Water Crash... Is this the VPS issue im now reading about?

[Egika]

So if he hadn't done down stick, would it just have continued to climb until it reached maximum altitude? What a horrible glitch!

until maximum height or until the sensors cannot detect the water anymore - yes. And this "glitch" is well documented in the manual stating the sensors don't work reliably over water...

 

[Andrew F]

Btw: the Mavic manual clearly states under "Flight Environment Requirements":
"3. Avoid [...] bodies of water"

Must be a new manual. Mine doesn't say that. It says to be careful around the nape of the water.

 

[Robbyg]

I'm not much of an expert but I can see that at 8m 45s the IMU altitude is 23.3ft and the VPS altitude is 17.4ft and at 8m 50s suddenly the VPS altitude drops to 0.7 ft but the IMU altitude raises at 24.6 ft, then at 8m 55s you can see how the VPS reading goes crazy to 22.6ft and two seconds after it reads 0.7ft again. I think that from that moment onwards the VPS readings confused the drone and any descent was interpreted as a landing.

Yes it is very typical of the normal VPS over water problem. Since DJI uses a blanket statement to the effect of "do not fly over water" I am not sure if they have any plans of fixing it, but we can always hope that they do. I also hope the owner has DJI refresh, it seems like a good deal of water got into the Mavic.

The little bit that can be see on log file shows some pretty interesting stuff, I am really hoping he uploads the DAT file.

Rob

 

[msinger]

So if he hadn't done down stick, would it just have continued to climb until it reached maximum altitude?

Yes.

It's not really a glitch. When landing protection is enabled, the Mavic will try to automatically ascend to 0.5 meters when it's below that and it's not landing. Since the downward sensors continued to incorrectly detect the ground, the Mavic kept ascending.

 

[Bunny Too]

Yes it is very typical of the normal VPS over water problem. Since DJI uses a blanket statement to the effect of "do not fly over water" I am not sure if they have any plans of fixing it, but we can always hope that they do. I also hope the owner has DJI refresh, it seems like a good deal of water got into the Mavic.

The little bit that can be see on log file shows some pretty interesting stuff, I am really hoping he uploads the DAT file.

Rob

I am not the most experienced, but you are right, the log file is a very unique read.

 

[Cerberus]

A little off topic question here... how do you guys read the DAT file from another pilot?

 

[Bunny Too]

A little off topic question here... how do you guys read the DAT file from another pilot?

They have to upload to "Dropbox" or similar.

 

[ChasiTail]

It certainly looks like that it was the VPS system.
You are one lucky guy, that it is not sleeping with the fishes

I can see when battery system was under severe stress and it seems like a lot of systems started to crash. I have never seen a log of the systems getting flooded with water.

Can you please please upload the 400mb+ DAT file to a file sharing service so we can see in more detail what happened.
I am going to contact BudWalker because he is the Jedi Master of Log file analysis. I think he will want to personally look at this one. At the very least you will get a very good report of what happened and the community will gain some useful info.

Rob

All that battery stress was after it hit the water. I was getting all kinds of error/warnings on my screen as I was trying to keep it on the surface. I wish I would have had the video recording, it would have been one crazy scene to watch!
Where would I find the DAT file you are talking about? Maybe PM me instructions or a link? I'm not the brightest bulb on this computer upload aspect of things.

 

[msinger]

how do you guys read the DAT file from another pilot?

You can read them with DatCon.

 

[Cerberus]

You can read them with DatCon.

Thanks, this software might be just what I am looking for...

p.s :- I forgot who but someone in here says that auto land can now be cancelled by pushing the stick up, can anyone confirm this?
I'm working at the moment so no way for me to test this for now

 

[msinger]

I forgot who but someone in here says that auto land can now be cancelled by pushing the stick up, can anyone confirm this?

That used to work when running older firmware. In the current version, you must toggle the sport mode switch or disable the "Landing Protection" setting.

 

[ChasiTail]

Btw: the Mavic manual clearly states under "Flight Environment Requirements":
"3. Avoid [...] bodies of water"

that's interesting.. yet on the DJI website for the Mavic, they have promotional videos clearly flying the mavic over water, following a jet ski, filming surfers.. That's a bit odd if they say avoid those areas...


"see everything" and "shooting waves" are the titles to their promo videos.
http://store.dji.com/product/mavic-...dium=cpc&utm_term=mavic pro&utm_content=Mavic Pro&utm_campaign=US - Mavic - Search/BINGSEM#/?_k=6z1mfj

 

[Egika]

yeah, of course many of us have flown over water without issues.
I have been filming kiteboarding many hours for example.
Stating to avoid these areas doesn't mean it can't work or would be forbidden.

Just "avoid" it if you are not sure about it

 

[dewster]

I turn VPS off flying over water. Calm waters, lighting, height could affect VPS.

I guess VPS gets confused like when you're sitting in a stopped car and think that you're moving because a large vehicle moves beside you. It's like vertigo.

 

[Robbyg]

that's interesting.. yet on the DJI website for the Mavic, they have promotional videos clearly flying the mavic over water, following a jet ski, filming surfers.. That's a bit odd if they say avoid those areas...


"see everything" and "shooting waves" are the titles to their promo videos.
http://store.dji.com/product/mavic-pro?utm_source=bing&utm_medium=cpc&utm_term=mavic pro&utm_content=Mavic Pro&utm_campaign=US - Mavic - Search/BINGSEM#/?_k=6z1mfj

DJI is very good at covering their rears from any possible warranty issues. Your one of the few people that have actually retrieved a Mavic that went into the water, I am really hoping that once you dry it out you can retrieve the DAT file.

Hats off to you for the quick work and keeping your nerve. What happened to you is becoming far to common. DJI needs to fix the problem and return the stick up as a means of stopping this from happening. Putting the solution in the sports button is not a good idea, it is just not something most people will think of hitting when they unexpectedly descending into water.

Rob

 

[Bunny Too]

That used to work when running older firmware. In the current version, you must toggle the sport mode switch or disable the "Landing Protection" setting.

Can you just toggle the sport mode switch or do you need dual mode enabled in the menu?

 

[ChasiTail]

yeah, of course many of us have flown over water without issues.
I have been filming kiteboarding many hours for example.
Stating to avoid these areas doesn't mean it can't work or would be forbidden.

Just "avoid" it if you are not sure about it

I guess I had too much faith in the technology that's in the mavic. That's why I bought it, was because of watching & reading all about how amazing the tech was in it and how safe it was to fly and how the sensors did such a great job of making for safe flights.
Unfortunately I didn't read about the bugs over water until after mine went swimming. Nothing in the manual about switching P/S mode to abort a forced landing, nothing about turning off VPS if I dare venture out over water to avoid a false reading from the VPS that would trigger the forced landing. At $1000 a pop, the learning curve is pretty steep & costly should someone encounter one of these situations and not have read online how to cancel that function.

 

[Andrew F]

I turn VPS off flying over water. Calm waters, lighting, height could affect VPS.

I guess VPS gets confused like when you're sitting in a stopped car and think that you're moving because a large vehicle moves beside you. It's like vertigo.

I fly with VPS on over water - which is primarily the ocean - because I want the added safety net in case I get too close. It's easy to lose perspective and I pay attention to all indicators.

 

[Egika]

nothing about turning off VPS if I dare venture out over water to avoid a false reading from the VPS that would trigger the forced landing.

The manual lists the following (using the search term "water"):

• Operate the aircraft with great caution in the following situations - flying over water [...]
• Forward and Downward vision systems may not function properly when flying over water
• The general hint to avoid bodies of water

By stating that the sensors may not function properly, all different things can happen. And that is exactly what you experienced. First the rise and then the automatic landing by full stick down...

I agree with you that DJI did not warn you specifically about what could happen if the VPS went berserk together with a landing protection. The more automated functions they put in to these things, the more combinations of stuff that could happen there are...

 

[Cerberus]

Correct me if I am wrong, but VPS only tries to work when your AC is what, 15 meters above the water?

So wouldn't it be safe to fly over water if you fly your AC more than 15 meters above water with your VPS on?