Lost signal in flight

[Vangaurd]

Mavic Pro lost connection to RC mid flight in high winds and I was hoping someone could tell me what happens to the bird in this scenario. I had home recorded before take off and I waited at home point beyond the birds battery life. What does the bird do in these situations? Hover until battery dies? Fly away to places unknown? Continue on path it was on prior to signal loss?
Thanks

 

[Meta4]

Mavic Pro lost connection to RC mid flight in high winds and I was hoping someone could tell me what happens to the bird in this scenario. I had home recorded before take off and I waited at home point beyond the birds battery life. What does the bird do in these situations? Hover until battery dies? Fly away to places unknown? Continue on path it was on prior to signal loss?

This is something basic that you should understand before flying.
It's explained on page 13 of the manual.

Failsafe RTH

If the Home Point was successfully recorded and the compass is functioning normally, and the Loss of Signal Action is set to RTH, Failsafe RTH will be automatically activated if the remote controller signal is lost for a specified amount of time (3 seconds when using the remote controller and 20 seconds when using Wi-Fi). ​

Return-to-Home can be cancelled by the pilot, allowing them to regain control when the remote controller signal connection is re-established.​

Since your drone didn't return, it's likely that there's more to this incident than a simple loss of signal.
To find out what happened to your drone, and why it didn't come back, you'll need to post your recorded flight data.

There are a couple of options ...

1. 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 on the flight data.
Come back and post a link to the report it provides and someone might be able to analyse it and give you an understanding of the cause of the incident.
or
2. Just post the .txt file here
or
3. If you use Airdata, you can view the flight data on Airdata and post a link for the Airdata report

 

[msinger]

What does the bird do in these situations? Hover until battery dies? Fly away to places unknown? Continue on path it was on prior to signal loss?

Depending on the wind, whether or not it was using GPS, remaining battery power, and your settings in DJI GO 4, it would have most likely done one of the following:

- Return to the home point and land
- Attempt to return to the home point and land at the point where the battery is too low to continue flying
- Crash into an obstacle while attempting to return to the home point
- Hover in place and land when the battery is too low to continue hovering
- Land at its current location
- Drift away with the wind and land at the point where the battery is too low to continue drifting

It will be easier to determine which of these are possibilities if you share your flight log.

 

[Vangaurd]

This is something basic that you should understand before flying.
It's explained on page 13 of the manual.

Failsafe RTH

If the Home Point was successfully recorded and the compass is functioning normally, and the Loss of Signal Action is set to RTH, Failsafe RTH will be automatically activated if the remote controller signal is lost for a specified amount of time (3 seconds when using the remote controller and 20 seconds when using Wi-Fi). ​

Return-to-Home can be cancelled by the pilot, allowing them to regain control when the remote controller signal connection is re-established.​

Since your drone didn't return, it's likely that there's more to this incident than a simple loss of signal.
To find out what happened to your drone, and why it didn't come back, you'll need to post your recorded flight data.

There are a couple of options ...

1. 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 on the flight data.
Come back and post a link to the report it provides and someone might be able to analyse it and give you an understanding of the cause of the incident.
or
2. Just post the .txt file here
or
3. If you use Airdata, you can view the flight data on Airdata and post a link for the Airdata report

Well said. Thank you

 

[RodPad]

RTH is a Fail Safe
But as we learn it fails if you don't understand it. (Been There)

I'm a guy that bugs members to upload there flight log, we all learn from these.

@Meta4
Gave a you quick link.
Here is my nudge?

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

Rod ..

 

[Meta4]

Mavic Pro lost connection to RC mid flight in high winds and I was hoping someone could tell me what happens to the bird in this scenario.

As well as finding the reason, your flight data might help find where your drone ended up ..... but you need to post it for the data whisperers to be able to help.

 

[Vangaurd]

Meta4.....the 1st sentence of your in initial reply pretty much sums it up. I understand how it should work but it DID NOT work the way page 13 of the manual states it should and was reason for my query. I wonder how often someone sees what happens when a question is posed and would rather not know than to be unfairly scolded on this public forum. I have reviewed the data and i have replayed the flight on Airdata UAV. I have ZERO interest in becoming your opportunity to make an uninformed and rude comment so now nobody will know what happened and that learning opportunity for all ended with your need to tell me what i already know. Again, thank you for the info you provided....it sent me in the right direction so for that.....thank you.

 

[Vangaurd]

RTH is a Fail Safe
But as we learn it fails if you don't understand it. (Been There)

I'm a guy that bugs members to upload there flight log, we all learn from these.

@Meta4
Gave a you quick link.
Here is my nudge?

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

Rod ..

Rod this is gold! I had no idea that it could get that involved in the data mining. Love to share what i have learned...and as a pilot i am rather ashamed that i choose to fly that day.

 

[Meta4]

Meta4.....the 1st sentence of your in initial reply pretty much sums it up. I understand how it should work

Then why ask such a basic question?
Your exact words were:

I was hoping someone could tell me what happens to the bird in this scenario.​

Excuse me for answering the question you asked.

The post that followed mine also understood your post the same way I did (because that's the only way anyone could read it).

but it DID NOT work the way page 13 of the manual states it should and was reason for my query.

And I anticipated that and answered before you asked:

Since your drone didn't return, it's likely that there's more to this incident than a simple loss of signal.​

To find out what happened to your drone and why it didn't come back, you'll need to post your recorded flight data.​

I have ZERO interest in becoming your opportunity to make an uninformed and rude comment so now nobody will know what happened and that learning opportunity for all ended with your need to tell me what i already know. Again, thank you for the info you provided....it sent me in the right direction so for that.....thank you.

I have zero interest in making rude or uninformed comments (and I didn't).
But despite your rude and uninformed comments I have an interest in your incident and helping you, if you can get off your high horse.

 

[RodPad]

Meta4 is one of the best in helping people figuring out most likely what actually happened, may be able to point you on where it went.

I watch all of these threads, we all learn from the facts.

Basically I'm going to stay off this thread until it changes back positive direction.

Send me a PM if you got something to tell me personally.

Rod ..

 

[Vangaurd]

Here is the Data

 

[RodPad]

Thanks, for not bailing out on this
The .dat files are beyond my capabilities , about 10 members here will tell you if that's what they need.

Rod ..

 

[Vangaurd]

DJI Flight Log Viewer - PhantomHelp.com

 

[slup]

DJI Flight Log Viewer - PhantomHelp.com

My belief is that your drone didn't return as a result of a battery failure... the disconnect you got there in the end was most probably where the drone shut off.

This battery was really, really bad (from Feb 2017)... the battery management system said 97% when the flight started, but as soon as you took off & the amp draw increased all cells sagged severely... cell 2 suffered the most, dropping below 3.0V (lowest level before permanent damage occurs for a LiPo battery) already 35sec into the flight. Have never ever seen such a large cell deviation as in this flight... nearly a full volt.

All then became just worse when you switched to Sport mode... there all cells dropped & it was just a matter of time until the total voltage should be so low that it no longer could keep the motors going.

It's really a mystery why a forced critical low voltage landing wasn't initiated... was this drone modded in some way?

Here the important data... pink+green background to the left is motor start & take off, then blue as in normal mode & ending with pink which is Sport mode. The meaning of the graphs is in the legend beneath the chart with values from where I've placed the chart marker at 8,6sec into the flight.

(Click on the chart to make it larger)



The log also show lots of "Compass error" & in the end some "Motors Blocked"... maybe unrelated.

 

[RodPad]

WOW!, Thanks for your time!

I wrote a POS program for our retail store in 1989. Modified it until 2021.
I just cannot get to this level.

You got @Meta4 and @BudWalker with you on this one!!

Rod ..

 

[Vangaurd]

This is great info and i appreciate it very much. I have contacted property owner and have permision to look for and possibly find/retrieve. I might even take my M2 and map area and see if i can identify its spot 1st before i go hiking.

Thank you slup for the research and intel....

 

[Vangaurd]

WOW!, Thanks for your time!

I wrote a POS program for our retail store in 1989. Modified it until 2021.
I just cannot get to this level.

You got @Meta4 and @BudWalker with you on this one!!

Rod ..

My belief is that your drone didn't return as a result of a battery failure... the disconnect you got there in the end was most probably where the drone shut off.

This battery was really, really bad (from Feb 2017)... the battery management system said 97% when the flight started, but as soon as you took off & the amp draw increased all cells sagged severely... cell 2 suffered the most, dropping below 3.0V (lowest level before permanent damage occurs for a LiPo battery) already 35sec into the flight. Have never ever seen such a large cell deviation as in this flight... nearly a full volt.

All then became just worse when you switched to Sport mode... there all cells dropped & it was just a matter of time until the total voltage should be so low that it no longer could keep the motors going.

It's really a mystery why a forced critical low voltage landing wasn't initiated... was this drone modded in some way?

Here the important data... pink+green background to the left is motor start & take off, then blue as in normal mode & ending with pink which is Sport mode. The meaning of the graphs is in the legend beneath the chart with values from where I've placed the chart marker at 8,6sec into the flight.

(Click on the chart to make it larger)
View attachment 172282


The log also show lots of "Compass error" & in the end some "Motors Blocked"... maybe unrelated.

Yes....modded and i did see battery warning and also has a slight swell so very poor decision making on the PIC part but was a calculated risk with remote location and mission.

 

[slup]

... to look for and possibly find/retrieve.

This is the last recorded position in the log, most probably here the motors shut off & the drone started to fall & deaccelerate from the 20mph it had... so a good GPS position to start out the search with.

The drone were tilted in a compass direction of 141, 63 degrees, so that can be the direction past the last known position you can search in with a hand compass. The wind were coming in from the right side of the drone (approx. SW)... so look to the left of the theoretical path continuation.

 

[Vangaurd]

This is the last recorded position in the log, most probably here the motors shut off & the drone started to fall & deaccelerate from the 20mph it had... so a good GPS position to start out the search with.

The drone were tilted in a compass direction of 141, 63 degrees, so that can be the direction past the last known position you can search in with a hand compass. The wind were coming in from the right side of the drone (approx. SW)... so look to the left of the theoretical path continuation.

View attachment 172308

GOLD! Thank you

 

[Vangaurd]

Have not found after 3 walks of the area and a review of a detailed mapping I took. One more attempt before i give up.