DJI Refresh *doesn't* cover sunk drones!?

[AnotherMavicPilot]

It's a fair distance 30 yards at least. And that's a private dock I can't get on to. I appreciate the straw clutching.

Maybe try contacting a local scuba company, explaining your situation and see if they may be able to help or give you advice.

I really feel for you man, I hope you're able to get something sorted.


Best of luck to you!

 

[sar104]

Just to illustrate @msinger's explanation, you can see the switch in flycState to "Forcedlanding" after you applied full down throttle while the VPS system was reporting a height of less than one meter.

 

[Shawn King]

Maybe try contacting a local scuba company, explaining your situation and see if they may be able to help or give you advice.

Yup - emails already sent. But a salvage diver will likely cost $250+. I don’t have $250+.

I really feel for you man, I hope you're able to get something sorted.


Best of luck to you!

Thanks! I started a Support Ticket with DJI but I'm not hopeful.

 

[MichiganMavic]

Nothing to do with the thread , but I have to say that every time I see these threads with the flight info broken down to the minute stick inputs, it just shows the high intelligence of some members in this Forum.
It also shows that this Hobby has nothing to do with Kids and Toys like a lot of uninformed people think. I appreciate the things I learn from you guys that help others in here.
Great job guys ( msinger, sar104, Thunderdrones, just to name a few) that’s what makes people come here and stay [emoji106].

 

[Shawn King]

Just to illustrate @msinger's explanation, you can see the switch in flycState to "Forcedlanding" after you applied full down throttle while the VPS system was reporting a height of less than one meter.

Thanks. Interesting graph - what I can understand of it. Would you mind helping me figure out some stuff?

Could you define "flycState" and "the VPS system"? What does "OSD" stand for?

That's a start...

 

[sar104]

Thanks. Interesting graph - what I can understand of it. Would you mind helping me figure out some stuff?

Could you define "flycState" and "the VPS system"? What does "OSD" stand for?

That's a start...

"flycState" is a numeric representation of the aircraft flight mode. 1 is ATTI, 6 is P-GPS, 11 is auto takeoff and 33 is forced landing, to give a few examples.

VPS is the vision positioning system that includes the bottom sensors that generate the sWaveHeight values.

OSD is just a field prefix in the log files - I think it stands for "On screen display".

 

[sar104]

With regard to the log, there are a couple of things that still bother me. It appears to have shut down the motors in mid-air - perhaps because the VPS system was not detecting descent - and the "OSD.groundOrSky" flag is set to "Sky" right up to the end of the log. Normally the flight log shows "Ground" before the recording ends. The last recorded barometric altitude is well above zero.

So while it was arguably pilot error, you may have a case to make with DJI that the motors should not have shut down. I'd need to see the mobile device DAT log in order to be sure though.

 

[AnotherMavicPilot]

With regard to the log, there are a couple of things that still bother me. It appears to have shut down the motors in mid-air - perhaps because the VPS system was not detecting descent - and the "OSD.groundOrSky" flag is set to "Sky" right up to the end of the log. Normally the flight log shows "Ground" before the recording ends. The last recorded barometric altitude is well above zero.

So while it was arguably pilot error, you may have a case to make with DJI that the motors should not have shut down. I'd need to see the mobile device DAT log in order to be sure though.

I like the sound of this, a glimmer of hope perhaps?

Keep us posted OP, we've all got our fingers crossed for you!

 

[AnotherMavicPilot]

With regard to the log, there are a couple of things that still bother me. It appears to have shut down the motors in mid-air - perhaps because the VPS system was not detecting descent - and the "OSD.groundOrSky" flag is set to "Sky" right up to the end of the log. Normally the flight log shows "Ground" before the recording ends. The last recorded barometric altitude is well above zero.

So while it was arguably pilot error, you may have a case to make with DJI that the motors should not have shut down. I'd need to see the mobile device DAT log in order to be sure though.

A bit OT here so please excuse me, but have you thought about doing a log reading tutorial/guide? You'd obviously be the perfect person for the job and the information you provided would be invaluable to the drone community, it's just a suggestion.

I know something like that would take a lot of time to put together, but would be immensely helpful to all at MavicPilots.

 

[Kilrah]

You don't necessarily land where you took off, so the system must consider landing at non-zero height as normal.

When close to ground and in an automatic landing procedure the VPS is the right primary height source to be looking at. Unfortunately in OP's environment the VPS was giving garbage, and garbage that actually looks very much like a genuine landing so that it couldn't even be flagged as invalid.

Looks like one of them rare "all the bad things aligned" case.

 

[ColinF]

Yes.


No. You need to move the throttle to the full up position to cancel the auto landing (just like you would do when your drone is landing near the ground).

Feel very badly for the OP, but, this is really good information for others who may not be aware of what to do and not to do in a similar situation.

 

[sar104]

You don't necessarily land where you took off, so the system must consider landing at non-zero height as normal.

When close to ground and in an automatic landing procedure the VPS is the right primary height source to be looking at. Unfortunately in OP's environment the VPS was giving garbage, and garbage that actually looks very much like a genuine landing so that it couldn't even be flagged as invalid.

Looks like one of them rare "all the bad things aligned" case.

Yes - but the barometric altitude was still decreasing rapidly, and yet it seems to have ignored that. Unless we have huge latency going on here the splash down cut off the log.

 

[sar104]

A bit OT here so please excuse me, but have you thought about doing a log reading tutorial/guide? You'd obviously be the perfect person for the job and the information you provided would be invaluable to the drone community, it's just a suggestion.

I know something like that would take a lot of time to put together, but would be immensely helpful to all at MavicPilots.

I've been trying to finish one for nearly two years now. It's really rather pathetic, but I can't seem to get it into a satisfactory state. Possibly just needs more people to keep bugging me about it, so thanks.

 

[Shawn King]

"flycState" is a numeric representation of the aircraft flight mode. 1 is ATTI, 6 is P-GPS, 11 is auto takeoff and 33 is forced landing, to give a few examples.

VPS is the vision positioning system that includes the bottom sensors that generate the sWaveHeight values.

OSD is just a field prefix in the log files - I think it stands for "On screen display".

Thanks for the definitions. Parsing it out makes it look (sadly) exactly what msinger told me. It was an (ugly) confluence of events - light fog confused the downward facing sensors AND I had "Landing Protection" turned on AND I was going full throttle down for a (short) period of time. That caused the drone to go into "Forced Landing" mode. If I had known that's what it was doing (there was no indication on screen and no beeping/vibration from the Remote Controller and/or iPhone that it was forcing itself to land) and "simply" throttled up, it would have stopped. Instead, as I saw it heading down (at high speed!) I took my hands off the controls, thinking that would make it stop.

Sigh....now I wait for the DJI Support Ticket to make its way through their system. Wish me luck...

 

[Shawn King]

With regard to the log, there are a couple of things that still bother me. It appears to have shut down the motors in mid-air - perhaps because the VPS system was not detecting descent - and the "OSD.groundOrSky" flag is set to "Sky" right up to the end of the log. Normally the flight log shows "Ground" before the recording ends. The last recorded barometric altitude is well above zero.

While I barely understand that in detail, it does not sound good.

So while it was arguably pilot error, you may have a case to make with DJI that the motors should not have shut down.

Interesting.

I'd need to see the mobile device DAT log in order to be sure though.

Happy to send it to you or post it here if you think it will help (and point me to where I'd find those files). Even from a forensic point of view.

 

[Shawn King]

Keep us posted OP, we've all got our fingers crossed for you!

Will do and thanks!

 

[Shawn King]

Looks like one of them rare "all the bad things aligned" case.

You have no idea how much that accurately reflects my life in general!

 

[sar104]

Happy to send it to you or post it here if you think it will help (and point me to where I'd find those files). Even from a forensic point of view.

Mobile device DAT file: How to retrieve a V3.DAT from the tablet

You are looking for the file FLY055.DAT

 

[Shawn King]

Feel very badly for the OP, but, this is really good information for others who may not be aware of what to do and not to do in a similar situation.

In many circumstances, my life has served as a bad example to others. This is just one more thing...

 

[Kilrah]

Yes - but the barometric altitude was still decreasing rapidly, and yet it seems to have ignored that.

Indeed, it could be looking at baro vertical speed and at least checking it's not anywhere near what the current stick order would command. Seems that when they switch to landing mode they look at nothing other than the VPS.

Saying whether it should would require deeper investigation, there could be side effects.