Mavic3 Cine crash opinions wanted.

psionic001 · Jan 12, 2023

Hi all.
A colleague had his Mavic3 Cine fail over the water shortly after takeoff.
To me it looks like a total IMU failure. (See below)
I’m trying to get hold of the full Rez file as this one was sent via SMS and pretty low Rez.

IMPORTANT NOTES
1) it was launched from a boat. We’re finding the latest firmware is not as boat proof. Had been operating from the boat for 3 days.

2) it was in ATTI mode (hack) for a week or so with no other issues.

3) on a landing (2 days prior) they couldn’t shut it down by the usual flip method after hand catching, and I believe it ended up upside down on the floor of the boat chipping two props in the process. The broken props were replaced. I’m trying to get more info on this.

VIDEO HERE.

My opinion is IMU fail from the bump.
Or loss of one of the prop blades from an unseen crack.

would love to get some opinions.

Thanks.

mobilehomer · Jan 12, 2023

Let me be the first - PLEASE, post the flight log.

Meta4 · Jan 12, 2023

psionic001 said:
would love to get some opinions.

Opinions aren't worth much unless they are based on the hard evidence that will be in the recorded flight data.

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report of the flight.
Come back and post a link to the report it gives you.
Or .. just post the txt file here.

psionic001 · Jan 12, 2023

Meta4 said:
Opinions aren't worth much unless they are based on the hard evidence that will be in the recorded flight data.

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report of the flight.
Come back and post a link to the report it gives you.
Or .. just post the txt file here.

Aircraft was lost.
Apparently they were using a Pro Controller. Does that have logs on it?
If it has flight logs I’ll get them.
They videoed the controller screen and will be sending that too.

msinger · Jan 12, 2023

psionic001 said:
Apparently they were using a Pro Controller. Does that have logs on it?

Yes, a TXT flight log is created on the remote controller (or mobile device).

psionic001 · Jan 12, 2023

msinger said:
Yes, a TXT flight log is created on the remote controller (or mobile device).

Great. I’ll have access to it within 3-4 days.
Thank you.

HoozierDroneDaddy · Jan 13, 2023

What hack are you using to get ATTI mode?

Yaros · Jan 13, 2023

HoozierDroneDaddy said:
What hack are you using to get ATTI mode?

I don't know which hack OP is using, however I have seen this on YouTube, might help:

Starz · Jan 13, 2023

Yaros said:
however I have seen this on YouTube

That’s funny! Drone speed=wind speed.
Now we can call our drones wind speed indicators!

HoozierDroneDaddy · Jan 13, 2023

Yaros said:
I don't know which hack OP is using, however I have seen this on YouTube, might help:

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Thanks. That must be new. The last time I checked Drone-Hacks.Com they did not have anything for the M3.

psionic001 · Jan 16, 2023

HoozierDroneDaddy said:
What hack are you using to get ATTI mode?

Drone-Hacks, the best way to hack your DJI Drone download their software and plug into the Mav then follow the instructions in the video.

Meta4 · Jan 16, 2023

psionic001 said:
Drone-Hacks, the best way to hack your DJI Drone download their software and plug into the Mav then follow the instructions in the video.

No flight data yet?

HoozierDroneDaddy · Jan 16, 2023

Meta4 said:
No flight data yet?

There site has lots of info and contact for questions on existing or future hacks, etc.

Meta4 · Jan 16, 2023

HoozierDroneDaddy said:
There site has lots of info and contact for questions on existing or future hacks, etc.

No flight data available yet?

psionic001 · Jan 16, 2023

Meta4 said:
No flight data yet?

Hey there.
I got the flight data this morning

DJI Flight Log Viewer - PhantomHelp.com

Had been flying ATTI mode for a-few days before this.
Also note the 4billion MPH data point.

Meta4 · Jan 16, 2023

My plane is boarding now. will look at it tonight.

psionic001 · Jan 16, 2023

Meta4 said:
My plane is boarding now. will look at it tonight.

Thanks man.

Meta4 · Jan 17, 2023

psionic001 said:
Hey there.
I got the flight data this morning

That's a nice place for flying.
The flight data is short but interesting.
How was the drone launched?
Was it hand launched or was it launched from the boat?
If it was launched from the boat, what was the surface it launched from and what might have been close by (within a metre, or under the deck)?

Did the drone appear to be flying faster than it was commanded?
Was it appearing to respond normally to the controls?

psionic001 said:
Also note the 4billion MPH data point.

That's just a data glitch and not related to the incident.

waynorth · Jan 17, 2023

HoozierDroneDaddy said:
Thanks. That must be new. The last time I checked Drone-Hacks.Com they did not have anything for the M3.

The video shows how to change parameters in the drone's firmware/controller. This has been possible for many DJI drones for a long time. It is a free tool from Drone-Hacks, just download their app and connect your drone, then you have access to all the parameters. But it can be hard finding information about the function of all the parameters.

psionic001 · Jan 17, 2023

Meta4 said:
That's a nice place for flying.
The flight data is short but interesting.
How was the drone launched?
Was it hand launched or was it launched from the boat?
If it was launched from the boat, what was the surface it launched from and what might have been close by (within a metre, or under the deck)?

Did the drone appear to be flying faster than it was commanded?
Was it appearing to respond normally to the controls?

That's just a data glitch and not related to the incident.

I was told that the drone is initialised on a table, then transferred to hand, and hand launched.
They cover all the bottom sensors with tape so they can bring it in and land no matter how rough the boat is pitching, and that has been normal ops since the Mav3 was released. Unfortunately we can't turn off downward sensors like the Mav2.
On that flight they put it in ATTI mode to get out to the filming area fast which was about 400 meters away.
They say ATTI mode is a bit faster than sport mode, but it traveled faster than expected.
You guys have seen the video of what the camera did when it lurched over to one side while flying.
They had done a hundred ATTI mode flights before this one, and have done a hundred since with a new cine and had no issues.
They shut the drone down after landing by grabbing it and flipping inverted by hand.
Two days before when they flipped it by hand it bumped a table in the boat and broke two props, but the drone didn't break other than the props got chipped and replaced.
They occasionally get a "can't take off" warning after the motor start up and are idling, but the throttle does not engage.

IMO the Mavic 3 doesn't have any "boat mode" algorithm like other DJI drones in the past, and it probably had a dodgy IMU going bad around the moment of takeoff.