Drone down

[CyrusBlack]

Up in Vermont this weekend shooting the foliage. Everything was going well and I was navigating upstream on a nice river. Lost transmission and the drone decided to take a left and start on its own adventure. It smashed into a rock ledge and my video transmission was done. I checked the last know footage transmitted and matched it up to the area on the river. Climbed dow the ledge 30-40 feet (very steep and dangerous) while my buddy was on top. Looked everywhere below while he looked in the crevices above. I finally accepted the possibility that it tumbled down into the river. I looked for a good 10 min everywhere in the vicinity and no less than 1 min before I was about to give up I saw it still blinking under water. Got to it and went down almost to my shoulder and grabbed it. Pulled the battery to shut it down. Battery had 3 solid green lights that wouldn't go off so I just let it die. I dried it off as best as I could and blew it out with air and then dropped the drone into a huge bag of rice for 24 hours. I put a fresh battery in it today and it turns on but the 2 front lights are solid Red and the tail light is solid Red. That's all I got for you guys. Thank God I did take out the DJI Refresh plan when I bought it. Gonna call them tomorrow when they open.

 

[John MacAulay]

Wow, what an ordeal. If you can post your logs it would be interesting to determin what happened.
Thank goodness you had refresh and were able to retrieve your bird. Would be nice to know why it veered to the left.

 

[CyrusBlack]

This is the last flight record in my log so I am assuming that this is it? I will leave this to the Guru's to look at and report back the reason why I'm a dumbass

 

[Meta4]

This is the last flight record in my log so I am assuming that this is it? I will leave this to the Guru's to look at and report back the reason why I'm a dumbass

You never had GPS for the whole flight.
No home point recorded and your drone was in atti mode the whole time.
Without GPS, the drone had no horizontal position holding ability, no brakes and would drift on any breeze.
It's unlikely that the drone "decided to take a left and start on its own adventure ".

 

[Meta4]

You could be more respectful to people who are trying to help you understand what happened!

I believe he was but the wording may have been unclear.

I should have added a link to the flight data to show what was happening during the flight:

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

 

[Gryphon962]

You never had GPS for the whole flight.
No home point recorded and your drone was in atti mode the whole time.
Without GPS, the drone had no horizontal position holding ability, no brakes and would drift on any breeze.
It's unlikely that the drone "decided to take a left and start on its own adventure ".

I see the log showing GPS_Atti mode for most of the flight, with Atti mode just for a few seconds at the end. So I offer a subtle variation on your analysis; he was in GPS Mode, but with just 5-8 sats the nav solution would be poor at best. Then, at a late stage of the flight the FC decided to drop to ATTI mode, and off it went. However, I dont know why it decided to go into ATTI mode when it did.

 

[Meta4]

I see the log showing GPS_Atti mode for most of the flight, with Atti mode just for a few seconds at the end. So I offer a subtle variation on your analysis; he was in GPS Mode, but with just 5-8 sats the nav solution would be poor at best. Then, at a late stage of the flight the FC decided to drop to ATTI mode, and off it went. However, I dont know why it decided to go into ATTI mode when it did.

Look a little deeper and you see that although it says GPS Mode, there is no distance from home shown.
Look at the actual numbers by opening the CSV file, you'll see that there was never any GPS data recorded, either for the home point or the drone's location.
You'll also see that GPS Level never increases past zero for the whole flight and the max number of satellites was 8 (and less for most of the time).
It's likely that the flight was conducted where terrain blocked much of the drone's skyview and satellite reception..
The drone was actually flying in atti mode despite the app reporting P-GPS Mode.

 

[Gryphon962]

Look a little deeper and you see that although it says GPS Mode, there is no distance from home shown.
Look at the actual numbers by opening the CSV file, you'll see that there was never any GPS data recorded, either for the home point or the drone's location.
You'll also see that GPS Level never increases past zero for the whole flight and the max number of satellites was 8 (and less for most of the time).
It's likely that the flight was conducted where terrain blocked much of the drone's skyview and satellite reception..
The drone was actually flying in atti mode despite the app reporting P-GPS Mode.

I concur. Interesting that the app can report P-GPS Mode despite recording no GPS data in use and having navhealth = 0.

@CyrusBlack - I hope you feel less of (removed) now..

 

[sar104]

I concur. Interesting that the app can report P-GPS Mode despite recording no GPS data in use and having navhealth = 0.

@CyrusBlack - I hope you feel less of (removed) now..

It's more complicated than that. P-GPS mode is "flycState = 6", and actually just indicates that the FC is in positioning mode. That could be GPS, or it could be vision positioning, and so you have to look deeper into the log data to see what is happening. In this case the FC never had a navHealth value high enough to use GPS, and it was using vision positioning until 374 seconds, when it dropped out for a couple of seconds, and then 391 seconds when it was lost. At that point the satellite count was varying between 4 and 6, with a navHealth of zero, and so it dropped into ATTI mode..



Note also that the FC almost certainly did have a GPS position solution - it just didn't trust it with so few satellites.

@CyrusBlack - if you want to retrieve that DAT file (FLY031.DAT) then it will likely have a reasonably accurate flight track.

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

 

[The RAPier]

There was a post last week about drying electronics in a rice bag. It was informative and concluded that a rice bag will do more harm than good as it does not stop corrosion damage. Hopefully DJI refresh can save yer little buddy.

 

[CyrusBlack]

It's likely that the flight was conducted where terrain blocked much of the drone's skyview and satellite reception..
The drone was actually flying in atti mode despite the app reporting P-GPS Mode.

@ Meta4 - You are correct - I was traversing up a medium size river that had many cascading falls. I was standing 40 feet +/- above the flight path flying away from myself. I am chalking this up to seeing a really beautiful opportunity and making a bad decision to pursue it.

@sar104 - thanks for the technical stuff.

@RAPier - Just got off the chat with DJI and the 1st of 2 DJI Care Refresh claims was seamless. I told them the complete truth, as embarrassing as it is, and they are replacing it without any issues.

This is for everyone on the Forum to hopefully give a better perspective on what happened.

 

[Deleted member 94047]

@ Meta4 - You are correct - I was traversing up a medium size river that had many cascading falls. I was standing 40 feet +/- above the flight path flying away from myself. I am chalking this up to seeing a really beautiful opportunity and making a bad decision to pursue it.

@sar104 - thanks for the technical stuff.

@RAPier - Just got off the chat with DJI and the 1st of 2 DJI Care Refresh claims was seamless. I told them the complete truth, as embarrassing as it is, and they are replacing it without any issues.

This is for everyone on the Forum to hopefully give a better perspective on what happened.

Glad you got it sorted out with DJI, that would have hurt a lot more if you didn't have Refresh. Also, beautiful shots going up the river. But I kept saying "you are too low, you are way too low!" as I was watching that. You are much braver than I am

 

[Neil Reid]

Somewhat off topic, but you guru's who can analyze flight data like that have my sincere respect. We're fortunate to have access to you. Many thanks indeed.

 

[CyrusBlack]

I know it looks like I am flying way to low in the video but for the first part, where have line of sight, it was actually higher than it appears in the video. Should have stopped at the top of that last rock and just revealed around the corner and then returned to home instead of continuing on.

 

[kwilliams6045]

It's more complicated than that. P-GPS mode is "flycState = 6", and actually just indicates that the FC is in positioning mode. That could be GPS, or it could be vision positioning, and so you have to look deeper into the log data to see what is happening. In this case the FC never had a navHealth value high enough to use GPS, and it was using vision positioning until 374 seconds, when it dropped out for a couple of seconds, and then 391 seconds when it was lost. At that point the satellite count was varying between 4 and 6, with a navHealth of zero, and so it dropped into ATTI mode..

View attachment 83109

Note also that the FC almost certainly did have a GPS position solution - it just didn't trust it with so few satellites.

@CyrusBlack - if you want to retrieve that DAT file (FLY031.DAT) then it will likely have a reasonably accurate flight track.

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

How in the world do y’all learn all this stuff. I understand what you’re saying but to read all that from the logs is a skill for sure!!! Good job fellas!!!!

 

[MBurris]

Up in Vermont this weekend shooting the foliage. Everything was going well and I was navigating upstream on a nice river. Lost transmission and the drone decided to take a left and start on its own adventure. It smashed into a rock ledge and my video transmission was done. I checked the last know footage transmitted and matched it up to the area on the river. Climbed dow the ledge 30-40 feet (very steep and dangerous) while my buddy was on top. Looked everywhere below while he looked in the crevices above. I finally accepted the possibility that it tumbled down into the river. I looked for a good 10 min everywhere in the vicinity and no less than 1 min before I was about to give up I saw it still blinking under water. Got to it and went down almost to my shoulder and grabbed it. Pulled the battery to shut it down. Battery had 3 solid green lights that wouldn't go off so I just let it die. I dried it off as best as I could and blew it out with air and then dropped the drone into a huge bag of rice for 24 hours. I put a fresh battery in it today and it turns on but the 2 front lights are solid Red and the tail light is solid Red. That's all I got for you guys. Thank God I did take out the DJI Refresh plan when I bought it. Gonna call them tomorrow when they open.

I have the opposite story. I got a new Mavic P2 direct from DJI and tried it out immediately. I got a processor overheating issue upon start. I kept trying; eventually I got it started and it flew nicely - for a day. Made a few short flights just for calibration and to gain more familiarity with the Go app. A few days later I made a longer flt - all ok. Next try the overheating error recurred and didn’t correct itself. Sent it to DJI for warranty or repair. No joy. They said water damage. The bird was no where near water although I did make a flt over a lake at 11’. Trying to convince them to satisfy me. Since I needed the drone quickly, I used one of my Refresh units for replacement. Shouldn’t I get the Refresh credit back and the $140 fee? Or should I just chalk it up to the saint of lost causes?

 

[sar104]

How in the world do y’all learn all this stuff. I understand what you’re saying but to read all that from the logs is a skill for sure!!! Good job fellas!!!!

Mostly lot's of exploration of log files, and many conversations with @BudWalker.

 

[MBurris]

This is the last flight record in my log so I am assuming that this is it? I will leave this to the Guru's to look at and report back the reason why I'm a dumbass

I tried spell checking it and my computer exploded.

 

[kwilliams6045]

I have the opposite story. I got a new Mavic P2 direct from DJI and tried it out immediately. I got a processor overheating issue upon start. I kept trying; eventually I got it started and it flew nicely - for a day. Made a few short flights just for calibration and to gain more familiarity with the Go app. A few days later I made a longer flt - all ok. Next try the overheating error recurred and didn’t correct itself. Sent it to DJI for warranty or repair. No joy. They said water damage. The bird was no where near water although I did make a flt over a lake at 11’. Trying to convince them to satisfy me. Since I needed the drone quickly, I used one of my Refresh units for replacement. Shouldn’t I get the Refresh credit back and the $140 fee? Or should I just chalk it up to the saint of lost causes?

I’d be ticked off... they should’ve been able to back it up with photos or something rather than just concluding it had water damage!!!

 

[MBurris]

I’d be ticked off... they should’ve been able to back it up with photos or something rather than just concluding it had water damage!!!

They did. The pic showed some odd brown crud on one of the arms that wasn’t there when I sent it back to DJI. They provided a quote, without any detail, of over $1,000 to repair. I did get a lot of sympathetic responses. I’m upset because I know it was essentially a disaster in the making the day I got it and either DJI thinks I’m lying. Moral of the story; if there’s a message on the Go app, send it back immediately regardless of whether it subsequently flies.