Near disaster Mavic pro

[windless]

At the beach yesterday and forgot my phone. My son was about 40m offshore surfing so I thought I would get some shots just using the controller unit as all was well within sight.
Unfortunately , it must have switched to beginner mode and then reset my son as the home point while I hovered over him.
This resulted in it trying to descend into the ocean when I pressed the RTH button. Cancelling this and attempting to fly back to shore I discovered that the shore line was about 5m beyond the 30 maximin flight radius.
This resulted in some very dexterous moves by my son in the surf zone trying to catch the drone while sitting on his board.
Fortunately it ended well, but the lack of option on the controller did give me some pause.

 

[MAvic_South_Oz]

That's something I haven't seen or heard of before.
What would be really interesting for you and others, might be to post the flight TXT log so it can be assessed for the reason this happened.

Always good to know what can occur when flying.

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

Just follow the instructions above and post a link to the report.
The analytical people can get what they need there, or maybe ask for the DAT too if needed.

It's lucky your son was there to assist, and very glad your Mavic didn't go swimming.

 

[Meta4]

That's something I haven't seen or heard of before.
What would be really interesting for you and others, might be to post the flight TXT log so it can be assessed for the reason this happened.

Without the phone there's no app and no recorded flight data.

 

[Meta4]

Unfortunately , it must have switched to beginner mode and then reset my son as the home point while I hovered over him.

Resetting the home point can only happen if you do it in the app.
There's no way to do that with just the controller.

 

[Keule]

Unfortunately , it must have switched to beginner mode

it's a normal behavior while no phone/tablet is connected:

 

[MAvic_South_Oz]

Without the phone there's no app and no recorded flight data.

Oh dang yeah, would DAT from aircraft be able to help with flight analysis in a similar way ?
Only if M1P or MPP, as per thread title, they can be retrieved.

Mavic Flight Log Retrieval and Analysis Guide

With the introduction of the Mavic Mini there has been a noticeable uptick in the number of posts requesting help with lost or crashed aircraft. While there is plenty of help and advice available on this forum, and detailed guidance and options on several other websites, I thought that perhaps a...

mavicpilots.com

Aircraft DAT files

These are only readable from the Mavic Pro and Mavic Pro Platinum (plus Phantom 3, Inspire 1, Phantom 4, Phantom 4 Pro, Inspire 2, Inspire 2 Pro, Matrice 100, Matrice 200, Matrice 600, and Spark). A guide to retrieving them from the aircraft can be found on @BudWalker's DatCon website. They are much larger files than the mobile device files, and generally too large to post directly to this forum. The best solution is to upload them to Dropbox or similar and then post a link.

 

[PhantomFandom]

At the beach yesterday and forgot my phone. My son was about 40m offshore surfing so I thought I would get some shots just using the controller unit as all was well within sight.
Unfortunately , it must have switched to beginner mode and then reset my son as the home point while I hovered over him.
This resulted in it trying to descend into the ocean when I pressed the RTH button. Cancelling this and attempting to fly back to shore I discovered that the shore line was about 5m beyond the 30 maximin flight radius.
This resulted in some very dexterous moves by my son in the surf zone trying to catch the drone while sitting on his board.
Fortunately it ended well, but the lack of option on the controller did give me some pause.

Of course there is no way of telling without the logs but I don't think that is what happened. It won't randomly reset the home point during flight. What I think may have happened is that you took off before the home point was set at all. Then by the time the MP was able to lock on to GPS and set a home point, you were already over the ocean. Without a device and app attached, it did what it is programmed to do and set a maximum flight radius from the home point.

 

[sar104]

Oh dang yeah, would DAT from aircraft be able to help with flight analysis in a similar way ?
Only if M1P or MPP, as per thread title, they can be retrieved.

Mavic Flight Log Retrieval and Analysis Guide

With the introduction of the Mavic Mini there has been a noticeable uptick in the number of posts requesting help with lost or crashed aircraft. While there is plenty of help and advice available on this forum, and detailed guidance and options on several other websites, I thought that perhaps a...

mavicpilots.com

Aircraft DAT files

These are only readable from the Mavic Pro and Mavic Pro Platinum (plus Phantom 3, Inspire 1, Phantom 4, Phantom 4 Pro, Inspire 2, Inspire 2 Pro, Matrice 100, Matrice 200, Matrice 600, and Spark). A guide to retrieving them from the aircraft can be found on @BudWalker's DatCon website. They are much larger files than the mobile device files, and generally too large to post directly to this forum. The best solution is to upload them to Dropbox or similar and then post a link.

The aircraft DAT file will be readable, and should answer the questions. My suspicion is that the aircraft took off without a GPS lock, and that the home point was not set until it was already out over the water.

 

[MAvic_South_Oz]

The aircraft DAT file will be readable, and should answer the questions. My suspicion is that the aircraft took off without a GPS lock, and that the home point was not set until it was already out over the water.

Excellent, wasn't totally sure what info that gave you.
So if @windless wants to know for sure, they can go through the process at post #6, should be able to get the dat off his aircraft . . . as long as it is an M1P or MPP, which is hopefully the case.

 

[GerdS]

This was fully normal behaviour!

First I guess you took off before the home point was set and flew in direction to your son. At some point GPS was stable enough and the home point was set.
It is well known that the Mavic is in a beginner-like mode by default, until the GO4 app will unlock it. And as you didn't have your phone connected, there was no unlock, so it was limited to about 40m distance.

The same happens e.g. if you are trying to fly the Mavic just with the DJI Goggles and no phone, as the DJI Goggles can't unlock the Mavic, too.

Finally, if the home point was set while your Mavic was already more than 40m away from you, it was no longer able to return to your place.

 

[MAvic_South_Oz]

And as you didn't have your phone connected, there was no unlock, so it was limited to about 40m distance.

The same happens e.g. if you are trying to fly the Mavic just with the DJI Goggles and no phone, as the DJI Goggles can't unlock the Mavic, too.

I've flown my M1P just a few times in several years only using the controller, didn't notice any 40m restriction, but I'll try it maybe next time to confirm.
I thought that was the case for flying WITHOUT the controller, when using the phone with wifi mode ??

I have read posts here before where people have flown BVLOS with the controller, no device, and been able to use telemetry to fly back, but maybe that was more in the case of a video transmission outage.

It makes sense to have limitations when flying with controller and no phone, or when flying with phone only using wifi only.
Both aren't really a good idea in my mind for 99.9% of flying most of us would do.
Unless you forgot the controller or device, there's just not much point.

The goggles part . . . I fly my M1P with the ipad normally running too, so I can't be sure about that limitation you mention.
But I do fly the Spark well past 40m, up to perhaps 500m or so normally, and that only has the ability to fly using the goggles with cable connection from the controller.

 

[slup]

...The goggles part . . .
But I do fly the Spark well past 40m, up to perhaps 500m or so normally, and that only has the ability to fly using the goggles with cable connection from the controller.

If you start up with your screen device with GO4 in the RC first ... then disconnect it & plug in the goggles no height or distance restrictions will be activated. If you do it like this then perhaps that's why you haven't noticed anything.

 

[MAvic_South_Oz]

If you start up with your screen device with GO4 in the RC first ... then disconnect it & plug in the goggles no height or distance restrictions will be activated. If you do it like this then perhaps that's why you haven't noticed anything.

I don't usually connect the phone or mini 4 when using the Spark and goggles.
I'll double check when I eventually get out for another fly.

 

[windless]

Thanks for all your comments. I will try try and upload the flight data as suggested.
When it first took off it did indicate ALTT mode and then switched to GPS mode while hovering (I think). As it was close I was not too concerned. I was in a pretty remote area of the WA coast.
Cheers

 

[windless]

DJI_ASSISTANT_EXPORT_FILE_2020-04-13_11-00-02.DAT

Shared with Dropbox

www.dropbox.com

 

[windless]

Try again

Transfer - Dropbox

Dropbox is a free service that lets you bring your photos, docs, and videos anywhere and share them easily. Never email yourself a file again!

www.dropbox.com

 

[MAvic_South_Oz]

Cool, hopefully the right info needed, will be interesting to see what people can find in this.
The DAT info requires some special software to read, and knowledge of the data.
Someone should be alone for a look and post up how it all looks.
It'll possibly be what has been proposed in some replies re home point and distance limitations, but good to confirm.

 

[slup]

DJI_ASSISTANT_EXPORT_FILE_2020-04-13_11-00-02.DAT

Shared with Dropbox

www.dropbox.com

This one doesn't seem to be the right one ... this just contain a start attempt on the beach which is aborted before take off, then a power down. The log just covers roughly 40sec after "Assisted takeoff" attempt ...