Drone disconnected and crashed

[neco900]

Hi everyone, first-timer here, and English is my second language, so bear with me.

I've been flying for almost 5 years now without issues, but today my drone decided to crash itself into the ground. Everything was fine until it disconnected and started flying sideways until it hit the ground. It disconnected right when it started to go sideways.

It didn't really do much damage; the drone still works, the camera is fine, and the gimbal is fine. I lost 2 propellers, and both of the landing legs broke. Everything else seems to be fine.

The issue is now I'm scared to fly it, thinking it might happen again and cause me to lose the drone completely.

I'm attaching the log as I couldn't really tell what went wrong. I would really appreciate if you guys could check it out.

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[neco900]

I didn't write the model stupid of me, its a mavic 2 pro.

 

[Yorkshire_Pud]

Have a look in MCDatFlightRecords and see if there are any DATs in there, if so upload the one whose name contains FLY097 or something like that.
I would save all the .DATs and .txt flightlogs to computer.
If you have sync'ed your logs the DATs will be gone, if you use an RC1B controller there will be no DATs.

Did you see it descend/fall, if so how rapid was the descent, did it tumble?
Was the battery in the drone or nearby?
Where the broken off propeller bits near the drone?

 

[neco900]

I didn't see it crash tbh i was panicking when it disconnected, the battery was several meters away from the drone, the propellers were on it they are just damaged.

There is actually a lot of DAT files under the folder, the one I'm uploading should be the last flight that it crashed.

 

[zeusfl]

The first flying lot is incompleted. I can't read the second one.

 

[Yorkshire_Pud]

The first flying lot is incompleted. I can't read the second one.

try CsvView, CsvView Downloads

 

[neco900]

Did I do something wrong while uploading it?
The txt file is the one I've used on phantomhelper, the other two is the last two files mentioned in the other folder. 1.8 mb one probably recorded after I recovered the drone if the time stamp is correct.

 

[Yorkshire_Pud]

Did I do something wrong while uploading it?

Both DATs work just fine e.g.

 

[Yorkshire_Pud]

I didn't see it crash tbh i was panicking when it disconnected, the battery was several meters away from the drone, the propellers were on it they are just damaged.

There is actually a lot of DAT files under the folder, the one I'm uploading should be the last flight that it crashed.

Any answers to the questions in post #3 ?

 

[slup]

Mainly... nothing besides one thing is abnormal in this flight.

If looking at 38,2sec into the flight you had already applied a full negative aileron command (right stick fully left)... there you started to also apply a full positive elevator command (right stick fully forward), this places the right stick in the upper left corner at 10 o'clock.

This command should have given a flight path like the one hand-drawn in white in below sat picture, 45 degrees out from the yaw direction, forward & left..? The actual path could be explained if it was a strong head wind... but it was only mild winds which can be confirmed by the small tilt angle when you hovered before you decided to fly sideways to the left.

The roll & pitch together with the combined tilt angle perfectly add up & reaches the max specified 25 degrees... so nothing odd besides the abnormal flight path that the drone actually took.



As you said that the connection disappeared just when it went down... & that the drone continued the sideways path... and down... really suggests a sudden power failure, possibly due to a swelling battery (it was from 2018 apparently).

And I think that the 2 ending errors in the DAT log event stream confirm that...

 

[neco900]

Any answers to the questions in post #3 ?

My bad couldn't make it clear I guess,
I didn't really see it descend it was out of my sight and panicked when I saw it disconnected.

I found the battery several meters away from the drone

The propellers were on the drone, they are damaged but intact.

 

[neco900]

Mainly... nothing besides one thing is abnormal in this flight.

If looking at 38,2sec into the flight you had already applied a full negative aileron command (right stick fully left)... there you started to also apply a full positive elevator command (right stick fully forward), this places the right stick in the upper left corner at 10 o'clock.

This command should have given a flight path like the one hand-drawn in white in below sat picture, 45 degrees out from the yaw direction, forward & left..? The actual path could be explained if it was a strong head wind... but it was only mild winds which can be confirmed by the small tilt angle when you hovered before you decided to fly sideways to the left.

The roll & pitch together with the combined tilt angle perfectly add up & reaches the max specified 25 degrees... so nothing odd besides the abnormal flight path that the drone actually took.

View attachment 171188

As you said that the connection disappeared just when it went down... & that the drone continued the sideways path... and down... really suggests a sudden power failure, possibly due to a swelling battery (it was from 2018 apparently).

And think that the 2 ending errors in the DAT log even stream confirm that...

View attachment 171189

I actually thought the same thing when I found the battery off the drone but it looks fine I'm attaching the pictures of the battery post crash.

 

[slup]

I actually thought the same thing when I found the battery off the drone but it looks fine I'm attaching the pictures of the battery post crash.

The Mavic 2 series is infamous for ejecting the battery on the slightest swelling... both due to that a swelling haven't any free space between the drone & battery to grow in before starting to being pushed out (like the Mavic Pro 1)... & that the battery latches are really poor. We have seen numerous of cases here at the forum.

And that the battery is flat cold doesn't mean that it doesn't swell up when hot...

Or you maybe didn't clip the battery in place properly..?

 

[neco900]

The Mavic 2 series is infamous for ejecting the battery on the slightest swelling... both due to that a swelling haven't any free space between the drone & battery to grow in before starting to being pushed out (like the Mavic Pro 1)... & that the battery latches are really poor. We have seen numerous of cases here at the forum.

And that the battery is flat cold doesn't mean that it doesn't swell up when hot...

Or you maybe didn't clip the battery in place properly..?

I usually double check it before I take off but you never know. Now that you say it battery seems to be a lot dirtier than the drone itself maybe it actually fell off of it?

My actual question is the drone safe to fly with another battery?

 

[slup]

I usually double check it before I take off but you never know. Now that you say it battery seems to be a lot dirtier than the drone itself maybe it actually fell off of it?

My actual question is the drone safe to fly with another battery?

Nobody knows for sure after that free fall, only way to know for sure is to send it in for a check to DJI... up to you if you want to play safe or not.

 

[Yorkshire_Pud]

Nobody knows for sure after that free fall

I crashed a Zoom. MY FAULT.
The obvious damage was a crumpled nose, besides hitting a tree it it also fell 50ft or so and had a hard landing.
Closer inspection revealed a droopy front arm, ( bent pin on the actual pivot ).
Rear arm that lifted in a test flight, ( rotation stop broken off which also meant the arm could be pulled out of the drone, I replaced the arm, I doubt glue would have worked ).
Internal damage, a cracked ciruit board mounting lug, ( araldited and splinted with a shaved matchstick ), and a broken off gimbal mount, ( fixed with an Aradlite impregnated piece of natural fibre string to recreate the 'loop' ), I am proud of that one lol

 

[Yorkshire_Pud]

My bad couldn't make it clear I guess,
I didn't really see it descend it was out of my sight and panicked when I saw it disconnected.

I found the battery several meters away from the drone

The propellers were on the drone, they are damaged but intact.

Can you post a picture of the props?

 

[neco900]

Can you post a picture of the props?

Sure

 

[Yorkshire_Pud]

My bet is both of the damaged blades caught something on the ground, stopped dead and then the other blade came round and smacked into the trailing edge of the stopped blade.

 

[neco900]

I was looking through my flight records and just remembered this almost identical thing happened on an earlier flight, disconnected, started flying sideways but RTH kicked in and saved the day. Don't know if it helps with the case but I'm attaching the records of that flight too.

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