Crash help

[Eka]

Think this is the file. Have no ide what happened, it just fell down 50m from me.

 

[wardtom084]

Watching...

 

[GFields]

Thanks for sharing!

 

[Eka]

In .txt file in the app i found last message to be "Forced landing", but would be great if someone could analise .dat fie and explain what exactly happened and why. Lots of winds warning i get always and it never forced landing so far.

 

[Meta4]

In .txt file in the app i found last message to be "Forced landing", but would be great if someone could analise .dat fie and explain what exactly happened and why. Lots of winds warning i get always and it never forced landing so far.

There's no hint of a forced landing in the data.
Your flight data doesn't have a lot to work with.
You were flying at full speed in reverse, very low, only 2-3 feet above the ground.
Everything was smooth and stable until the last two lines of data.
At 655 seconds the drone pitched nose-down/tail-up and rolled hard left.
At 655.1 seconds it had spun around and rolled over and the data ends there.

So there's only 0.2 seconds of data to show what happened.
Either the drone lost a prop or it crashed into an obstacle.
The way the data stops so suddenly suggests that the battery was ejected from the impact of a collision.

 

[sar104]

There's no hint of a forced landing in the data.
Your flight data doesn't have a lot to work with.
You were flying at full speed in reverse, very low, only 2-3 feet above the ground.
Everything was smooth and stable until the last two lines of data.
At 655 seconds the drone pitched nose-down/tail-up and rolled hard left.
At 655.1 seconds it had spun around and rolled over and the data ends there.

So there's only 0.2 seconds of data to show what happened.
Either the drone lost a prop or it crashed into an obstacle.
The way the data stops so suddenly suggests that the battery was ejected from the impact of a collision.

The log was properly terminated by the FC on motor stop after impact with the ground. At 655.1 seconds, OSD.groundOrSky goes from Sky to Ground, and OSD.isMotorUp goes from True to False, probably triggered by a roll excursion of +75°.

 

[BudWalker]

The log was properly terminated by the FC on motor stop after impact with the ground. At 655.1 seconds, OSD.groundOrSky goes from Sky to Ground, and OSD.isMotorUp goes from True to False, probably triggered by a roll excursion of +75°.

Just to confirm that there was this in the eventLog stream.
653.744 : 36336 [L-FDI][CTRL]: fault on , tilt_ctrl_fail
653.762 : 36337 [L-FMU/MOTOR] Stop. reason:roll over or atti fail

But, it seems the Mini was losing altitude as it was backing up until it crashed into the ground. That shouldn't have happened since the Mini was in GPS_ATTI and just negative pitch was being applied, i.e. no elevator was being applied. Both relativeHeight and GPS:heightMSL show the Mini dropping 4 meters.

 

[sar104]

Just to confirm that there was this in the eventLog stream.
653.744 : 36336 [L-FDI][CTRL]: fault on , tilt_ctrl_fail
653.762 : 36337 [L-FMU/MOTOR] Stop. reason:roll over or atti fail

But, it seems the Mini was losing altitude as it was backing up until it crashed into the ground. That shouldn't have happened since the Mini was in GPS_ATTI and just negative pitch was being applied, i.e. no elevator was being applied. Both relativeHeight and GPS:heightMSL show the Mini dropping 4 meters.
View attachment 130280

Agreed. But then no one has ever accused a Mini of holding altitude during lateral flight.

 

[Eka]

Thanks everybody for your help. Just to add what it looked like form my prespective. I was going backwards at some 10m above ground and suddenly camera image froze and i even heard props sound stopped since i was just 50m from drone when it happened. I am pretty sure it wasn't flying just few feet above ground. Drone was found and working properly. No prop or any damage at all and it flies without a problem since. Still don't undestand why it was landing while going backward.. But must say i didn't have impression it was landing while flying backwards since i was looking at the screen and it seemed as if it was flying straight back untill image froze.

 

[BudWalker]

Agreed. But then no one has ever accused a Mini of holding altitude during lateral flight.

Yeah, but it reached 0.68 m/s downward velocity - seems a bit much even for a Mini. Are the cynical vibes that I'm getting due to scars sustained in the Mini-deformed-prop wars?

 

[BudWalker]

Thanks everybody for your help. Just to add what it looked like form my prespective. I was going backwards at some 10m above ground and suddenly camera image froze and i even heard props sound stopped since i was just 50m from drone when it happened. I am pretty sure it wasn't flying just few feet above ground. Drone was found and working properly. No damage and it flies without a problem since. Still don't undestand why it was landing while going backward.. But must say i didn't have impression it was landing while flying backwards since i was looking at the screen and it seemed as it was flying straight back untill image froze.

Maybe a small distinction but the Mini wasn't landing. Rather, it was descending when it shouldn't. I.e. the FC didn't conclude landing was necessary because of a low battery or some other reason. The Mini was losing altitude when it shouldn't. There were other points in the flight where altitude was lost or gained when it shouldn't.

The motors stop because of the impact with the ground.

 

[Eka]

Maybe a small distinction but the Mini wasn't landing. Rather, it was descending when it shouldn't. I.e. the FC didn't conclude landing was necessary because of a low battery or some other reason. The Mini was losing altitude when it shouldn't. There were other points in the flight where altitude was lost or gained when it shouldn't.

The motors stop because of the impact with the ground.

Sorry, english is not my native. It wasn't landing but losing altitude for some reason. You are saying it was flying erratically in altiude throughout whole flight? Any idea what could cause such behaviour?

 

[BudWalker]

Sorry, english is not my native. It wasn't landing but losing altitude for some reason. You are saying it was flying erratically in altiude throughout whole flight? Any idea what could cause such behaviour?

There were just a few places where just pitch was applied and there height excursions - both positive and negative. The one leading to the crash was a little more extreme.

Don't know the cause. My Mini doesn't do this. The Mini has a history of uncommanded descents being caused by deformed props. Put another way the FC algorithms made the wrong decision in favor of descending instead of slowing forward progress. That same defect may be the cause of the behavior you are seeing.

 

[Meta4]

Just to add what it looked like form my prespective. I was going backwards at some 10m above ground and suddenly camera image froze and i even heard props sound stopped since i was just 50m from drone when it happened. I am pretty sure it wasn't flying just few feet above ground.

Here's what the data shows.
At 597 seconds you brought the drone down from >10 metres and flew around at 3-4 metres above the ground for about two minutes.
You did not touch the left stick after 597 seconds.

At 651.1 seconds the altitude sank below 3 metres and kept getting lower until the last data point showed 0.6 metres at 655.1 sec.

 

[Eka]

So to conclude: For some reason aircraft sank few meters by itself while i was giving it command to fly backward without any other input untill it reached ground level and crashed probably into corn plant since they were growing some 0.5m high on that feild. From what i read so far it could be bent prop, wind or something else yet to be discovered. Since then i was flying it with original props and no problems so far. Thanks everybody for your help.

 

[Eka]

In .txt file in the app i found last message to be "Forced landing", but would be great if someone could analise .dat fie and explain what exactly happened and why. Lots of winds warning i get always and it never forced landing so far.

You can ignore this post since i was looking at wrong file. Sorry about this. There is NO info of forced landing in this flight .txt.