Battery 15% - does forced landing use RTH elevation setting ?

[swb_mct]

I forgot that it takes about 5 minutes to descend 1630 feet (In the wilderness 50 miles from any type of airport) and the only place to land at my location is under a tree canopy or in the lake. So I spent about 30 seconds under the trees while landing at around 15% battery. I was sweating the possibility of it bolting up into the trees as I was landing under the trees. Would that happen and what could I do about it at that moment ?

( a secondary point that may be raised here . . is it illegal to shoot pictures at 1600 feet in the wilderness ? Is the 400 foot guideline just a guideline )

 

[msinger]

The forced landing occurs when the battery reaches the critically low level. That could occur at 10%, 15%, 17%, 20%, etc. There is no set percentage since the calculation is largely (or totally?) based on the aircraft's current altitude. When the auto landing is trigger, the aircraft will descend and land at its current location.

 

[sar104]

Forced landing does not involve climbing to the RTH altitude - that would be somewhat counterproductive.

As for your second question, if you are in the US and you mean actual designated wilderness then it is illegal to fly there at all. If you just mean out in the backcountry and you were flying recreationally then the 400 ft limit is just FAA guidance.

 

[sar104]

The forced landing occurs when the battery reaches the critically low level. That could occur at 10%, 15%, 17%, 20%, etc. There is no set percentage since the calculation is largely (or totally?) based on the aircraft's current altitude. When the auto landing is trigger, the aircraft will descend and land at its current location.

There are two possible triggers. Forced landing occurs at the set critical low battery level (default 10% unless changed), while the smart battery autoland occurs when the the smart power autoland level (calculated by altitude) falls below the battery %.

 

[msinger]

Forced landing occurs at the set critical low battery level (default 10% unless changed)

There is no way to adjust the critically low battery percentage. It's always auto calculated (and recalculated constantly in real-time). The setting you're referring to only adjusts when a warning message appears in DJI GO.

the smart battery autoland occurs when the the smart power autoland level (calculated by altitude) falls below the battery %.

I've never heard of a smart power autoland feature. Are you referring to the "Smart Return-to-Home" setting in DJI GO?

 

[sar104]

There is no way to adjust the critically low battery percentage. It's always auto calculated (and recalculated constantly in real-time). The setting you're referring to only adjusts when a warning message appears in DJI GO.


I've never heard of a smart power autoland feature. Are you referring to the "Smart Return-to-Home" setting in DJI GO?

The "critically low battery warning" (SMART_BATTERY.seriousLowWarning) is the second adjustable level in the Go app. The aircraft will autoland at that level unless "SMART_BATTERY.landBattery", which is calculated based on descent time, is higher than the set level (which it often is) and "SMART_BATTERY.seriousLowWarningLanding" is set to "True".

I haven't dug into the question of what sets that to "True" - it seems to be independent of the smart RTH setting, and it may be a non-user-configurable default. I don't ever recall seeing it set to "False".

Here is an example of those parameters leading to autoland:




.

 

[Cuervo]

You may fly at the edge of a designated Wilderness boundary and take photos from there, it's illegal to fly over designated Wilderness. This same rule applies to the National Parks. You may want to consider using the term 'backcountry' if you're just in the mountains or the forests, it may keep people from becoming upset with you, or worse yet tracking you. If you're flying in designated Wilderness areas then please cease doing so.
As far as landing the drone goes, you may want to consider finding a launch site with a clear area overhead, it doesn't take much.
Thanks in advance for your consideration.

 

[sar104]

You may fly at the edge of a designated Wilderness boundary and take photos from there, it's illegal to fly over designated Wilderness. This same rule applies to the National Parks. You may want to consider using the term 'backcountry' if you're just in the mountains or the forests, it may keep people from becoming upset with you, or worse yet tracking you. If you're flying in designated Wilderness areas then please cease doing so.
As far as landing the drone goes, you may want to consider finding a launch site with a clear area overhead, it doesn't take much.
Thanks in advance for your consideration.

Actually it is legal to fly over NPS land or designated wilderness - you just can't take off or land from those areas.

 

[msinger]

The "critically low battery warning" (SMART_BATTERY.seriousLowWarning) is the second adjustable level in the Go app. The aircraft will autoland at that level unless "SMART_BATTERY.landBattery", which is calculated based on descent time, is higher than the set level (which it often is) and "SMART_BATTERY.seriousLowWarningLanding" is set to "True".

Got a flight log showing the aircraft landing due to the battery reaching the critically low battery warning level? I've never seen such a thing.

 

[Cuervo]

Actually it is legal to fly over NPS land or designated wilderness - you just can't take off or land from those areas.

Thanks for this clarification.

 

[sar104]

Got a flight log showing the aircraft landing due to the battery reaching the critically low battery warning level? I've never seen such a thing.

Good question. Not that I could find easily, so that needed an experiment. The results are somewhat interesting. I set the low warning level to 30% and the critically low warning level to 20%, disabled smart RTH and then hovered the aircraft.



The smart battery RTH level defaulted to 15%. It could obviously go higher with distance, but the aircraft was at the home point. The smart battery land level remained at 10%. That could obviously go higher with altitude too, but the aircraft was only 2 m above ground. What seems strange is that it was below the critical low battery level (20%) even though "SMART_BATTERY.seriousLowWarning" was set to 20% and "SMART_BATTERY.seriousLowWarningLanding" was set to "True".

As the battery depletes it issues the expected warnings at 30% and 20% but, contrary to the manual (p. 15) that states that it will autoland at the critical low battery warning level, it did not do so. The smart battery status changed to critical low battery, but not to autoland. It did not switch to autoland until the battery % dropped to the smart battery land level (10%).

Conclusion: the smart battery functions appear to have superseded the user-defined battery levels, and those are now simply warnings, even though the manual continues to state otherwise and the logged data imply that it should land at the critically low warning level.

 

[ac0j]

Actually it is legal to fly over NPS land or designated wilderness - you just can't take off or land from those areas.

Thanks for this clarification.

think it is clear that flying in NPS is frowned upon. The fact that you can "skirt" the restriction and take off outside and fly in is an irresponsible act. Its not the take off and landing that the restrictions are in place for. So expect a confrontation if you do so, take your ticket, and see if you can beat it in court. If you have that time to waste. Better to go to the park gift shop and buy a couple postcards of photos you like. its not like your pictures will be any better quality anyway.
When you register with the FAA one of the few things you see is them asking you to not fly around populations and not over 400'. its not law, but in a sense you are agreeing to those restrictions by completing the registration.
With NFZ's, and Altitude restrictions, You are politely asked NOT to do it.
If you are the type of person that farts in elevators, or doesnt use deodorant, I wouldnt expect compliance from you.

 

[sar104]

think it is clear that flying in NPS is frowned upon. The fact that you can "skirt" the restriction and take off outside and fly in is an irresponsible act. Its not the take off and landing that the restrictions are in place for. So expect a confrontation if you do so, take your ticket, and see if you can beat it in court. If you have that time to waste. Better to go to the park gift shop and buy a couple postcards of photos you like. its not like your pictures will be any better quality anyway.
When you register with the FAA one of the few things you see is them asking you to not fly around populations and not over 400'. its not law, but in a sense you are agreeing to those restrictions by completing the registration.
With NFZ's, and Altitude restrictions, You are politely asked NOT to do it.
If you are the type of person that farts in elevators, or doesnt use deodorant, I wouldnt expect compliance from you.

I'm not sure what you mean by "frowned upon". The NPS has stated that it is legal.

 

[ac0j]

I'm not sure what you mean by "frowned upon". The NPS has stated that it is legal.

The NPS has BANNED drones within their boundaries. Thats a pretty clear statement on what they think about drones.
They have only admitted that they cannot control what you do outside those boundaries. Hence "legal" but obviously skirting their BAN on drones. I am sure they frown when the arrogant drone owners fly in anyway.

 

[sar104]

The NPS has BANNED drones within their boundaries. Thats a pretty clear statement on what they think about drones.
They have only admitted that they cannot control what you do outside those boundaries. Hence "legal" but obviously skirting their BAN on drones. I am sure they frown when the arrogant drone owners fly in anyway.

I don't disagree with the sentiment of respecting the intent of preventing drones becoming a nuisance in National Parks (or elsewhere), but the law is clear. It is not "skirting" an NPS ban on drones because they do not have the authority to ban drones any more than they can ban manned flights - they can only ban activities (in this case takeoff and landing) within the parks.

 

[Cuervo]

think it is clear that flying in NPS is frowned upon. The fact that you can "skirt" the restriction and take off outside and fly in is an irresponsible act. Its not the take off and landing that the restrictions are in place for. So expect a confrontation if you do so, take your ticket, and see if you can beat it in court. If you have that time to waste. Better to go to the park gift shop and buy a couple postcards of photos you like. its not like your pictures will be any better quality anyway.
When you register with the FAA one of the few things you see is them asking you to not fly around populations and not over 400'. its not law, but in a sense you are agreeing to those restrictions by completing the registration.
With NFZ's, and Altitude restrictions, You are politely asked NOT to do it.
If you are the type of person that farts in elevators, or doesnt use deodorant, I wouldnt expect compliance from you.

"Thanks for this clarification"
I'm just being kind to sar104.

I worked in the Aldo Leopold Wilderness of New Mexico for several years as a trail maintenance crew boss and have seen it all with regards to the scoff laws. Anything and anytime a sad few thought they could get away with something they would. It ruins it for a lot of people when someone thinks they can push the envelope or that they're somehow special and the rules don't apply to them.
I could go on and on with the "there I was" stories, suffice it to say I'm exceptionally observant and if I see anyone skulking around and edging into mischief I'm more than delighted to call it in.

 

[ac0j]

I don't disagree with the sentiment of respecting the intent of preventing drones becoming a nuisance in National Parks (or elsewhere), but the law is clear. It is not "skirting" an NPS ban on drones because they do not have the authority to ban drones any more than they can ban manned flights - they can only ban activities (in this case takeoff and landing) within the parks.

And that is the way things are. They dont want them, but they cant stop them. They can ask you not to, but if you are determined and not willing to abide by their wishes, you can do whatever you want. I have said this MANY times before on this forum. " Just because you can, doesnt mean you should".
Remind me not to get into an elevator with you!

 

[msinger]

Conclusion: the smart battery functions appear to have superseded the user-defined battery levels, and those are now simply warnings, even though the manual continues to state otherwise and the logged data imply that it should land at the critically low warning level.

The smart battery functions aren't really superseding anything. Those functions are independent from the battery warning settings in DJI GO.

As the battery depletes it issues the expected warnings at 30% and 20% but, contrary to the manual (p. 15) that states that it will autoland at the critical low battery warning level, it did not do so.

Here's the section of the Mavic Pro manual you're referencing:



The table at the bottom is attempting to explain what's being shown in the battery level indicator example above it (which is the indicator that appears at the top of DJI GO). DJI's use of the word "warning" is meant to describe the red and yellow sections of the battery level indicator (not the user defined warnings in DJI GO).

Check out this video for a clear explanation of what the Mavic Pro manual is attempting to explain:

 

[Cuervo]

And that is the way things are. They dont want them, but they cant stop them. They can ask you not to, but if you are determined and not willing to abide by their wishes, you can do whatever you want. I have said this MANY times before on this forum. " Just because you can, doesnt mean you should".
Remind me not to get into an elevator with you!

Don't wear deodorant into the wilderness either, because bears.
They're particularly attracted to Old Spice.

 

[ac0j]

Don't wear deodorant into the wilderness either, because bears.
They're particularly attracted to Old Spice.

I think you mean AXE. LOL!