Mavic down

[Ronsta@Mav]

Hi first time user long time reader, I'm hoping someone here can help me out. This is how the flight went I unpacked the drone from the carry bag, unfolded the arms, checked the propellers, checked the battery was in firmly, did all pre flight checks, it was later in the afternoon and the wind was minimal, proceeded to takeoff. I did about 15 minutes of flying up and down the creek getting different shots of the creek, I decided to do a point of interest shot. So I climbed up a little and activated the control for (POI). It was going along fine and then I got the message to say the cache was full so I decided to land the drone and attend to this . So I hit the (RTH) on my device all seemed fine the drone did it usual functions came over head and began to descend. As you will see on the flight record it only came down a few meters and then it just fell without warning (it was like it landed at 47.3 mtrs above the ground).
The DJI go app stopped recording at this time as well witch is strange, the Dat files from the flight keep recording all the way to the ground showing a rapid decent in the last 4secs of the flight and seems to have voltage to the motors all the way down as well.
I'm not an expert on this so I could be reading the data incorrectly. any help would be greatly appreciated.

Ill place the dropbox link below.
The files in question are dated 11/03/2018 at 16:34 for the txt file
and the Dat file is 11/03/2018 FLY056 16:33.27

drone data

Thanks

 

[Lake_Flyer]

Sorry for your first crash experience.
Luckily there are a few heros here that can help you determining what caused your RTH crash.

I have said it many times and I keep repeating (only as a friendly advise from a pilot who started flying manual drones well before any autonomy was available);

RTH is a fail safe that hopefully will work when it's absolutely needed, not to be used as a normal flight mode, although most people seem to think it is and claim that it is absolutely fool proof because they never had a problem with it. But by far most problems occur during RTH. Wether by wrong settings by the pilot, a GPS or compass interference, obstacles, a low Sun, and maybe even because of a barometer issue while landing.

It is always better and safer to control the drone yourself, after you learned to master it. Manual take off and landing is safer than any algorithm written by a programmer somewhere in China. The amount of variables in a real life environment are countless and no algorithm in a consumer electronics world is capable of dealing with all of them. 99% RTH works ok but you never know when that 1% is up. Same for auto take off and landing.

 

[Ronsta@Mav]

Sorry for your first crash experience.
Luckily there are a few heros here that can help you determining what caused your RTH crash.

I have said it many times and I keep repeating (only as a friendly advise from a pilot who started flying manual drones well before any autonomy was available);

RTH is a fail safe that hopefully will work when it's absolutely needed, not to be used as a normal flight mode, although most people seem to think it is and claim that it is absolutely fool proof because they never had a problem with it. But by far most problems occur during RTH. Wether by wrong settings by the pilot, a GPS or compass interference, obstacles, a low Sun, and maybe even because of a barometer issue while landing.

It is always better and safer to control the drone yourself, after you learned to master it. Manual take off and landing is safer than any algorithm written by a programmer somewhere in China. The amount of variables in a real life environment are countless and no algorithm in a consumer electronics world is capable of dealing with all of them. 99% RTH works ok but you never know when that 1% is up. Same for auto take off and landing.

Thanks for your reply, now you point that out it does make sense, probably beginner error. Only had the drone for 6 days too witch sucks. Yeah hopefully someone can help me out because I'm not having much luck with DJI at the moment.

 

[Ronsta@Mav]

I've uploaded the flight log here as well for anyone to have a look at.

DJI Flight Log Viewer - PhantomHelp.com

 

[Lake_Flyer]

Thanks for your reply, now you point that out it does make sense, probably beginner error. Only had the drone for 6 days too witch sucks. Yeah hopefully someone can help me out because I'm not having much luck with DJI at the moment.

This is very understandable! Not only beginners push the RTH button in blind faith. DJI makes it all sound very simple and safe. It might however have been something that has little to do with RTH. But while it happened you weren't in direct control. DJI will probably claim a pilot error.

I can't read those logs from here right now unfortunately.

 

[QLDMAVIC]

This is very understandable! Not only beginners push the RTH button in blind faith. DJI makes it all sound very simple and safe. It might however have been something that has little to do with RTH. But while it happened you weren't in direct control. DJI will probably claim a pilot error.

I can't read those logs from here right now unfortunately.

They say that the dat files don’t show altitude all the way to the ground, but I’m sure it does. Anyway hopefully someone can shead some light on it.

 

[Lake_Flyer]

ask sar104

 

[Robert Mitchell]

Following.

 

[BudWalker]

Hi first time user long time reader, I'm hoping someone here can help me out. This is how the flight went I unpacked the drone from the carry bag, unfolded the arms, checked the propellers, checked the battery was in firmly, did all pre flight checks, it was later in the afternoon and the wind was minimal, proceeded to takeoff. I did about 15 minutes of flying up and down the creek getting different shots of the creek, I decided to do a point of interest shot. So I climbed up a little and activated the control for (POI). It was going along fine and then I got the message to say the cache was full so I decided to land the drone and attend to this . So I hit the (RTH) on my device all seemed fine the drone did it usual functions came over head and began to descend. As you will see on the flight record it only came down a few meters and then it just fell without warning (it was like it landed at 47.3 mtrs above the ground).
The DJI go app stopped recording at this time as well witch is strange, the Dat files from the flight keep recording all the way to the ground showing a rapid decent in the last 4secs of the flight and seems to have voltage to the motors all the way down as well.
I'm not an expert on this so I could be reading the data incorrectly. any help would be greatly appreciated.

Ill place the dropbox link below.
The files in question are dated 11/03/2018 at 16:34 for the txt file
and the Dat file is 11/03/2018 FLY056 16:33.27

drone data

Thanks

I was looking at this over on DJI forums where you posted the data. This is probably an incident caused by a battery failure or a battery disconnect. We could be more certain if the .DAT on the Mavic itself exists. That .DAT has higher frequency data and it's possible to see the voltage dropping at the very end. There can be other indications as well. Look here for info on retrieving that .DAT on the Mavic if it exists.

 

[Simmo]

VPS started reading whan the barometer? showed the alititude way higher. I think this analysis is above my pay grade... @sar104 @msinger

 

[sar104]

I was looking at this over on DJI forums where you posted the data. This is probably an incident caused by a battery failure or a battery disconnect. We could be more certain if the .DAT on the Mavic itself exists. That .DAT has higher frequency data and it's possible to see the voltage dropping at the very end. There can be other indications as well. Look here for info on retrieving that .DAT on the Mavic if it exists.

There are a couple of aircraft DAT files in the Dropbox location linked above, but I think they must be the encrypted kind that DatCon can't read - it just hangs on "pre-analyzing".

 

[BudWalker]

There are a couple of aircraft DAT files in the Dropbox location linked above, but I think they must be the encrypted kind that DatCon can't read - it just hangs on "pre-analyzing".

Didn't see those. Maybe they weren't there when I looked earlier on DJI forum. Anyway.. My copy of DatCon 3.4.0 doesn't hang so we need to look into why your copy does hang on PreAnalyze. The contained .DAT is FLY061.DAT which isn't an actual flight, probably just a power up for 176 secs. The incident flight was FLY056.

AFAIK, the Mavic Air is the only platform creating .DATs that are encrypted and DatCon can't read. So far, that is.

 

[Tinmania]

RTH is a fail safe that hopefully will work when it's absolutely needed, not to be used as a normal flight mode, although most people seem to think it is and claim that it is absolutely fool proof because they never had a problem with it. But by far most problems occur during RTH. Wether by wrong settings by the pilot, a GPS or compass interference, obstacles, a low Sun, and maybe even because of a barometer issue while landing.

It is always better and safer to control the drone yourself, after you learned to master it. Manual take off and landing is safer than any algorithm written by a programmer somewhere in China. The amount of variables in a real life environment are countless and no algorithm in a consumer electronics world is capable of dealing with all of them. 99% RTH works ok but you never know when that 1% is up. Same for auto take off and landing.

No offense to you, personally, but I get a kick out of the "control the drone yourself" crowd when they are not really in control at all. I'd like to see them control a quad if all they had were four sliders that controlled each motor's speed individually.

Even a simple landing of a Mavic by pulling down the left stick is only telling the FC that you want to descend. The FC does the actual work, including deciding that it is close enough to the ground to auto-land (as it announces, "Landing").

To me it is silly to not trust a computer to fly, when it is flying it anyway. How many people use Litchi, AutoPilot, et al? Lots. And they are usually not beginners. Yet those apps are often used for preplanned missions where, yep, the FC is doing the "flying."

Sure, if you don't understand RTH or configure it correctly it can lead to a surprise. But that surprise can come at any moment anyway on a disconnect. Why not fully trust it, and test it, so that there is no surprise? You don't wait for a fire to find out fire drills would have helped.



Mike

 

[sar104]

Didn't see those. Maybe they weren't there when I looked earlier on DJI forum. Anyway.. My copy of DatCon 3.4.0 doesn't hang so we need to look into why your copy does hang on PreAnalyze. The contained .DAT is FLY061.DAT which isn't an actual flight, probably just a power up for 176 secs. The incident flight was FLY056.

AFAIK, the Mavic Air is the only platform creating .DATs that are encrypted and DatCon can't read. So far, that is.

It doesn't hang on 061 - I see the same 176 s power up, but 060 extracted from the other assistant file causes it to hang.

 

[BudWalker]

It doesn't hang on 061 - I see the same 176 s power up, but 060 extracted from the other assistant file causes it to hang.

I assume that you used ExtractDJI to extract FLY060.DAT from DJI_ASSISTANT_EXPORT_FILE_2018-03-12_08-23-21.DAT. When I do this the FLY060.DAT doesn't cause DatCon to hang in PreAnalyze. Are you up to date on ExtractDJI? Should be version 1.2.0. Maybe it's time for you to Dropbox your FLY060.DAT so I can take a look..

 

[sar104]

I assume that you used ExtractDJI to extract FLY060.DAT from DJI_ASSISTANT_EXPORT_FILE_2018-03-12_08-23-21.DAT. When I do this the FLY060.DAT doesn't cause DatCon to hang in PreAnalyze. Are you up to date on ExtractDJI? Should be version 1.2.0. Maybe it's time for you to Dropbox your FLY060.DAT so I can take a look..

Extracted with 1.2.0 and attempted to open with 3.4.0. I'll send you a link.

 

[Huge Bama Fan]

This has my attention

 

[Ronsta@Mav]

I was looking at this over on DJI forums where you posted the data. This is probably an incident caused by a battery failure or a battery disconnect. We could be more certain if the .DAT on the Mavic itself exists. That .DAT has higher frequency data and it's possible to see the voltage dropping at the very end. There can be other indications as well. Look here for info on retrieving that .DAT on the Mavic if it exists.

Thanks for your reply I thought I did extract the data from the drone before it left but maybe I did it incorrectly.

 

[Ronsta@Mav]

Hi I cut the excel file I've been looking at and you can see the takeoff GPS height is 681 and at the last entry is 682 yet the relative height is still at 47.8. The motors say that they have power as well. This is what I have been going off as I said I'm not an expert so if I'm reading it wrong please let me know. As for the drone its with DJ now so I don't think I can have another go at the data from that. Those two extracted files were the ones I thought came from the drone.

Dropbox - Cut 2018-03-11_16-33-27_FLY056.csv

 

[black_magic100]

Sorry for your first crash experience.
Luckily there are a few heros here that can help you determining what caused your RTH crash.

I have said it many times and I keep repeating (only as a friendly advise from a pilot who started flying manual drones well before any autonomy was available);

RTH is a fail safe that hopefully will work when it's absolutely needed, not to be used as a normal flight mode, although most people seem to think it is and claim that it is absolutely fool proof because they never had a problem with it. But by far most problems occur during RTH. Wether by wrong settings by the pilot, a GPS or compass interference, obstacles, a low Sun, and maybe even because of a barometer issue while landing.

It is always better and safer to control the drone yourself, after you learned to master it. Manual take off and landing is safer than any algorithm written by a programmer somewhere in China. The amount of variables in a real life environment are countless and no algorithm in a consumer electronics world is capable of dealing with all of them. 99% RTH works ok but you never know when that 1% is up. Same for auto take off and landing.

I've never once manually taken off my drone but I have landed and also caught it manual numerous times. Your saying it's safer to manually fly it up and forget the other buttons don't exist? (I never use RTH so thats not an issue)