(Warning) Avoid this low battery RTH mistake

[dvarapala]

Will we be able to determine the drone didn't just start back up and take off to RTH?

I'm shocked no one has asked the OP to post his flight logs yet.

 

[joejaxvic123]

Yeah, that may help. What also peaks my curiosity is these numerous videos you see where someone is coming home and they don't have enough battery to get back to home point.
They look for a place to ditch it and land safely and go and retrieve the bird with no issues.

 

[kakao]

Yeah, that may help. What also peaks my curiosity is these numerous videos you see where someone is coming home and they don't have enough battery to get back to home point.
They look for a place to ditch it and land safely and go and retrieve the bird with no issues.

Nothing wrong with this I'd say .. if no safer option is available.

 

[Franzinator]

My understanding is that a manual landing with the sticks, and not a ‘swipe right to land’, doesn’t end the flight as far as the drone is concerned. Therefore when it gets to a critically low battery level, it takes off and attempts to come home. I believe this was further compounded by the fact that you shut the controller off, which is interpreted as LOS by the drone, which also causes a RTH.

 

[JMF]

Let me better re-phrase my last comment, if the Mavic was landed AND the props turned off then there is no way it would re-initiate a RTH.

 

[787steve]

While a great recommendation, the FAA disagrees with your interpretation.

Nope. He is right. Not only the FAA, but also for hobbyist flying under Sec 336.

 

[joejaxvic123]

My understanding is that a manual landing with the sticks, and not a ‘swipe right to land’, doesn’t end the flight as far as the drone is concerned. Therefore when it gets to a critically low battery level, it takes off and attempts to come home.

Interesting... very interesting.

 

[787steve]

Fascinating scenario for a noob. I never would have thought of this happening. But I'm not necessarily the type to land my MP away from my position except in an emergency. I'm anxious to see how the tests work out.

 

[joejaxvic123]

Fascinating scenario for a noob. I never would have thought of this happening. But I'm not necessarily the type to land my MP away from my position except in an emergency. I'm anxious to see how the tests work out.

Lol, if I may: You don't necessarily need to be a noob to abort RTH and land elsewhere if your battery is insufficient to make it back to home point. I believe the question here is did the Mavic take off on it's own after an aborted RTH?

 

[ac0j]

I think the only possible explanation was that the Mavic wasnt aware it had "landed". Like I said earier, what f the new landing spot was 2 feet higher than the takeoff point? The mavic would be on the ground, but would "think" it was 2 feet in the air. Of course, this is assuming the motors were never shut down, because if they were, the RTH point would become where it was last landed.

 

[joejaxvic123]

Only tests will confirm, kinda like our bootlegging idea.

I will definitely be doing some RTH tests soon, especially after my mishap.

There's alot going on with these things, one can make a mistake at any moment.

Then there is always a question of the unit making the mistake....

 

[787steve]

Lol, if I may: You don't necessarily need to be a noob to abort RTH and land elsewhere if your battery is insufficient to make it back to home point. I believe the question here is did the Mavic take off on it's own after an aborted RTH?

Agreed. I was saying that I don't have the nerve to do what he did, landing remotely by choice vs. necessity. I would be concerned that an interloper would get to it before I did. But I could see it happening just as you suggested. That's why I am interested in the outcome.

 

[joejaxvic123]

Thanks Steve, no offense, I would not want to land like that either, I'm really interested in this, it's really interesting.

 

[rfc]

I'm shocked no one has asked the OP to post his flight logs yet.

I did (Post #52); The logs will provide the answer many in this thread are conjecturing about. Were the motors running or not?

 

[Yannie]

Guys, I have spent the evening trying to get the flight logs, and also correcting my recollection of some minor aspects of this flight. To very long story short: I know the exact date and time this incident happened. I can confirm that I initially brought the down with 30% battery. The landing site was in fact somewhat lower than the takeoff site, so it would have shown a negative altitude when I was landing it. I have a video of this landing, but it stopped when the controller and/or phone disconnected.

Frustratingly, I have been able to access comprehensive flight logs right up to the point I initially landed it. But I have absolutely nothing from the point after I disconnected my phone. For whatever reason, there aren't flight logs on the drone. Perhaps the logs were overwritten on subsequent flights eg if SD card space was low. I will be able to tell you later if the motor was on when my phone disconnected from the drone, but I'm much more interested in what it's rationale for trying to return to home was, after I disconnected. I've been trying to find evidence of an alert or warning something, but there is nothing. The route just seemed to finish where I landed it. But this is not all that unexpected, as most of the data I've been able to access has come from my phone.

I'm currently going down the DJI assistant 2 -> black box export -> log file pathway, to try to extract any flight information I can from the drone. But I don't properly understand Python yet and so I'm having a lot of trouble decrypting these log files...

Can tell me about a user-friendly way to decrypt DJI black-box log files?

 

[BudWalker]

Guys, I have spent the evening trying to get the flight logs, and also correcting my recollection of some minor aspects of this flight. To very long story short: I know the exact date and time this incident happened. I can confirm that I initially brought the down with 30% battery. The landing site was in fact somewhat lower than the takeoff site, so it would have shown a negative altitude when I was landing it.

Frustratingly, I have been able to access comprehensive flight logs right up to the point I initially landed it. But I have absolutely nothing from the point after I disconnected my phone. For whatever reason, there aren't flight logs on the drone. Perhaps the logs were overwritten on subsequent flights eg if SD card space was low. I will be able to tell you later if the motor was on when my phone disconnected from the drone, but I'm much more interested in what it's rationale for trying to return to home was, after I disconnected. I've been trying to find evidence of an alert or warning something, but there is nothing. The route just seemed to finish where I landed it. But this is not all that unexpected, as most of the data I've been able to access has come from my phone.

I'm currently going down the DJI assistant 2 -> black box export -> log file pathway, to try to extract any flight information I can from the drone. But I don't properly understand Python yet and so I'm having a lot of trouble decrypting these log files...

Can tell me about a user-friendly way to decrypt DJI black-box log files?

You might be able to retrieve the .DAT instead. Look here to see how to do that. If you do manage to get that.DAT then you'll need to Dropbox it and post a link.

 

[phantomi]

Interesting, very interesting. Anybody has try to confirm the theory of the incomplete shutoff of the motors? Has to be in an open field and reset RTH to maybe hover at a low altitude.

 

[Yannie]

Thanks. Pretty sure I've exhausted the dat file pathway though. Will reassess tomorrow.

 

[rfc]

Thanks. Pretty sure I've exhausted the dat file pathway though. Will reassess tomorrow.

You don't need Python to get the .dats. Follow Budwalker's link. It works.

 

[BudWalker]

You don't need Python to get the .dats. Follow Budwalker's link. It works.

Maybe not. Looks like @Yannie ran into the problem that a lot of pilots (including me) have run into. For FW > 01.03.0900 the desired flight doesn't show up when using the DJI Assistant.