Drone crashed-- not sure what happened

[Arizona Al]

My son was flying our Mavic Pro and it came out of the air at about 120 feet and crashed into the street. Not sure what happened if it was a system problem or operator error. I'll get the unit tomorrow morning and will try to download the logs-- What am I looking for and how do I go about getting the info from both the Mavic and also his Iphone? Any help would be greatly appreciated. We have DJI Care Refresh, but if it was a system problem, I'd like DJI to step up, so need to find out. Thanks in advance for any help!!

 

[msinger]

You can find instructions for retrieving the TXT flight log (from the mobile device) here. See this page for instructions on retrieving the Mavic's internal DAT flight log.

 

[Former Member]

My son was flying our Mavic Pro and it came out of the air at about 120 feet and crashed into the street. Not sure what happened if it was a system problem or operator error. I'll get the unit tomorrow morning and will try to download the logs-- What am I looking for and how do I go about getting the info from both the Mavic and also his Iphone? Any help would be greatly appreciated. We have DJI Care Refresh, but if it was a system problem, I'd like DJI to step up, so need to find out. Thanks in advance for any help!!

Sorry about your crash. I try to get to the bottom of the causes of crashes where the drone just fails mid-flight.

Can you answer a few questions?

Was the battery still in the drone at the crash site? If so, was the drone still powered on? If not, how far from the drone was the battery?

Did the Mavic come straight down vertically or did it descend at an angle?

When it was coming down, do you remember if the motors were on or off?

Was it recording video the whole time up until it hit the ground?

Was there any loss of video or signal before the accident?

 

[Robbyg]

If you suspect it was a power failure we are going to need the DAT file from the Mavic.

How to retrieve a .DAT

Rob

 

[Arizona Al]

You can find instructions for retrieving the TXT flight log (from the mobile device) here. See this page for instructions on retrieving the Mavic's internal DAT flight log.

Thanks, I'll run through those steps when I get the unit tomorrow

 

[Arizona Al]

The battery remained in the Mavic and was still powered up.

It was in an arc and doing oscillations

It seems as motors were on

Camera was on but not recording at the time

No loss of signal and had video the entire time

Here is a Flight record

 

[Arizona Al]

Here is a link to file in Dropbox

Dropbox - FLY096.DAT

Dropbox - FLY097.DAT

I think that will work, let me know if it doesn't

 

[Arizona Al]

Sorry about your crash. I try to get to the bottom of the causes of crashes where the drone just fails mid-flight.

Can you answer a few questions?

Was the battery still in the drone at the crash site? If so, was the drone still powered on? If not, how far from the drone was the battery?

Did the Mavic come straight down vertically or did it descend at an angle?

When it was coming down, do you remember if the motors were on or off?

Was it recording video the whole time up until it hit the ground?

Was there any loss of video or signal before the accident?

The battery remained in the Mavic and was still powered up.

It was in an arc and doing oscillations

It seems as motors were on

Camera was on but not recording at the time

No loss of signal and had video the entire time

 

[BudWalker]

Here is a link to file in Dropbox

Dropbox - FLY096.DAT

Dropbox - FLY097.DAT

I think that will work, let me know if it doesn't

This incident is almost exactly like another incident that I looked at this morning.

Unexplained fall from the sky.

Both this incident and that incident started with noisy gyro data that then caused motorCommanded to be erratic.



As with the other incident this does not seem to be the normal lost or broken prop incident.

@HFMan

 

[Robbyg]

The Info Budwalker gave you is the kind of data you need to show to DJI in order to make sure they step up and acknowledge there is a problem with your Mavic.

Rob

 

[oct]

Mine crashed on sunday, looks like it was the same issue. can someone help me reading the dat files? thx in advance

 

[Robbyg]

Just to put this one to bed, i looked at the Data and just as Budwalker expected it was a Gyro Malfunction. You can see that the pilot pushed up on the throttle and elevator and the Gyro went Haywire. The Props started spinning at all sorts of RPM's to try and compensate for the bad data coming from the Gyro. If you look at the first graph you can see that even when the pilot let go of the sticks the Gyro was still sending out random data and the motors kept trying to compensate.



Rob

 

[oct]

hi all here is my DAT file. I'll be really glad if someone can help me on that.

thx

Dropbox - FLY035.DAT

 

[oct]

here some context:

Same thing happened to me last Sunday (btw my drone arrived Thursday), flying at 120ft from the ground and flew 14min before crash. So glad that didn't fell on anyone or Anything. I have the DAT files but t I don't how to analyze it. I sent my drone to dji already, and the process is being really frustrating so far.

 

[Arizona Al]

My son was flying our Mavic Pro and it came out of the air at about 120 feet and crashed into the street. Not sure what happened if it was a system problem or operator error. I'll get the unit tomorrow morning and will try to download the logs-- What am I looking for and how do I go about getting the info from both the Mavic and also his Iphone? Any help would be greatly appreciated. We have DJI Care Refresh, but if it was a system problem, I'd like DJI to step up, so need to find out. Thanks in advance for any help!!

Well, here is what DJI has come up with in our case

Non warranty per data analysis; SPORTS mode crash FLY096 1.Unit was in SPORTS mode and was responsive to RC input; 2.At t=796.456s, relative height=38.4m, unit recorded external impact, then rolled over and fell. 3.Unit was in SPORTS mode, the vision position sensor can not perform properly. Please refer to manual on factors which can affect vision position sensor performance. Force impact date:05/23/2017 Force impact GPS location:33.2663334 -111.715681 Conclusion: SPORTS mode crash, poor flight environment. No unit malfunction found. [Non warranty Repair]

The only thing we can think of is a possible bird strike.

Now to see how long it will take to get back into the air

Thanks for all the support

Al

 

[BudWalker]

Well, here is what DJI has come up with in our case

Non warranty per data analysis; SPORTS mode crash FLY096 1.Unit was in SPORTS mode and was responsive to RC input; 2.At t=796.456s, relative height=38.4m, unit recorded external impact, then rolled over and fell. 3.Unit was in SPORTS mode, the vision position sensor can not perform properly. Please refer to manual on factors which can affect vision position sensor performance. Force impact date:05/23/2017 Force impact GPS location:33.2663334 -111.715681 Conclusion: SPORTS mode crash, poor flight environment. No unit malfunction found. [Non warranty Repair]

The only thing we can think of is a possible bird strike.

Now to see how long it will take to get back into the air

Thanks for all the support

Al

This is total nonsense. The time offset is different from what DJI reports but that isn't relevant. The Mavic started having problems at 38.4 meters altitude and started thrashing around, including inverted orientation. It wasn't until 4 secs later and the AC had fallen 34 meters that the "external impact" happened. From the Google Earth image it looks like the impact could have been the result of hitting a tree.