How to stop a "run away" when Mavic Pro is in your hand?

[BudWalker]

.......

Using BudWalker's posts, I have found some data on the FC which are close to the 23 June 2021 date the fly away happened. I have supplied a compressed .dat file and provided a DropBox link. I have no idea what is in those files.....they are about the right date but have 6 flight segments. I only did one flight segment but with all my panic moves to shut down the rotors, I could have inadvertently created extra virtual flight segments. I am hoping they shed some light on what happened.

The FLYXXX.DAT files contained in DJI_ASSISTANT_EXPORT_FILE_2021-06-27_22-13-47.DAT
all occurred yesterday, 6/27/2021.

Can you, instead, select all the flights shown in DJI Assistant 2 and create another DJI_ASSISTANT_EXPORT_FILE_XXXXXX.DAT?

 

[tjcooper]

BudWalker,
I can make the new .DAT that contains about 10-12 flights in the list. But all the OTHER flights are for many weeks earlier than the 23 June 2021 incident. So I assumed they could not be for the flight that had the problem. Will do tonight. At Hospital now. No bandwidth.

Oh, I did get two "USB port x" listings when I connected the FC to my PC. Problem was that if I clicked on either one, the PC said that I needed to insert "media" into the device. SO I am thinking it knows they are there on the FC but does not know how to read their file structure.

 

[BudWalker]

BudWalker,
I can make the new .DAT that contains about 10-12 flights in the list. But all the OTHER flights are for many weeks earlier than the 23 June 2021 incident. So I assumed they could not be for the flight that had the problem. Will do tonight. At Hospital now. No bandwidth.

Oh, I did get two "USB port x" listings when I connected the FC to my PC. Problem was that if I clicked on either one, the PC said that I needed to insert "media" into the device. SO I am thinking it knows they are there on the FC but does not know how to read their file structure.

Yes, please create the .DAT containing all of the flights.

 

[tjcooper]

Meta4,
I think I may have found something that explains why I cannot see the "data set" you requested in post #28 that you wanted. I have nothing in my NDL software that looks anything like your display in post #28. What I do have is a "Library" entry that shows a picture of all flights I have taken over some period of time. I just ran the original "Go Fly 4" app on my cell phone. It still takes me into the NDL app. When I connect with the FC and RC unit, I can see the library of previous flights (just a single picture) and they start in 2014 and end in 2020. So the Go Fly 4 app is not finding any new flight records.

So I am thinking that I don't have your flight log that you showed in post #28. Can you tell me all the exact steps you use to get into that display? I saw in the flight instructions on the NDL app that the system will cache to the directory on the cell phone of "...DJI/DJI.pilot.pad". So I am guessing that is why I see my flight records when I do and they are not where you would normally see your flight records.

Regardless, a search of both visible, deleted, or hidden .txt and/or .dat files does not show any record within a day or so of the critical event of 23 June 2021.

I will us DJI Assistant and make another collection of all flights on my FC to send to BudWalker. I hope that that "full collection" will have some flight record of the critical event. Thanks for being patient.
Ted Cooper

 

[Meta4]

So I am thinking that I don't have your flight log that you showed in post #28. Can you tell me all the exact steps you use to get into that display?

I don't know what NLD does to your app or how NLD is used.
When you fly, do you use the DJI app or an NLD app?
That the flight record you posted for a previous flight is in there suggests that there should be records for any flights that were done with whatever app you used to make that flight.
And you would expect them to all be in the same directory.

Here's how you access the flight listing in DJI Go4.
The red arrows show where to click.

 

[dirkclod]

@tjcooper please post what has been asked of you.
There is no need of over 60 post in this. If you cant
i see no need of this going further. Just be awhare
this is not going to continue If you don’t.

 

[danny_2020]

I have 300 hours of flying on Mavic Pro units. Today I was at an outdoor party and wanted to take video of the picnic group. Took off from an empty table. Unit could only get to ALTIMODE because was having trouble getting enough satellites. That was OK because I only planned to fly in a 30 foot circle at 8 feet altitude and only take video. Went through the process of taking video for about 7 minutes. Everything under normal control. Started to land on an empty table. Without warning the AC went left and came down to 4 feet and flew into a friend sitting at the table. AC bounced off his back side and I was able to grab unit after it hit the table and popped up.

Having grabbed it from above, I was able to keep control and force the unit onto the table top. It was running at almost full power and trying to climb. I held it down and used the other hand to push the throttle to zero.....nothing changed. I hit the "power button" and held it until controller said "SHUTTING DOWN".......again......nothing changed. I repowered on the controller and tried to initialize it. AC still flying very had in my hand.

I then reached around on AC and double hit the battery power button to go to power off status.......nothing changed. After a minute or two of holding the AC on the table top I was able to position my right hand to go under the AC and grab the battery lock down buttons. I squeezed then and then used the other hand to lift the battery up. Finally the AC powered off. It is the worst fly away condition I have ever seen. Has anyone else ever had this happen? Any causes found?
I will try to dump the flight logs tonight and see if I have anything on the AC or in the controlller. What is the best way to get a dump?
Ted Cooper

I have had this problem before, but the only thing different was that my drone didn't collide with anyone... I don't know why it did this. When this happened to me, I knew that flipping it over would shut it down, so I did that, but oddly enough, it didn't shut down... I had to do something similar to what you did and take the battery out or something...

 

[SpitFire]

Glad that nobody was hurt. I would be interested in you posting your flight log. So, we can confirm what actually happened, why the MP acted the way it did. On the recreational UAS safety test, (Trust). Remember, the person flying the drone is ultimately responsible for all the aspects for the flight, including where it flies, how high it flies, and that all rules and regulations are followed. Checking your self, that its your responsibility to ensure that you are mentally and physically fit to fly. Another section of the safety test,
deals with Automated features, like the follow me. The drone can hit obstacles or people that are near you. After completing this knowledge test, each person has to have it with them if asked by the authorities.
Personally, I think it's great, each pilot will be held accountable for how they fly the Bird.

 

[tjcooper]

BudWalk,
here is the Dropbox link to the full set of flight plans for my Mavic Pro. Thirteen in all. Also here is the full list of flight plans. Maybe this afternoon I will do a "captured flight" (put the drone on a nylon card so it cannot fly away if something goes wrong. I will go up to 8 feet and fly in gentle circles then land. I want to see where my NLD program puts the new files both on my cell phone and on FC. That should answer a lot of questions.

link:

Dropbox

www.dropbox.com

 

[tjcooper]

dirkclod,​

I agree that 60+ posts are excessive, but given that we have someone chime in that they had the same thing happen and the turning FC upside down DID NOT STOP the rotors, this potentially points to a real problem. I hope he has the FC logs to relay what happened.

I have not been able to post the files that Meta4 wants BECAUSE THEY DO NOT EXIST on my cell phone in the locations posted by Meta4. But I do have .txt files in alternate directories that I believe the NLD app uses to list flight parameters. But I don't have any .txt files for the flight of 23 June 2021. And even the flight log for 29 July does not show any data for the "fly away" even that BudWalker thought might be there.

So please let BudWalker examine the FC flight logs to see if they cover the "fly away" event. If it turns out to be pilot error, then shame on me. If it turns out to be a real problem, then shame on anyone who stops the investigation. My honest intuition is that we don't have a flight log for that flight. The act of pulling out the battery during "live flight" may compromise the OS to not finish closing out the files on both the cell phone and the FC.

Meta4,
Great pictures. I assume that I do not use the "enter device" menu but rather in the GO FLY 4 app just find out where the "me" icon is located and go to that spot? I have never seen that 2nd display you showed on your system, but I have never looked for it either. I normally fly with DJI googles on and the display is rather limited in that device. Only when I troubleshoot compass problems, etc. do I look in the other menus.

 

[BudWalker]

BudWalk,
here is the Dropbox link to the full set of flight plans for my Mavic Pro. Thirteen in all. Also here is the full list of flight plans. Maybe this afternoon I will do a "captured flight" (put the drone on a nylon card so it cannot fly away if something goes wrong. I will go up to 8 feet and fly in gentle circles then land. I want to see where my NLD program puts the new files both on my cell phone and on FC. That should answer a lot of questions.

link:

Dropbox

www.dropbox.com

None of the .DATs contained in DJI_ASSISTANT_EXPORT_FILE_2021-06-29_13-10-54.DAT
come from the incident you described. In fact, most of the contained .DATs were created recently when you were attempting to retrieve that elusive .DAT.

I gotta ask. You sound like a guy who might have more than one MP - I did for a while. If so, is it possible you were using a different MP?

 

[Meta4]

I normally fly with DJI googles on and the display is rather limited in that device.

That little piece of information is highly relevant.
It's unfortunate it wasn't revealed earlier.
If you used the goggles rather than the phone, there won't be any flight data recorded on the phone.

 

[tjcooper]

BudWalker,
I have only one MP. I did the "captured flight" today with drone tethered to cord and flies no higher than 4-5 feet in small circle. I find no .txt or .dat on the cell phone for this flight (shouldn't it be there?). But on MC I have 2 sets of flights: one for 27 JUN and another for today 29 JUN. I have used DJI Assistant and made the compressed files. Do you know why 2 different dates would be created? Does the 10 minute flight look normal to you? Is there a place somewhere to learn how to get the basic commands and flight path out of .dat file? Thanks.
link:

Dropbox

www.dropbox.com

QUESTION: how do you think the the .dat files I sent last time were not real flights but came into being because I was using the DJI Assistant to export the data from the FC? Very confused about this.

Meta4,
I did NOT use goggles during the fly away event. I would have mentioned that immediately if I had. Flying with googles on around people is crazy if you don't have a spotter standing beside you.

I was able to find on both Go FLY 4 and the NLD app flight data downloaded from the Web. The Go FLY 4 app has no flights listed for me since my MP purchase. Totally EMPTY The NLD app has the exact same display but the data structure shows flights up to the last ones in 2020. Nothing for 2021 which the FC has in its database. So I am guessing that you have to return home from flying and allow the cell phone using the app to manually upload your flight data? I don't do anything with the cell phone when I finish flying (it has no SIM in it).

See the notes to BudWalker above. My "captured flight" has nothing on the cell phone but does have some dat for two sets of dates. Hope they are normal. I did fully setup to GPS for captured flight.
Later this week I hope to re-create the fly away event. I will take off from the ATTimode and fly for a few minutes. I will then grab the drone out of the air, hold it in my hand, then putt the battery out while rotors still turning. I want to see if any data gets written to cell phone (highly unlikely) or to the FC (not clear what I will find).

 

[Meta4]

So I am guessing that you have to return home from flying and allow the cell phone using the app to manually upload your flight data? I don't do anything with the cell phone when I finish flying (it has no SIM in it).

DJI flight records do not require you return home.
Even for partial flights, it records the flight up to the point signal is lost.
You posted data from a previous flight that is completely normal.
If NLD was used for that flight, that indicates that the flight data is just the same.

Later this week I hope to re-create the fly away event.

Even without seeing your flight data (and I've given up hope of ever seeing it), your drone did not fly away.
And recreating the circumstances that caused the incident won't be possible when you have no way to find what those conditions were.

The incident you described was typical of what happens when you try to restain a drone that thinks it should be somewhere else.
That could have been because RTH was initiated or maybe it just wanted to move a couple of feet due to slightly dodgy GPS reception.

Your drone will be fine and there's no need to worry about it flying away in future.
DJI drones just don't do that.
Just wait for GPS and fly in an area where GPS reception isn't blocked by buildings, tree cover etc, and you won;'t have any problems with it.

 

[BossBob]

dirkclod,​

I agree that 60+ posts are excessive, but given that we have someone chime in that they had the same thing happen and the turning FC upside down DID NOT STOP the rotors, this potentially points to a real problem. I hope he has the FC logs to relay what happened.

I’ve no idea if NLD has this option but it is possible to turn off the “shut down motors on excessive tilt”. I don’t remember if it was in Superpatcher or in the original editable functions of DJI assistant. It could be that this is buried in the NLD options and has been selected. It might even be a default given that NLD enables more radical angles of tilt.

 

[BudWalker]

BudWalker,
I have only one MP. I did the "captured flight" today with drone tethered to cord and flies no higher than 4-5 feet in small circle. I find no .txt or .dat on the cell phone for this flight (shouldn't it be there?). But on MC I have 2 sets of flights: one for 27 JUN and another for today 29 JUN. I have used DJI Assistant and made the compressed files. Do you know why 2 different dates would be created? Does the 10 minute flight look normal to you? Is there a place somewhere to learn how to get the basic commands and flight path out of .dat file? Thanks.
link:

Dropbox

www.dropbox.com

QUESTION: how do you think the the .dat files I sent last time were not real flights but came into being because I was using the DJI Assistant to export the data from the FC? Very confused about this.

Meta4,
I did NOT use goggles during the fly away event. I would have mentioned that immediately if I had. Flying with googles on around people is crazy if you don't have a spotter standing beside you.

I was able to find on both Go FLY 4 and the NLD app flight data downloaded from the Web. The Go FLY 4 app has no flights listed for me since my MP purchase. Totally EMPTY The NLD app has the exact same display but the data structure shows flights up to the last ones in 2020. Nothing for 2021 which the FC has in its database. So I am guessing that you have to return home from flying and allow the cell phone using the app to manually upload your flight data? I don't do anything with the cell phone when I finish flying (it has no SIM in it).

See the notes to BudWalker above. My "captured flight" has nothing on the cell phone but does have some dat for two sets of dates. Hope they are normal. I did fully setup to GPS for captured flight.
Later this week I hope to re-create the fly away event. I will take off from the ATTimode and fly for a few minutes. I will then grab the drone out of the air, hold it in my hand, then putt the battery out while rotors still turning. I want to see if any data gets written to cell phone (highly unlikely) or to the FC (not clear what I will find).

A .DAT is created every time the battery is turned on. That includes those non-flights where the battery was turned on to use the DJI Assistant 2.

The most recent compressed .DAT that you submitted (DJI_ASSISTANT_EXPORT_FILE_2021-06-29_18-14-43.DAT) does not contain a .DAT where the motors were started. It does, however, contain a non-flight.

At this point I suspect that the NLD software prevents a .DAT from being recorded if there is an actual flight.

If you're interested in using either DatCon or Csv View check out the user manuals that are available via the Help button on both DatCon and CsvView. You should also check this excellent article
Mavic Flight Log Retrieval and Analysis Guide

 

[WildDoktor]

I will then grab the drone out of the air, hold it in my hand, then putt the battery out while rotors still turning.

Dude...please please do NOT do this again. That is just a bad, bad idea. It's unbelievable that you did this once without going to the hospital for stitches...or worse.

 

[tjcooper]

BudWalker,
Much thanks for your contributions to looking at the .dat files. I have done a lot of this for Mission Planner and QuanumNova machines, but never for DJI machines. Just to be sure, every time I hit the battery power button to the ON state, I will get a new .dat file in FC? So that would explain why I had two different dates in .DAT set I sent to you. But I am blown away but you not having my 10 minutes "real flight". Meta4 says that the .txt file I previously uploaded (definitely run by NLD app) shows a normal flight. So I have no idea why the "captured flight" was not shown on FC.

Is there a way to erase all previous .dat files on FC so I can start testing with a "clean slate"? Will run several full flights this weekend and see what appears on cell phone and on FC. Thanks for references on how to use CsvView programs. You are a really great person.

WildDoctor,
I completely agree with you. Grabbing a running drone out of the air is REALLY DANGEROUS. But there is no other way I can think of to find out if .dat files are truly written to FC (and also to cell phone) if the battery is removed. On the safe side, I will grab drone from underneath where there is no blade exposure. I will use Kevlar gloves and a full face mask when I do this. On the plus side, 30 years of black belt Shotokan experience makes my hands very fast. Regardless of these comments, no one should grab a moving drone. When the "fly away" event happened, the MP had already hit someone in the back and was making its way across the table to potentially strike other people in the face. My choice was either to "wait and see what happens" or to put my hand into its path and take it down. Luckily my quick hands got it and my grab on top kept my fingers out of harm's way. The "free clearance" on the top of the drone only offers about 1 inch of clearance around the grab position of the hand.

 

[slup]

...Just to be sure, every time I hit the battery power button to the ON state, I will get a new .dat file in FC?...

Yes ... the DAT log (on the AC itself & on to a connected mobile device) runs from power on to power off. The mobile device TXT log runs from motors on to motors off.

Is there a way to erase all previous .dat files on FC...

No ... you can only delete the DAT's on the mobile device.

...Grabbing a running drone out of the air is REALLY DANGEROUS. But there is no other way I can think of to find out if .dat files are truly written to FC (and also to cell phone) if the battery is removed...

Have seen numerous of DAT logs from cases where the AC have lost power ... so they are properly written even though you pull the battery, no need to perform that dangerous stunt with pulling the battery from a AC with running motors to determine that. If you persist ... you could instead power on your AC (which starts the DAT log writing), & then without starting the motors (no TXT log will be created) just pull out the battery.

 

[tjcooper]

SUMMARY of what has been learned in this 80 post thread on the "fly away" of 23 June 2021. I am giving the primary items and will edit later to fill in details in next few days.

1) on BOTH the FC and the MOBILE, there are no files that record .txt or .dat or .log for the "fly away" scenario. The 30+ people at the picnic can testify that I took off, flew circles around each table trying to capture video, and the "run away" as I tried to land that went into one person's back. There are no records of the stills or video. No clue why
2) the NLD app that allows me to fly without NFZ limitations does NOT write its FlightData into the same directory structure that GO fly 4 uses. It does write the .txt and .dat into a similar directory structure under the .../DJI/dji_pilot_pad/FlightRecord space.
3) In the motorspeed space of FC for .dat the motor speeds are always zero even though a good flight took place. The left forward current does show the changing motor speed.
4) my 29 June 2021 "captured flight" with a cord on the MP did not leave any .dat or .txt files for either FC or the Mobile. Flight started with GPS but no precision takeoff. There are .log files present in MOBILE for the 29 June 2021 flight. The log files all show "no error" entries.
5) my four flights on 3 July all recorded the normal data of .txt and .dat on both FC and MOBILE. Same comments about no motor speeds shown on FC are present for each flight. The last fight of "grabbing the MP out of the air" did record both video and all .dat and .txt files. One of the 3 July flights was purposely started with no GPS lockdown as I lifted off. Within 15 seconds of flight, the RC said I was now in GPS mode. It is not clear what homepoint was chosen but the RC said I had a homepoint. So it appears that taking off in ATTimode would have made not change in the 23 June fly away event. The system would automatically go into GPS mode as soon as enough satellites were found in the 7-8 minute flight.

I have run PhoneRescue many times on the MOBILE looking for any .dat or .txt files for the 23 June and 29 June flights. Only some "log" files found for 29 June.

So my end conclusion is that I will never know what happened on 23 June "fly away". That the FC has no record of any flight information that day says that some very strange "anomaly" occurred during that 7-8 minute flight.