disaster...crash what on earth happened? any ideas?

[kugaman1]

Hi all, thank you for accepting me as a new member.

On my second ever flight, my drone crashed itself today. Its a phantom 4.

Heres my flight log.

HealthyDrones.com - Innovative flight data analysis that matters

Was flying my phantom 4 for the 2nd ever time and it suddenly decided to veer off course and smash into a concrete tower! The drone was only a few hundred yards away and there were no sources of interference.

I have no idea what happened, but looking at a replay, there was no control stick input at this point, it just veered away on its own!!!

The wind was minimal, had a good signal, good gps, latest firmware, IMU, compass, gimbal all calibrated...

What on earth happened?

I have a replay that shows there was no control input when the drone decided to do a big loop and smash into the tower, but Im not sure how to upload that.....

Very confused.

Any input appreciated.

Will try DJI tomorrow to see what they are saying......

 

[F3honda4me]

Please get the DAT file from the drone itself and upload to Dropbox then link here. Be sure to choose the DAT just for this flight. How to retrieve a .DAT

 

[kugaman1]

Ok, it took a while, but heres the file!

Had a look at it earlier, but no sign of any issues!

Uploadfiles.io - fly017.dat

 

[F3honda4me]

Ok, it took a while, but heres the file!

Had a look at it earlier, but no sign of any issues!

Uploadfiles.io - fly017.dat

Ok I'm downloading it now. Dropbox is a lot faster for future reference. I can get a file this size from dropbox in seconds, this site is going to take 10 minutes. :/

 

[F3honda4me]

Based on what I see in the logs, you either had a major hardware failure, or there was large interference where you flew. What is that huge concrete tower exactly? I wonder if that caused interference of some kind? The first time I see error in the log was actually the first time you flew very close to the concrete tower. From there on out you get a lot of compass/gps errors and even a barometer error.

I would definitely send this to DJI though.

66.520 : 821368950 : 8836 [L-GPS](0)Lost. Reason:compass yaw err large
66.740 : 822358966 : 8847 [L-GPS](0)Lost. Reason:gps disable
67.320 : 824968606 : 8876 [L-GPS](0)Lost. Reason:compass yaw err large
67.540 : 825959122 : 8887 [L-GPS](0)Lost. Reason:gps disable
67.920 : 827668605 : 8906 [L-GPS](0)Lost. Reason:compass yaw err large
69.120 : 833069095 : 8966 [L-GPS](0)Lost. Reason:gps disable
369.560 : 2185048869 : 23988 [L-GPS](0)Lost. Reason:compass yaw err large
373.740 : 2203858977 : 24197 [L-GPS](0)Lost. Reason:gps disable
389.140 : 2273159255 : 24967 [L-GPS](0)Lost. Reason:gps yaw err large
399.120 : 2318068973 : 25466 [L-GPS](0)Lost. Reason:gps disable
399.740 : 2320858973 : 25497 [L-GPS](0)Lost. Reason:compass yaw err large
400.139 : 2322658567 : 25517 [L-GPS](0)Lost. Reason:gps disable
402.132 : 2331622636 : 25616 [L-NS][AHRS] yaw aligned 0
405.340 : 2346059208 : 25777 [L-GPS](0)Lost. Reason:gps velocity err large
406.401 : 2350833454 : 25830 [L-FDI][FDI][CTRL]: fault on , horiz_ctrl_fail
407.940 : 2357759100 : 25907 [L-GPS](0)Lost. Reason:gps disable
408.081 : 2358393981 : 25914 [L-FDI][FDI][CTRL]: fault off, horiz_ctrl_fail
413.740 : 2383859101 : 26197 [L-GPS](0)Lost. Reason:gps yaw err large
415.781 : 2393044075 : 26299 [L-FDI][FDI][CTRL]: fault on , horiz_ctrl_fail
421.780 : 2420039212 : 26599 [L-FDI][FDI][NS(0)][BARO(0)]: fault on , abrupt
421.819 : 2420218008 : 26601 [SWITCH][NS]req:fdi,0to0,reason:baro.abrupt,result:fail for same index
421.820 : 2420218909 : 26601 [L-FDI][FDI][NS(0)][BARO(0)]: fault off, abrupt
421.860 : 2420402787 : 26603 [L-FDI][FDI][CTRL]: fault on , tilt_ctrl_fail

 

[kugaman1]

Based on what I see in the logs, you either had a major hardware failure, or there was large interference where you flew. What is that huge concrete tower exactly? I wonder if that caused interference of some kind? The first time I see error in the log was actually the first time you flew very close to the concrete tower. From there on out you get a lot of compass/gps errors and even a barometer error.

I would definitely send this to DJI though.

66.520 : 821368950 : 8836 [L-GPS](0)Lost. Reason:compass yaw err large
66.740 : 822358966 : 8847 [L-GPS](0)Lost. Reason:gps disable
67.320 : 824968606 : 8876 [L-GPS](0)Lost. Reason:compass yaw err large
67.540 : 825959122 : 8887 [L-GPS](0)Lost. Reason:gps disable
67.920 : 827668605 : 8906 [L-GPS](0)Lost. Reason:compass yaw err large
69.120 : 833069095 : 8966 [L-GPS](0)Lost. Reason:gps disable
369.560 : 2185048869 : 23988 [L-GPS](0)Lost. Reason:compass yaw err large
373.740 : 2203858977 : 24197 [L-GPS](0)Lost. Reason:gps disable
389.140 : 2273159255 : 24967 [L-GPS](0)Lost. Reason:gps yaw err large
399.120 : 2318068973 : 25466 [L-GPS](0)Lost. Reason:gps disable
399.740 : 2320858973 : 25497 [L-GPS](0)Lost. Reason:compass yaw err large
400.139 : 2322658567 : 25517 [L-GPS](0)Lost. Reason:gps disable
402.132 : 2331622636 : 25616 [L-NS][AHRS] yaw aligned 0
405.340 : 2346059208 : 25777 [L-GPS](0)Lost. Reason:gps velocity err large
406.401 : 2350833454 : 25830 [L-FDI][FDI][CTRL]: fault on , horiz_ctrl_fail
407.940 : 2357759100 : 25907 [L-GPS](0)Lost. Reason:gps disable
408.081 : 2358393981 : 25914 [L-FDI][FDI][CTRL]: fault off, horiz_ctrl_fail
413.740 : 2383859101 : 26197 [L-GPS](0)Lost. Reason:gps yaw err large
415.781 : 2393044075 : 26299 [L-FDI][FDI][CTRL]: fault on , horiz_ctrl_fail
421.780 : 2420039212 : 26599 [L-FDI][FDI][NS(0)][BARO(0)]: fault on , abrupt
421.819 : 2420218008 : 26601 [SWITCH][NS]req:fdi,0to0,reason:baro.abrupt,result:fail for same index
421.820 : 2420218909 : 26601 [L-FDI][FDI][NS(0)][BARO(0)]: fault off, abrupt
421.860 : 2420402787 : 26603 [L-FDI][FDI][CTRL]: fault on , tilt_ctrl_fail

Cool. Thanks for this. I couldnt use dropbox as they wanted me to open an account for £10 a month!

Looks like there was a serious issue!

Hopefully DJI will be accomodating tomorrow!

Thanks again.

Andy

 

[Neon Euc]

[QUOTE="kugaman1,?

I have a replay that shows there was no control input when the drone decided to do a big loop and smash into the tower, but Im not sure how to upload that.....

[/QUOTE]

Any chance it went around the tower, lost signal then done an automatic RTH going a straight line back to the home point and crashed into the tower?



Neon Euc

 

[kugaman1]

Sorry, should add, its an old reform tower, used as a monument for religious significance.

There are no electronics or anything associated with it.

 

[F3honda4me]

Any chance it went around the tower, lost signal then done an automatic RTH going a straight line back to the home point and crashed into the tower?



Neon Euc

No

 

[kugaman1]

Sorry, should just add, as my wife pointed out, its actually a granite tower, not concrete!

As f3hondatime4me points out, there was no loss of signal, it never flew around the back of the tower, it was flying fine then just suddenly veered off and crashed!

 

[DocDiggler]

Hm that made me think
Do you know depending on the sort of granite they can contain magnetic minerals and also emitting very small amounts of radiation now this might not sound much but I can see a massive structure there and a small phantom with high sensitive electronics
Also everything seems to be fine before you got close to it
I might be wrong just a sort


Sent from my iPad using PhantomPilots

 

[DocDiggler]

Thought


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[With The Birds]

Did you attempt any stick inputs to avoid the collision? I know you say no inputs are recorded in the log but did you try anything? 'This is bizarre as the depicted flight path shows you successfully flying past it earlier.

It might be the compass was providing strange readings to the FC and GPS was ignored as a result with the AC drifting into the structure (no position hold).

 

[kugaman1]

no mate, didn't try anything.

was flying fine, heading towards tower then stopped and turned away.
Next thing it just did a big loop and smashed into the tower, no time to react!

bit of a nightmare really!

 

[kugaman1]

Not a lot to update today....apart from the fact that its very annoying to have to queue for DJI online chat only for them to disappear and not respond half way through the conversation!
Eventually got hold of them on the second attempt after waiting for 35 minutes!
Anyway, they've given me an email address to send the details to. Ive done that so hopefully they will contact me soon with regards to returning it for investigation.
will let you know how it goes!!!

 

[Filmmaker]

Do you happen to have a video of the incident? Did you receive any errors during the flight? What I find strange is the flipping part. I've seen a Phantom 4 flip twice but that was due to prop catching on to something. Even without a gps and errors with barometer you should have seen only drift and altitude shifts. However, that shouldn't cause IMU's fatal gyro malfunction which most likely is the only possible cause of a drone flipping. On top of that there are two IMU's in Phantom 4 so it's highly unlikely that both of them just failed.


Sent from my iPad using PhantomPilots

 

[kugaman1]

Hi mate, not sure why you think it flipped? It didnt!
When I said it did a big loop, I meant in a horizontal plane, not a vertical one!

It flew round in a loop and hit the tower.

It filmed to the point where everything went haywire, then the film stopped, so no film of the impact which was a second or so later.

Just waiting for an email back from DJI to arrange a return of the drone!

 

[With The Birds]

You say the wind was minimal. Healthy drones records 22ms gusts (close to 80km/hr) around the structure. That should be enough to blow the AC into it. I noticed the whole flight looked pretty erratic, the wind would explain it.

 

[Filmmaker]

Sorry mate, I thought you were talking about vertical loop. I'm almost certain you are victim of that tower which caused switch to ATTI mode and the drift towards the tower. In ATTI mode even the slightest breeze causes considerable drift. With heavy gusts your drone becomes a kite.


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[kugaman1]

Hmm, there really werent any gusts.

The flight was maybe erratic as it was my second ever flight so I was taking it steady and being methodical when changing direction etc.

As you can see from the posts above, all was ok until the major gps/compass errors which occured at the exact time of the crash.

Everything was under control until it decided to go haywire! From the way it flew in a loop, I really dont think it was down to wind as at some points it was flying into the wind!