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New MA Owner But I Don't Have My Drone DJI Does Long Story

spirittoo

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Wellsir ... I got my MA back in March ... only flown it a few times. In April I was about to take it out for a flight, but the app indicated a firmware update was needed. I did the update and the app reported green ready to fly. I took it outside and brought it up to a hover. It jerked a couple of times which I thought was strange. I took it up a couple of more feet in a hover. Without warning the drone flipped on its back and dropped like a rock. The rear arm broke completely.

I sent the drone in under the warranty to dji repair in Texas.. I sent them the information they required. In a couple of days after they received the drone in April , I get an email stating the drone is not covered by the warranty and they wanted $190 to repair it. They never said why the warranty would not cover it.

I called dji which is a 35 min wait on hold. to find out why it was not covered. They told me it was because they did not received the flight records. Longer story short, I had made several attempt to get them the flight records, but they kept claiming they never got them. Finally after several long hold phone calls I asked to speak with a supervisor. I was told one would contact me. None did. Another long wait call. I asked again, this time someone did call in a few day. Got the flight records to them through him.

Over a week later I get an email stating the drone is not cover under the warranty because I had a protective cover on it that blocked the bottom sensor causing the malfunction. I don't believe this. I own several drones and not one of them will flip on their back during a hover. Even if the sensor was covered which is wasn't it should not have done that 10 ft in the air.

I told them if they will not honor their warranty send me the drone back, which is why I have come here for help.
Looking forward to meeting good folks that will help me learn how to take care of my drone.😀
 

copterbob

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Burning question.
What did they think you had the bottom sensor covered with?
Did you have anything additional (not factory) on the bird?
 
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spirittoo

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Burning question.
What did they think you had the bottom sensor covered with?
Did you have anything additional (not factory) on the bird?
Hi spirittoo welcome to Mavic Pilots
Hope you can get thing sorted.
Thank you CYBORG. Once I get my drone back I am looking forward to working with the good folks here to get things together. It has been a couple of days since I told dji to return my drone, but so far I have heard nothing.

Copterbob the only thing I had that was not factory was a red cover instead of the white and the silicone protective cover. None of the sensors were covered. The cover was design for the MA.

Slup if that isn't the record of the flight, then where would I find it? I got that data from the Go4 app on my tablet from the flight records. What do I need to do?:oops:
 

slup

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Thank you CYBORG. Once I get my drone back I am looking forward to working with the good folks here to get things together. It has been a couple of days since I told dji to return my drone, but so far I have heard nothing.

Copterbob the only thing I had that was not factory was a red cover instead of the white and the silicone protective cover. None of the sensors were covered. The cover was design for the MA.

Slup if that isn't the record of the flight, then where would I find it? I got that data from the Go4 app on my tablet from the flight records. What do I need to do?:oops:
First we need to start up with finding the correct .TXT log stored on your mobile device you flew with. We aren't helped by "any" log ... we need the one from the flight where the incident happened.

I've copied in the "how to retrieve" & shortened it a bit here below ... all from the link a gave you earlier. Find the correct one & share it with us either by attaching it directly in a new post here or from your Dropbox as you did earlier.

3. LOG FILE RETRIEVAL

Mobile device DJI TXT logs

The log naming convention, based on the date and time of the start of the flight, is: DJIFlightRecord_YYYY_MM_DD_[hr-min-sec].txt.


With iOS devices running DJI GO 4:

You need to access the app files via computer, either using iTunes or with a file system browser such as iExplorer.

The TXT logs are in Apps » DJI GO 4 » FlightRecord.



With Android devices running DJI GO 4:

The file system should mount when plugged into a Windows machine, or via various software options on a Mac.

The TXT logs are in Internal storage » DJI » dji.go.v4 » FlightRecord.
 

spirittoo

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Here are some pictures of the drone the day of the crash. As you can see I had a red cover and the protective silicone cover. The sensors were not cover. But the arm was damaged.

As you can see in the picture just the arm was damage, but here is a list of parts labor and price dji first sent me.
Item List

Gimbal Axis Arm Module

Quantity: 1

Net Price : 28.00

Total Price: 28.00


Lower Cover Module

Quantity: 1

Net Price : 4.00

Total Price: 4.00


Rear Right Arm

Quantity: 1

Net Price : 10.00

Total Price: 10.00


Upper Decorative Cover (White)

Quantity: 1

Net Price : 1.00

Total Price: 1.00


Front Right Arm (White)

Quantity: 1

Net Price : 13.00

Total Price: 13.00


Upper Cover Module

Quantity: 1

Net Price : 4.00

Total Price: 4.00


Repair Service Fee

Quantity: 2

Net Price : 65.00

Total Price: 130.00



Shipping Cost

0.00


Total Amount

190.00

Just wanted to post this for folks to see the drone the day of the crash. P1040624(1).JPG P1040623(1).JPG P1040749(1).JPG
 

slup

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This is the file of the crash. It happened on the 8th of April. Hopefully this is what is needed.
Something odd is going on with the VPS sensor height ... the barometric sensor reports an ascent from 0-3m height but at the same time the VPS height starts out with 0,1m ... shortly reaches 0,2m during 1,5sec then back to 0,1m & in the end 0m.

But the AC nearly flips as you said ... all starts with a pitch down to about -14 degrees & soon after a roll that ends up to -165 degrees ... during this the AC yaws CW. All this can also indicate a sudden lost of thrust from the left front.

Would like to look at the .DAT log from this flight also ... it ends with FLY033.DAT & you find it in a sub folder called MCDatFlightRecords in the same place you retrieved the .TXT log.
 

slup

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So if we first start to look at the AC movements when thing's start to go haywire ...

At 19,76sec the AC rapidly pitches down (Light blue), this together with a roll going all over in negative direction (Blue) & a yaw that turns CW. This leads to a spiraling rapid descent from 3,89m height to ground. All this indicate as I said earlier, a lost thrust from the left front ... either a motor failure or a lost prop.

As a side note to this we also see that even though the barometric sensor reports a height over HP to 3,89m (Red) the ultra sonic sensor says 0,1m (Black) witch indeed indicates that the sensors were covered or disturbed by the silicon cover ... but even so, that alone can't bring down the AC in this way.

(Click on the charts below to bring them up full screen)

1592471192476.png

Looking further into the motor RPM's show us that something happens with the left front (Magenta) ... at 19,86sec the RPM suddenly drops to only 691rpm's while the others rev between 7700-10300rpm's.

1592472073977.png

Then looking into how the motors was commanded by the flight controller ... As seen below the FC wanted the left front motor to spin 100% (Purple) from 19,75sec. But that only resulted in 691rpm eventually as per chart above.

1592472485464.png

The last check is regarding the motor current draw when all above happens ... at 19,87sec we see that the left front spikes up (blue), indicating it's been jammed.

1592472762335.png

So from above it looks like the reason for this incident was a sudden stop of the left front motor ... either some debris was blown up at take off & into the motor or something internal in that motor came loose & blocked it. Even though something is going on with the downward height sensors (according to the first chart) it can't make a motor stop at height.
 
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JPC

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So if we first start to look at the AC movements when thing's start to go haywire ...

At 19,76sec the AC rapidly pitches down (Light blue), this together with a roll going all over in negative direction (Blue) & a yaw that turns CW. This leads to a spiraling rapid descent from 3,89m height to ground. All this indicate as I said earlier, a lost thrust from the left front ... either a motor failure or a lost prop.

As a side note to this we also see that even though the barometric sensor reports a height over HP to 3,89m (Red) the ultra sonic sensor says 0,1m (Black) witch indeed indicates that the sensors were covered or disturbed by the silicon cover ... but even so, that alone can't bring down the AC in this way.

(Click on the charts below to bring them up full screen)

View attachment 105136

Looking further into the motor RPM's show us that something happens with the left front (Magenta) ... at 19,86sec the RPM suddenly drops to only 691rpm's while the others rev between 7700-10300rpm's.

View attachment 105138

Then looking into how the motors was commanded by the flight controller ... As seen below the FC wanted the left front motor to spin 100% (Purple) from 19,75sec. But that only resulted in 691rpm eventually as per chart above.

View attachment 105139

The last check is regarding the motor current draw when all above happens ... at 19,87sec we see that the left front spikes up (blue), indicating it's been jammed.

View attachment 105140

So from above it looks like the reason for this incident was a sudden stop of the left front motor ... either some debris was blown up at take off & into the motor or something internal in that motor came loose & blocked it. Even though something is going on with the downward height sensors (according to the first chart) it can't make a motor stop at height.
Wow that is an impressive debrief and explanation - opened my eyes to what data records are available.
 

Dakarenduro

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To me, the untrained eye, it would appear likely the left front prop came into contact with the silicon case/top cover. The Airs have very small tolerances between the housing and the props, If that silicone cover came loose or bulged in anyway it could cause the prop to slow or stop spinning completely. anyway, just a theory to explain the crash.
 

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