My bad or not ?

[Mazdaman323lx]

Ok , before we begin , yes I took off with my mini 3 pro before acquiring satellites , however it seem slow to lock in so I figured i'd fly up to 30 m where it would lock on easier and a distance of 100m away.
I was about 80m away , flying away from myself over a wide river , still in atti mode when the drone went left and down at speed despite my up and right stick movements . There was a brief strong wind warning message despite it being a totally windless day before it flew sideways into a wall at speed . Do i have any case for a dji flyaway replacement or am i at fault ? I enclose the flight log and wind chart showing max 6mph wind where I was flying . There's no gps data only stick movements and height distance data to work with . Thanks in advance

 

[slup]

...still in atti mode when the drone went left and down at speed despite my up and right stick movements . ...before it flew sideways into a wall at speed.

Sure about being in Atti mode the whole time? From what you say it sounds like the drone could have suffered from a yaw error due to magnetic interference at power up when you took of without GPS support... the consequence of a yaw error only shows up when the FC tries to hold position & for that to work GPS support is needed. But once the GPS gets a lock later during the flight the full effect of the yaw error will kick in.

I enclose the flight log...

Nope... no log attached.

Do i have any case for a dji flyaway replacement or am i at fault ?

A DJI Flyaway insurance ( if you have that & followed what's needed) will be honored no matter what I think... it's only for you to cough up the $$$.

 

[Mazdaman323lx]

Sorry here is the log

 

[Mazdaman323lx]

Did log attach ? Cant seem to attach txt file

 

[RodPad]

How large is this file?

You might look into this post?

Mavic Flight Log Retrieval and Analysis Guide

With the introduction of the Mavic Mini there has been a noticeable uptick in the number of posts requesting help with lost or crashed aircraft. While there is plenty of help and advice available on this forum, and detailed guidance and options on several other websites, I thought that perhaps a...

mavicpilots.com

Rod ..

 

[Mazdaman323lx]

Ok think i figured it out , see log here DJI Flight Log Viewer - PhantomHelp.com
or

 

[Mazdaman323lx]

I have often flown in atti mode but never experienced such a sudden violent sideways and downwards uncommanded vector , especially against the stick inputs .

 

[Meta4]

I have often flown in atti mode but never experienced such a sudden violent sideways and downwards uncommanded vector , especially against the stick inputs .

Flying in atti mode isn't the problem.
Flying with a yaw error has given the gyro sensor false heading information is a big problem.

The data shows the drone pointing to 342° (just south of west) at startup.
Would this have been correct or was the drone pointing a different direction?
Unfortunately you were using the rudder quite a lot so it's not easy to spot a sudden change of compass direction that would positively ID a yaw error, but the rest of the description of the incident appears consistent.

 

[Mazdaman323lx]

I placed the drone done facing S.W and on lift off turned East . I climbed slowly and away from me . I was 30m up in a wide open area over water so I had plenty of room to maneuver should atti mode cause a drift hence why I didnt wait for the gps home point lock

 

[Yorkshire_Pud]

If you havent already done so DO NOT SYNC YOUR LOGS.
Where you found the .txt flight log have a look in the MCDatFlightRecords folder, there may be .DAT flight logs in there, if so upload the one whose name contains "FLY210" to a file hosting website and make its page public then post the URL here.

 

[MS Coast]

Flying in atti mode isn't the problem.
Flying with a yaw error has given the gyro sensor false heading information is a big problem.

The data shows the drone pointing to 342° (just south of west) at startup.
Would this have been correct or was the drone pointing a different direction?
Unfortunately you were using the rudder quite a lot so it's not easy to spot a sudden change of compass direction that would positively ID a yaw error, but the rest of the description of the incident appears consistent.

Typo somewhere? 342° is just west of north. If the OP's estimate of southwest (225°) and the actual orientation of 342° are correct, there's a 117° difference. That would certainly point to a false gyro sensor heading problem.

 

[Meta4]

Typo somewhere? 342° is just west of north. If the OP's estimate of southwest (225°) and the actual orientation of 342° are correct, there's a 117° difference. That would certainly point to a false gyro sensor heading problem.

Well spotted.
Yes .. that's confirmation that the OP launched with a yaw error which caused the problem.

 

[Yorkshire_Pud]

Flying with a yaw error has given the gyro sensor false heading information is a big problem.

Why would a yaw error cause problems if the drone does not know its location?

BTW I am NOT questioning that there was a yaw error, that seems obvious given the log data and Mazdaman's assertion that the drone was pointing SW at launch.

I see the satellite count reaches 9 but OSD.gpsLevel is never more than 2, doesn't that need to be 3 or perhaps 4 for GPS to be reliable?
OSD.isGPSUsed is FALSE the whole way through the log, as is 'distance'.

 

[slup]

I have often flown in atti mode but never experienced such a sudden violent sideways and downwards uncommanded vector , especially against the stick inputs .

Then you've been lucky & not experienced a yaw error until this flight... imagine that you didn't confirm the drones direction compared to the drone icon on the app map before taking off?

Just out from the .txt log I'm pretty sure that my initial thought was correct... all went good initially in the flight as the FC didn't have to counter wind drift initially (low height), then later couldn't as the drone went into Atti mode ( blue background GPS mode, Pink Atti mode).

But 14,5sec after launch you got 8sats... but even though the FC graded the positional reliability to a 2 (out of 5), it most probably weighed in that data to some extent anyway. Then at 20sec you releases the sticks, but the drone continued to tilt & at 24,8sec all went haywire... & your drone ended up with an 70 degree tilt (combined pitch & roll)... there it couldn't hold the height anymore & the drone speeded away downwards.

If you want us to more exactly confirm the yaw error you need to share the mobile device .DAT log ending with FLY210.DAT.

Why would a yaw error cause problems if the drone does not know its location?

Read the above... & note what happens at 14,5sec.

 

[Meta4]

Why would a yaw error cause problems if the drone does not know its location?

BTW I am NOT questioning that there was a yaw error, that seems obvious given the log data and Mazdaman's assertion that the drone was pointing SW at launch.

I see the satellite count reaches 9 but OSD.gpsLevel is never more than 2, doesn't that need to be 3 or perhaps 4 for GPS to be reliable?
OSD.isGPSUsed is FALSE the whole way through the log, as is 'distance'.

From 15 seconds, shortly after the drone starts to acquire sats the indicated flight mode changes to P-GPS.
At 15.4 sec the roll data changes rapidly and the runaway commences.
Although no location data is displayed, it looks like the drone was working with some tentative location data.

 

[Mazdaman323lx]

So is this my fault or the drones . I often flew indoors through old hangers and tunnels and never had this happen

 

[slup]

So is this my fault or the drones . I often flew indoors through old hangers and tunnels and never had this happen

100% pilot error I'm afraid.

Yaw error but no need for the FC to hold position (nothing external that affects the drone) = nothing happens.
Yaw error with a need for the FC to hold position... the FC will apply thrust on the wrong motors as it have the wrong info about the drones heading direction. With this the positional error grows instead of getting smaller... the FC tries again even more forceful... & everything repeats over & over again ... & the drone flies away, often exceeding both specified speeds & tilt angles.

Might add... this is the main danger with GPS drones, they seems to be flying all by there own & in most cases an ignorant pilot will be saved by the automation. But if the flight controller have the wrong information (from a deflected compass) it will take wrong decisions. ALWAYS confirm that the drone icon on the app map points in the same direction as the drone does in reality before take off... if not POWER down the drone move to another spot & try again.

 

[Meta4]

So is this my fault or the drones . I often flew indoors through old hangers and tunnels and never had this happen

You've powered up the drone somewhere that magnetic interference has deflected the compass so that's its heading information is wrong.
That incorrect heading data has been passed to the gyro sensor for its initial directional information.
When the drone launched and climbed away from the magnetic interference, the compass will have returned to normal and given correct heading information, but the gyro sensor will have continued to give incorrect data.

A check of the drone icon in the Fly app to confirm that the icon was pointing the same way as the actual drone would have identified the problem before launching.
What was the surface you launched from?

 

[Mazdaman323lx]

You've powered up the drone somewhere that magnetic interference has deflected the compass so that's its heading information is wrong.
That incorrect heading data has been passed to the gyro sensor for its initial directional information.
When the drone launched and climbed away from the magnetic interference, the compass will have returned to normal and given correct heading information, but the gyro sensor will have continued to give incorrect data.

A check of the drone icon in the Fly app to confirm that the icon was pointing the same way as the actual drone would have identified the problem before launching.
What was the surface you launched from?

Concrete pier .

 

[MS Coast]

Concrete pier .

There's iron rebar in that concrete.