Crashed into tree and then into water. Controller disconnected

[gvsukids]

Took off from a dock with full battery. Flew around for a few minutes, had 2 app disconnections which didn't happen when I flew much further. Then flying it towards shore as I was walking with it through some trees away from launch point, the controller disconnected as I was about 100 feet away from drone in perfect vision. Then the drone returned to home landing in a tree, even with sensors on. Then trying to get it out of tree it fell onto dock and into water. Quickly retrieved and removed battery.

I'm wondering why the controller disconnected so close by. Is there information in the app I can retrieve to help?

 

[Drone-Retriever]

If you want to save a drone from water immersion take a look at www.drone-retriever.com to learn about What Actually Happens to a Drone After a Water Event.
Hope this helps.

 

[gvsukids]

Thanks for the advertisement and not anything useful to my question

If you want to save a drone from water immersion take a look at www.drone-retriever.com to learn about What Actually Happens to a Drone After a Water Event.
Hope this helps.

 

[WithTheBirds]

It hit the tree canopy doing the ascend to RTH height?

 

[WithTheBirds]

Thanks for the advertisement and not anything useful to my question

Fair call...

 

[MAvic_South_Oz]

Thanks for the advertisement and not anything useful to my question

Well you didn’t specifically ask for help on drying out your drone etc, but that page does have heaps of info on the best process to do so.
Scroll down a bit.

Post up your flight logs and that may reveal some aspects of the flight as to the disconnections.

It is certainly possible your auto return to home did take it up into tree canopy.
It’s a common trap when flying low and in forested areas.
Low and trees block signals.

 

[WithTheBirds]

Well you didn’t specifically ask for help on drying out your drone etc, but that page does have heaps of info on the best process to do so.
Scroll down a bit.

Post up your flight logs and that may reveal some aspects of the flight as to the disconnections.

It is certainly possible your auto return to home did take it up into tree canopy.
It’s a common trap when flying low and in forested areas.
Low and trees block signals.

Best process?

 

[MAvic_South_Oz]

Best process?

A well thought out process and lots of good ancillary info.
I take it you read it through ?

 

[DanMan32]

One reason I figured it would be a nice feature to have flight profiles with all the settings stored in the profile. Even better would be to have the ability to export the profiles.

You can have your standard profile, one for indoors, one for outdoors with canopy.

Besides using the profile for different flight environments, it can be used to be sure you have all your settings after firmware update.

 

[GerdS]

I had a few controller disconnects with my Mavic Pro some time ago. Usually this is caused by problems of your smart device (phone or tablet) or USB cable. The controller firmware can totally freeze in such situations while its display still shows valid data. Usually it helps disconnecting the smart device and then power-cycling the controller to get control back. You can check for a bad USB cable by using a standard USB cable (e.g. the charging cable delivered with your smart device) and if the problem doesn't show up again, then replace the DJI cable with a new one.

And I hope you have learned something from this accient.
1. Choose your takeoff location carefully with a possible RTH in mind.
Don't takeoff under obstacles to the sky, such as trees or roofs.

2. Ensure you have set your RTH altitude high enough within GO4. I am using 40m which is sufficient in most cases, at least more high than the highest trees.

 

[WithTheBirds]

A well thought out process and lots of good ancillary info.
I take it you read it through ?

There is a difference between well thought out and best. There are numerous technical inaccuracies of varied potential significance however the main likely issue is that it is over enthusiastic.

The process described for salt water immersion has close to zero prospects of being effective for the longer term (assuming it gets the drone flying in the first instance).

The dunk in a bucket and hope for the best method has a surprising initial success rate. Even with cameras and mobile phones. The fun is short lived however. Sea water isn't a "mild corrosive" (corrosive liquids have Ph significantly higher or lower than that of sea water and are demonstrated to destroy biological tissue on contact) it does however accelerate the corrosion (rusting) process. This is because sea water is, contrary to what is suggested, actually a quite good electrical conductor. It can provide for significant enough unintended current flow within the immersed device to permanently damage electronics, even before the cleaning process is initiated. Mavic batteries are definitely not sealed against moisture ingress and the motors don't contain bushings (they use shielded bearings) with silicon steel laminations for the stator poles. The fact the magnet wire is coated has nothing to do with the fact the coils are wound tightly. I think I stopped reading somewhere around that point.

 

[MAvic_South_Oz]

I totally agree about salt water immersion and mid to long term ending.
Personally I could never trust such and flying computer ever again in the air after a dip.
Let’s not drag to OPs post off track with further discussion about the drone retriever info.
There are a few things there I was not in total agreement with, but on the whole about equal to anything else with the rinse / isopropyl type of process I’ve seen online.
Ha ha, better than bags of rice.

Hopefully the OP will post flight logs and provide further flight info like already discussed to see what causes the incident.

 

[MAvic_South_Oz]

One reason I figured it would be a nice feature to have flight profiles with all the settings stored in the profile. Even better would be to have the ability to export the profiles.

You can have your standard profile, one for indoors, one for outdoors with canopy.

Besides using the profile for different flight environments, it can be used to be sure you have all your settings after firmware update.

Absolutely a great idea !
Many flights need loss of connection set to hover (canopy type woods), or low RTH to avoid wind and no obstacles present (ocean), and so on.

It would be so good to have up to say 6 or so options, as that alone could save a lot of pre flight adjustments

 

[WithTheBirds]

I totally agree about salt water immersion and mid to long term ending.
Personally I could never trust such and flying computer ever again in the air after a dip.
Let’s not drag to OPs post off track with further discussion about the drone retriever info.
There are a few things there I was not in total agreement with, but on the whole about equal to anything else with the rinse / isopropyl type of process I’ve seen online.
Ha ha, better than bags of rice.

Hopefully the OP will post flight logs and provide further flight info like already discussed to see what causes the incident.

Yes- let’s not....

To be clear I think the drone-retriever is probably a very good value proposition and almost certainly a good investment so far as it will give you a good chance of recovering a downed sUAV (assuming you can get to it).

 

[Drone-Retriever]

There is a difference between well thought out and best. There are numerous technical inaccuracies of varied potential significance however the main likely issue is that it is over enthusiastic.

The process described for salt water immersion has close to zero prospects of being effective for the longer term (assuming it gets the drone flying in the first instance).

The dunk in a bucket and hope for the best method has a surprising initial success rate. Even with cameras and mobile phones. The fun is short lived however. Sea water isn't a "mild corrosive" (corrosive liquids have Ph significantly higher or lower than that of sea water and are demonstrated to destroy biological tissue on contact) it does however accelerate the corrosion (rusting) process. This is because sea water is, contrary to what is suggested, actually a quite good electrical conductor. It can provide for significant enough unintended current flow within the immersed device to permanently damage electronics, even before the cleaning process is initiated. Mavic batteries are definitely not sealed against moisture ingress and the motors don't contain bushings (they use shielded bearings) with silicon steel laminations for the stator poles. The fact the magnet wire is coated has nothing to do with the fact the coils are wound tightly. I think I stopped reading somewhere around that point.

To: WithTheBirds,
Since you are questioning lets discuss.
Question how many exposed electrical points do you estimate are withing a Mavic NOT counting the memory card port, USB port and battery terminals? Yes you are correct salt water is a better conductor than fresh water. The answer is exposed electrical points should be obvious if you understand what conformal coating is and does.
Also remember the voltage is quite low at 10-15v. Here is a home test. Get a glass of water fill it with water add several tablespoons of sea salt and mix. Get a 12vDC battery rated at 4Ah. This will simulate a typical drone battery. Get a 1/8A fuse (125mA) Get 3 lengths of solid insulated 20-24awg wire and strip the ends about 1/8". Attach them side by side onto a piece of electrical tape or duct tape with a spacing of 1mm. Attache one end to the fuse and the other end to the battery. Take the 3rd wire and attache it to the fuse. Now connect the other end to the battery. (Other Post). Now take the tape with exposed ends and place into glass of salt water. If you are right the fuse will open. If I am right nothing will happen.
Hope this helps

 

[WithTheBirds]

To: WithTheBirds,
Since you are questioning lets discuss.
Question how many exposed electrical points do you estimate are withing a Mavic NOT counting the memory card port, USB port and battery terminals? Yes you are correct salt water is a better conductor than fresh water. The answer is exposed electrical points should be obvious if you understand what conformal coating is and does.
Also remember the voltage is quite low at 10-15v. Here is a home test. Get a glass of water fill it with water add several tablespoons of sea salt and mix. Get a 12vDC battery rated at 4Ah. This will simulate a typical drone battery. Get a 1/8A fuse (125mA) Get 3 lengths of solid insulated 20-24awg wire and strip the ends about 1/8". Attach them side by side onto a piece of electrical tape or duct tape with a spacing of 1mm. Attache one end to the fuse and the other end to the battery. Take the 3rd wire and attache it to the fuse. Now connect the other end to the battery. (Other Post). Now take the tape with exposed ends and place into glass of salt water. If you are right the fuse will open. If I am right nothing will happen.
Hope this helps

Typical sea water is around 1 million times more conductive than pure water, at least 1000 times greater than typical drinking water. More than enough to render sensitive electronic devices inoperable (even if only the board headers are exposed). So we are clear all I am saying is that people should not be overly confident a device will function reliably for any extended period after immersion and rinsing without disassembly. Even with thorough attempts at cleaning residual dissolved solids that remain will continue to attract moisture and potentially cause issues including accelerated corrosion. I suspect the fuse would remain intact with your proposed experiment. You would get a small light bulb connected in circuit to illuminate however if you were to fashion some electrodes from metal foil. I observed one of my kids doing that as a home science experiment.

 

[gvsukids]

app.airdata.com/share/zVxKim

 

[D-Rosin]

i have a question for you guys in here i am reading all of this, so if i was flying out side and all of a sudden my app disconnects from the dji to drone will the drone just stay in place in the sky? until app is connected? or will it RTH?

 

[WithTheBirds]

i have a question for you guys in here i am reading all of this, so if i was flying out side and all of a sudden my app disconnects from the dji to drone will the drone just stay in place in the sky? until app is connected? or will it RTH?

It will depend on what action you have set for signal loss.

 

[MAvic_South_Oz]

And besides what action you have set for signal loss . . . if it can even be selected, eg like at the moment Mavic Mini on IOS, or Spark, at least do not have options apart from forced RTH) . . . some DJI models are different to the way they behave in some of these functions.
Best to thoroughly read your models manual, and in a big open flat area go through options and have a bit of a try of various functions.

To test forced RTH due to signal loss, just get a decent distance away (at least a little more than needed for proper RTH action), hover at a height a little below the set RTH alt, say hover at 15m, RTH set at 20m, then turn off controller.
** Absolutely before this, ensure you have strong GPS, that the home point has been recorded, and to be safer ensure precision landing point has been captured.

You can then try alternative signal loss actions like hover, or land, again ensuring suitable environment around the drone.