Series of odd alarms... fell to earth

[MVP-PDX1]

Hello Everyone,

My MP encountered a series of unusual errors and then immediately fell out of the sky. It appears that something went wrong with the battery in flight. As soon as I saw the first alert, the drone was losing altitude and heading back towards the home point. I had no control over the AC. All I could do was wonder WTF and watch it fall.

Now, I've looked up some info on the errors. This was a new battery with less than 10 or so charges. I'd flown for several minutes prior to the event, hard to believe that all of the sudden 4 minutes into flight in sport mode, that any propeller would randomly come flying off. And why would a battery error suddenly cause a rotor to eject. As soon as the first battery message popped up, I lost any ability to regain control of the AC. Any ideas here, guys? I'm hoping DJI steps up to the plate here and make things right. Anyone have any comments on the flight data?


Problem?

During a normal flight the following errors popped up out of nowhere. Drone lost control and spun to the ground.

Battery:Overcurrent During Discharge; Speed Error
Motor Current Error. Check your propellers and fly with caution.; Speed Error
GPS Position NoMatch
Speed Error
Compass Error
Motor Idling (Propeller Loose or Missing); Compass Error


Was unit in a crash?

Yes.

What have you tried so far?

Uploaded the flight log for analysis. DJI Flight Log Viewer - PhantomHelp.com


What device are you using ( iphone , ipad, Samsung , etc)?

Iphone 7+

What firmware are you running ( aircraft, remote controller)?

The release prior to current.

What Go app version are you using?

DJI Go 4

Any modification? (if so what)

Vinyl, forward facing body wrap.

Did you change anything or install any apps? (if so what)

Nothing.

Do you have a video or pictures of the problem? (if so post link)

 

[msinger]

Where were all of the props when you found your Mavic?

 

[tcope]

Appears to me at 4m11.2s that is starts to free fall. At that point it appears that it is registering at least one motor's speed that is not correct. As indicated below, it appears that the Mavic threw a propeller. it went another 60' after that so I'd think that the prop would not have been very close to the crash sight.

 

[MVP-PDX1]

Where were all of the props when you found your Mavic?

All four rotors we're present. Two on the left side were still attached. The two on the right side appeared to have broken off during impact.

 

[Kilrah]

So you really had all blades there and not one part missing?

 

[MVP-PDX1]

Appears to me at 4m11.2s that is starts to free fall. At that point it appears that it is registering at least one motor's speed that is not correct. As indicated below, it appears that the Mavic threw a propeller. it went another 60' after that so I'd think that the prop would not have been very close to the crash sight.

The AC hit the pavement when it crashed, two lane road. Everything was collected within the area of those two lanes.

 

[MVP-PDX1]

So you really had all blades there and not one part missing?

I have the blades. Parts missing were the bottom of the rear motor.

 

[MVP-PDX1]

So you really had all blades there and not one part missing?

Yes. However, I just noticed that on the back of one of the rotors is missing all three locking prongs.

 

[msinger]

Are those OEM DJI props?

 

[MVP-PDX1]

Are those OEM DJI props?

Yes, I think they're 8331 model. DJI part number.

 

[msinger]

Does your Mavic still power on? If so, we can get some additional information from the DAT flight log. You can retrieve it from your Mavic like this. If it's too large to attach here, upload it to a file sharing site like Dropbox and post the download link back here.

 

[gnirtS]

Any birds around it?

 

[MVP-PDX1]

Any birds around it?

None. Was in close visual range too.

 

[Aww@Mavic]

This didn't happen after a firmware update did it?
I recently stopped updated due to the horror stories on here that use the words 'firmware update' and 'catastrophic failure' to many times in the same thread!
I have now adopted the 'if it's not broke, don't try and fix' approached...
I hope DJI step up and resolve your issue promptly

 

[MVP-PDX1]

Does your Mavic still power on? If so, we can get some additional information from the DAT flight log. You can retrieve it from your Mavic like this. If it's too large to attach here, upload it to a file sharing site like Dropbox and post the download link back here.

Yes, it powers on. Surprisingly, even the camera still works with the exception of the gimbal. Here is the dat file.

 

[sar104]

Yes, it powers on. Surprisingly, even the camera still works with the exception of the gimbal. Here is the dat file.

That's not the correct DAT file - that was created on August 1, while the flight was on July 29. You need to look earlier. And we do need to see the DAT file, because the txt log is not conclusive:



Something clearly goes wrong at 251 s into the flight, and it led to an initial CCW yaw with moderate pitch and extreme roll excursions, followed by some attitude stabilization, and then a rapid CW spin. The spin is characteristic of loss of propulsion from one of the CW motors, i.e. front left or back right. To determine exactly what happened requires a look at the motor speed and motor current data from the DAT file.

 

[BudWalker]

Yes, it powers on. Surprisingly, even the camera still works with the exception of the gimbal. Here is the dat file.

This isn't the correct .DAT. FLY049.DAT is the correct one. This is shown in CsvView

 

[MVP-PDX1]

This didn't happen after a firmware update did it?
I recently stopped updated due to the horror stories on here that use the words 'firmware update' and 'catastrophic failure' to many times in the same thread!
I have now adopted the 'if it's not broke, don't try and fix' approached...
I hope DJI step up and resolve your issue promptly

No, I was running the release prior. I agree with the NB = DFix policy. I started down the path with DJI, but honestly my flight time and photography is too important to play the waiting game, only to find out it's all billable. Even if I didn't have them do the repair and had them send it back to me, I'm still out $65 for diagnosis and log evaluation. I've already ordered the replacement parts. The left rear arm came today and I've got that installed. Working on the new upgraded gimbal mount right now. The remaining parts come tomorrow and hopefully after a little re calibration, she'll fly again.

 

[MrsTreat]

No, I was running the release prior. I agree with the NB = DFix policy. I started down the path with DJI, but honestly my flight time and photography is too important to play the waiting game, only to find out it's all billable. Even if I didn't have them do the repair and had them send it back to me, I'm still out $65 for diagnosis and log evaluation. I've already ordered the replacement parts. The left rear arm came today and I've got that installed. Working on the new upgraded gimbal mount right now. The remaining parts come tomorrow and hopefully after a little re calibration, she'll fly again.

Good luck. You’re doing the right thing.