the aircraft landed at 7:14, or if it landed on its own after that. But I do know that I saw the image of it sitting in dense foliage. It definitely did NOT land in the water. With the cooperation of local residents I searched for several days to find the aircraft, to no avail. I even took my Mavic Air there on several occasions to see if I could locate the lost aircraft from the air.

The rest of the story is that I did NOT yet have insurance for my two aircraft, though I DID have DJI Care Refresh for both. BUT, with DJI Care Refresh you must return the aircraft, even in pieces, to get coverage. Lost aircraft equals lost coverage, unless there was some aircraft failure. I wrangled with DJI for a week as to whether something went wrong, but all they could come up with was that, "
The aircraft worked in GPS mode, and responded to the pilot’s control well; At t=07:15, h=69 m, d=507 m, the record ended when the aircraft was hovering." That was an expensive ($874) lesson that I will try not to repeat.

I am attaching the Flight Record for my 3rd and fatal flight that day, plus some screenshots captured from DJI GO4 replaying the flight. I know that the Flight Log was SYNC'D to DJI, but then deleted from the iPad. I'm presently at a loss as to how to recover the Flight Log (.DAT file) from my account at DJI to share with you. Any ideas there? Also, if there is anything else that might be helpful, just let me know. Thanks in advance for any insights you might be able to provide.

Best Regards,

Bill Taylor
301-346-7202
[email protected]
Gambrills, MD
 

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That's certainly unusual. The log just stops with the aircraft hovering. There were a number of short signal drops, and at relatively short range for the M2, with no obvious explanation. In any case, it should have returned under failsafe RTH if the connection were permanently lost. The fact that you later saw live images after it landed is inconclusive, since with the motors off it would not have resumed or created a new txt log. The DAT file(s) would contain the definitive information including, most likely, the coordinates where it landed, but unless you can persuade DJI to send those to you then that's off the table.
 
I have no idea if the aircraft landed at 7:14, or if it landed on its own after that. But I do know that I saw the image of it sitting in dense foliage. It definitely did NOT land in the water. With the cooperation of local residents I searched for several days to find the aircraft, to no avail. I even took my Mavic Air there on several occasions to see if I could locate the lost aircraft from the air.
The flight data doesn't give away any secrets.
It shows you flying to a position 1630 ft south of the home point by 4:59.5 and hovering there 226 feet up.
When the data ends at 7:15.4 the drone was still hovering in place 226 feet up.
There's no wind problem showing in the data.
There was an early warning: warnings:Mobile device CPU fully loaded. Related performance will be affected.
This suggests the tablet was having trouble keeping up with the app data at that point - probably a slow, old tablet?
Whatever happened to the drone, it was after the data stopped.
 
The DAT file(s) would contain the definitive information including, most likely, the coordinates where it landed, but unless you can persuade DJI to send those to you then that's off the table.
Thanks, @sar104. I'll start working on DJI tomorrow to release the .DAT file.

BT
 
The flight data doesn't give away any secrets.
It shows you flying to a position 1630 ft south of the home point by 4:59.5 and hovering there 226 feet up.
When the data ends at 7:15.4 the drone was still hovering in place 226 feet up.
There's no wind problem showing in the data.
There was an early warning: warnings:Mobile device CPU fully loaded. Related performance will be affected.
This suggests the tablet was having trouble keeping up with the app data at that point - probably a slow, old tablet?
Whatever happened to the drone, it was after the data stopped.
Thanks for your thoughts, @Meta4. That's the operative question: "Whatever happened to the drone?" I still go back periodically to look around, but no success to date.

BT
 
Me thinks that perhaps the military had used one of their anti-drone tool/gun to disrupt the signal and make is land.
Interesting that you bring up that possibility, @RayOZ. I'm not a conspiracy type, BUT on that day I did experience some indications of interference with the telemetry and video signals with the aircraft. I had, and have since, flown numerous times from that same vicinity with no problems, but that day there WERE some anomalies. We won't know more, unless I am lucky enough to locate the aircraft 20 months later.

BT
 
I just sent DJI support an email requesting the Flight Log “2018-09-02 15_43_18- 163DF84001L6UH.DAT”. We'll see how they respond.

BT

That's not the correct file - where did you get that file name from? You need the DAT file ending FLY017.DAT
 
Depends on the tool? It could disrupt telemetry and make it think it’s in a NFZ. In that scenario, it would start to land.
And the loss of telemetry?
The anti-drone idea is probably extremely unlikely.
 
And the loss of telemetry?
The anti-drone idea is probably extremely unlikely.

It's not unreasonable to expect some sort of counter terrorism measures at such a funeral service.
There would be many attractive targets (political, dignitaries etc) for such an attack by drone (or other means), as unlikely this may be, and with almost nil previous such events to date.
I could see some secret service types having anti drone tech available on the spot.

I was looking at some of the Droneshield products a while ago.
They have immediate loss of video transmission back to the pilot, and can bring the drone to the ground (other surface) below, or have it return to its starting point to help track a drone pilot.

 
Depends on the tool? It could disrupt telemetry and make it think it’s in a NFZ. In that scenario, it would start to land.
It's not unreasonable to expect some sort of counter terrorism measures at such a funeral service.
There would be many attractive targets (political, dignitaries etc) for such an attack by drone (or other means), as unlikely this may be, and with almost nil previous such events to date.
I could see some secret service types having anti drone tech available on the spot.

I was looking at some of the Droneshield products a while ago.
They have immediate loss of video transmission back to the pilot, and can bring the drone to the ground (other surface) below, or have it return to its starting point to help track a drone pilot.


There are a few comms disruption technologies deployed in the US, but not widely at all, and not at this kind of event. And none of those disrupt GNSS, which is what would be required to prevent RTH.
 
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There are a few comms disruption technologies deployed in the US, but not widely at all, and not at this kind of event. And none of those disrupt GNSS, which is what would be required to prevent RTH.

Such a major event ?
Surely there'd be a massive amount of covert surveillance ?

From the link above . . .

GNSS Disruption: Optional GNSS disruption capability (GPS, GLONASS)
 
Such a major event ?
Surely there'd be a massive amount of covert surveillance ?

From the link above . . .

GNSS Disruption: Optional GNSS disruption capability (GPS, GLONASS)

Technically feasible, but completely illegal to use, even for LE.
 
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What struck me as they might have some anti drone tech around was this . . .

two black-clad and armed DoD police officers appeared asking who was flying the drone?

They pinpointed the area the OP was located pretty well, enough to ask the question so he (and others nearby) could hear.
Appears to be about 500m away form the opposite shore.
Must have been DJI Aeroscope to do this ?

If other organisation agents were on site (and you can bet there would be) then it's entirely feasible they could have Droneshield type 'gadgets' to play with.
The Dept of Defence Police may not have communicated their investigation of the OP (pilot) situation to other operatives either.

Be an interesting DAT if the OP can get it from DJI, and if it reveals anything more.
 
Even if they disrupt the comms it is still going to execute failsafe RTH.
Do we know this? Sure under normal operating circumstances we do. But DJI sell drone-monitoring systems to various agencies, who knows whether some sort of backdoor is included in the package when it's sold to particular security services. Or governments have the resources to sniff occusync and do something malicious in the interests of security. Wifi would be even easier. Who knows how these drones behave if they receive two identically authenticated signals, one commanding the drone to do one thing, another telling it to do another.

Ok, I'm clearly I'm no sort of expert :) And I have zero idea what happened in this case, but I wouldn't rule out some sort of "official" interference.
 
Do we know this? Sure under normal operating circumstances we do. But DJI sell drone-monitoring systems to various agencies, who knows whether some sort of backdoor is included in the package when it's sold to particular security services. Or governments have the resources to sniff occusync and do something malicious in the interests of security. Wifi would be even easier. Who knows how these drones behave if they receive two identically authenticated signals, one commanding the drone to do one thing, another telling it to do another.

Ok, I'm clearly I'm no sort of expert :) And I have zero idea what happened in this case, but I wouldn't rule out some sort of "official" interference.

I think we can conclude that because Aeroscope is unable to control DJI aircraft - only detect them, while jamming just overwhelms the comms link signal, and doesn't provide any control.
 
I think we can conclude that because Aeroscope is unable to control DJI aircraft - only detect them, while jamming just overwhelms the comms link signal, and doesn't provide any control.
Presuming there isn’t some unknown, unannounced, non-commercial tech provided to DoD or USSS by NSA or the like?
 
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