I was flying my PRO under a canopy of trees when the RTH message informed me I have 10 seconds before the aircraft would start the RTH sequence. I had no time to cancel this action as the aircraft immediately ascended to 30 meters. Unfortunetly the tree top canopy was only 20 meters in height. My phantom 3 PRO suffered two crashes at that time. The first as the aircraft crashed into the upper braches, and the second occured when the aircraft crashed to the ground.

Sorry for your troubles!  Battery too low?

Sorry about that crash . Please contact your dealer or support center for a repair .

DJI-Patrick Posted at 2015-12-29 01:55
Sorry about that crash . Please contact your dealer or support center for a repair .

I would have pushed the RTH button if I had the time to. The aircraft did not wait the 10 seconds before ascending, it took off like a bat out of hell. Fortunately I purchased my P3P at Best Buy and they exchanged it without question.

mjlstudios Posted at 2015-12-29 19:36
I would have pushed the RTH button if I had the time to. The aircraft did not wait the 10 seconds  ...

I was just remind you that you can stop the ascending by this way . Nice to hear that you'll get a new aircraft .

Mine did the same thing earlier today.  Being careful, I brought it down from altitude when the battery got to 30%.  I had it right in front of me ready to land.

Instead of landing I kept it hovering, showing my dad how I could maneuver it along the ground.  I was literally landing it with the left stick pulled completely down, and it no more than 2 feet from landing (probably less) and the app starts a faster warning beep.  Without giving me any time to cancel or override it, it Airbus A320'ed itself into a tree branch at about 40 feet.

2 feet from the ground with the pilot currently descending and it overrides and decides to use what little battery is left to launch it at maximum power straight up? ... what a great idea!

Lots of bad assumptions went into that control philosophy... Your car is about to run out of gas and you haven't parked it... let's program it to go full throttle and make a blind J-turn, that will help.  If there isn't a way to disable it, there needs to be.  I would rather risk the battery dying while it is still in the air than have it launch itself back up without giving me a chance to stop it.

What do people do if they are flying indoors?  Lookout ceiling.

Let that be a lesson to everyone...if you get a low battery warning, land & disarm the motors asap.

"Lots of bad assumptions went into that control philosophy... "

No, not bad design at all, it did exactly what it was programmed to do, and most would agree it did the right thing. You can cancel it by pressing the RTH button, but you probably had not practised doing that.

Geebax Posted at 2015-12-30 12:03
"Lots of bad assumptions went into that control philosophy... "

No, not bad design at all, it did e ...

Agree. I Always run my battery down and when the RTH kicks in i cancell it immediately and keep on flying until it auto lands. You have to be ready for it though else if it catches you unawares then i see problems.

You can cancel it either by pressing "Cancel" in the notification that pop-ups or pressing the RTH button on the controller. It doesn't start inmediatly, you have at least 3 seconds to cancel it (i've never wait more than that, but according to the manual it's 10 seconds)

perryherndon Posted at 2015-12-30 06:15
Mine did the same thing earlier today.  Being careful, I brought it down from altitude when the batt ...

My P3P never set a home point when i Fly indoors because it does not connect to any satellites.

I received no such warning.  It said return to home initiated or something to that effect and went full boogie straight from one foot off of the ground (I watched the video) straight up into a tree that it hit as I was hitting the cancel button.  There might have been a popup/countdown on the screen? (but I have read some threads that indicate that is not the case).

I guess all you guys stare at the screen when the aircraft is hovering mere feet in front of you?  I was flying by sight... because it was low and right in front of me... which is common sense.  Actually, I have never flown mine out of sight.  I use line of sight for flight nearly exclusively ... like an RC plane, and only use the video to line up my camera shots, check my altitude, and see the view.  I don't use the video to fly - especially not under those circumstances, so I would not have seen any silent popup warning that it was about to seppuku.  All I heard was the same beep warning that I heard which led to me bringing it down low from the primary flight so a safe location for me to piddle... right up until the female voice said something about return to home and it fired straight up into a tree.

So, is it my fault?  Yeah, I guess so...  for not testing every possible way the thing might decide it knows better than me, take control, and wreck itself.  I spent my time getting proficient with the aircraft, not becoming an expert in overriding bad failsafe implementations.  I have never tested/used RTH, auto takeoff/auto land because I have never needed any of them.  My fault was trusting the logic of the programmers too much - that an aircraft system that advertises features for flying low (and indoors) would not unexpectedly do this.

As far as control philosophy... I have no problem with the "feature" being included, but let me disable it in the app at my own discretion instead of making me play chicken with disaster if I want to use the end of my battery flying low to the ground right in front of me.

If you can turn it off, let me know how.  I don't see where that is an option.  I will turn it off for every flight where I don't intend to (irresponsibly?) send the thing a mile away out of sight (which would be every flight).  I would be far more accepting of an event that I caused through my own irresponsibility compared to the easter egg gotcha, here let us help you with that problem you don't actually have, that I got yesterday.

Not a bad design?  That's arguable.  Someone went to a lot of trouble to include this so as to save the aircraft when there is a failure of the control system, operator error, or irresponsible flight and the battery is about to die.  There are two examples in this thread (and many others if you search) of people without any of those issues having their aircraft commit hari kari in a vain attempt to save itself when it didn't need saving.  I don't know how many a non-commanded, involuntary, low battery based RTH has saved one of these, but I bet the statistics aren't too glowing if you factor in the number of times that has led to a software knows better than you crash.

Examples:
This thread (2 cases).
http://forum.dji.com/thread-23055-1-1.html
http://www.phantompilots.com/thr ... rash-landing.47670/
http://www.phantompilots.com/thr ... first-flight.41427/
http://www.inspirepilots.com/thr ... rmware-v1-3-0.4737/
http://forum.dji.com/thread-35837-1-1.html
http://forum.dji.com/thread-32813-1-1.html

That was just with one quick search.

Good warning for all....I'm on a farm and fly around/under lots of trees and the RTH feature is a concern of mine too.  Very nice feature, but you have to be ready if it kicks in.  My first experience was when I had the distance limited as a beginner, got outside that range and RTH kicked in.  Spun up to 100' quickly and I was fortunate to be away from the trees.  Lesson learned!  

Good luck and thanks for sharing!

The good news is I spent the evening repairing it and it was back in the air this morning...

New blades (of course).  I didn't need a new body.  I fixed the bend and stresses in the original with a hair dryer.  I was able to epoxy the thread inserts back in.  Other than a loss of slickers and some stressing of the plastic, you can't tell anything happened.

It would be nice if you had the option to switch off RTH on low battery warning in the software before flight.  Why not have it?  Same for anything designed to protect the battery should be optional as well IMO.  What's the advantage to switching off the battery when it normally condemns the drone to certain death?

What height do you guys set your RTH at? I'm new and just curious what a go number to live by would be.

theronmalone Posted at 2015-12-31 05:08
What height do you guys set your RTH at? I'm new and just curious what a go number to live by would  ...

The stock height is fine if you are flying in an open area. You should always set the RTH altitude according to your flight environment. if you around obstacles, set the RTH higher than those obstacles.

DJI-Ken Posted at 2015-12-30 15:58
The stock height is fine if you are flying in an open area. You should always set the RTH altitude ...

Thanks Ken! Before your reply I just changed it to 50m. Those trees just seem taller to me for some reason.

i set it to 50 meters, because i live in a town that only has trees and houses. so that clears everything

I bet the number 1 reason for RTH crashes is it hits something on the way home. That should be a part of your preflight checklist, set the RTH altitude

perryherndon Posted at 2015-12-31 05:05
I received no such warning.  It said return to home initiated or something to that effect and went f ...

"Not a bad design?  That's arguable.  Someone went to a lot of trouble to include this so as to save the aircraft when there is a failure of the control system, operator error, or irresponsible flight and the battery is about to die.  There are two examples in this thread (and many others if you search) of people without any of those issues having their aircraft commit hari kari in a vain attempt to save itself when it didn't need saving.  I don't know how many a non-commanded, involuntary, low battery based RTH has saved one of these, but I bet the statistics aren't too glowing if you factor in the number of times that has led to a software knows better than you crash."

The control software is designed to protect the aircraft and the investment of the person who owns it, and as such it does a better job of it than any other drone software I am aware of.  Personally, I want those features in there, and I bet it has saved more birds than it has lost.

As for the list of issues, sure, why not ask here how many people have had their aircraft saved by the RTH feature. After all you mostly get complaints here, not thank you posts. The list proves nothing.

If you don't want the feature, there is an SDK available, go ahead and produce a control app without it.

perryherndon Posted at 2015-12-30 13:05
I received no such warning.  It said return to home initiated or something to that effect and went f ...

Thanks Perry! You get it....sometimes things happen before you can react. I just think giving the pilot an opportunity to choose whether the aircraft  RTH   by their choice and not by software's choice. The software should warn the pilot the aircraft needs to RTH with a pop up window in the app with a "YES" or "NO" and let the pilot decide whether it is safe for the aircraft to RTH at that time.

DJI-Ken Posted at 2015-12-30 20:19
I bet the number 1 reason for RTH crashes is it hits something on the way home. That should be a par ...

So, based on this advice, I should have set my RTH altitude to what?  What RTH altitude would have prevented this impact?

What if my flight includes going under some tree branches or flying into and back out of a barn?  During preflight for such a flight to I would need to set my RTH at low battery to "Heck No!".  That setting does not exist.

It's a mandatory nanny that in those examples is unhelpful - instead harmful.

PerryH Posted at 2016-1-1 22:34
So, based on this advice, I should have set my RTH altitude to what?  What RTH altitude would have ...

You set your RTH higher than the tallest obstacle, if you are flying under trees than you set your RTH to land when it loses signal so it doesn't climb and hit a tree. The RTH will initiate when your battery gets too low as well, but at any time you can cancel RTH

DJI-Ken Posted at 2016-1-1 23:43
You set your RTH higher than the tallest obstacle, if you are flying under trees than you set your ...

That's what we (or at least I) am saying.

It did not give me any chance to cancel the RTH.  It shot straight up into a tree in an action that was simultaneous with the RTH warning.

And, if the controls will permit me to cancel it, why won't they permit me turn if off before it ever happens?

PerryH Posted at 2016-1-2 07:10
That's what we (or at least I) am saying.

It did not give me any chance to cancel the RTH.  It sh ...

I know on the low battery RTH it gives you a RTH warning and you can let it go into RTH or cancel RTH.

As I mentioned earlier... there might have been an on screen warning that RTH was about to commence ... a popup notification, a silent countdown, etc.  But, I was not looking at the screen.  The aircraft was right in front of me and I was landing it.  Why would I stare at the screen when I have the aircraft low and close and I am in the process of landing it?

All I heard was the female voice say something about return to home AT THE SAME TIME that control was taken from me and the aircraft rose, not at a gradual rate, but at its maximum climb rate, straight up into a tree limb.  There was no real opportunity for me to stop it.

Even if I was given all sorts of sufficient warning... does anyone really argue that as owners of $1000+ flying cameras, that we should not be given the option of turning off this "failsafe" before taking off?  These failsafes presume you are flying OVER obstacles.... Not to mention they assume that your takeoff spot/homepoint is clear to the sky.  I have flown in situations where I had to take off under tree cover then fly out from under it over a lake to safely ascend.  RTH in that situation means coming down into trees.

All that has been described here as solutions are really just workarounds for a bad assumption built into the control philosophy that we never fly under obstacles.
So I am left with a few options:
1) never fly under anything, ever.
2) If you risk flying under something ... make sure you have a lot of battery left.  Never use the end of a battery to fly low and close/practice movements if there is anything overhead.
3) If you risk ignoring 1 and 2, and want the entire flight time afforded by your battery... always stare at the screen, and always have one finger on the RTH button so you can be ready to cancel before the ascent of doom is initiated.

Those are all workarounds, and they limit the confidence in, and versatility and usefulness of, this platform.

Just curious why DJI has the RTH occur at near full throttle up.
So what would be the preferred procedure of RTH?
A vocal warning and an on screen warning that it needs to RTH and that the pilot should press the RTH
If the pilot doesn't then what? Warning again ? Land? Hover?
Would a much slower rise to RTH altitude be of any assistance?
Let's come up with a proposed solution , maybe DJI will see a benefit and implement it.

What part of common sense is missing with some of you?  You don't take off in a barn or under trees, etc.  You takeoff and land (homepoint) where sky is unlimited above you for 60 feet around the takeoff point.  That should be very clear from reading the descriptions of how it works.  If you can't do that, fly it manually or don't fly.  Also, HEED YOUR LOW BATTERY WARNING AND LAND!  If you wait until critical to land, you are asking for trouble.

AG0N-Gary Posted at 2016-1-3 00:12
What part of common sense is missing with some of you?  You don't take off in a barn or under trees, ...

You take off and land where ever you like. I fly indoors and out. If you fly any at all....you WILL crash...it is all in a matter of time.

AG0N-Gary Posted at 2016-1-3 05:12
What part of common sense is missing with some of you?  You don't take off in a barn or under trees, ...

But if you fly indoors, that's not an option.  Not only that, but if you fly under a 60ft ceiling RTH will crash your drone into it if you don't cancel quickly enough as you have no control over it until it reaches 20m (65.6ft).  Unfortunately, common sense just isn't enough!

If you're flying under a 60 foot ceiling, set your RTH to 50 feet!

AG0N-Gary Posted at 2016-1-3 15:43
If you're flying under a 60 foot ceiling, set your RTH to 50 feet!

Go ahead and try that in your app.  See what happens.

It will set it back to 20 meters... (~60 feet).  That is the minimum height.

Reading a number of these posts, what concerns me most is the time lapse in getting the warning and the initiation of the RTM. The manual say 10 seconds (seems like a reasonable amount of warning). But reading a number of posts it appears this may not be the case, or it is a visual warning only (on DJI GO screen I assume).

Has anyone tested this?

PerryH Posted at 2016-1-2 11:44
As I mentioned earlier... there might have been an on screen warning that RTH was about to commence  ...

Good list

I have been following:
2) If you risk flying under something ... make sure you have a lot of battery left.  Never use the end of a battery to fly low and close/practice movements if there is anything overhead.

that concept for year now flying along creeks , rivers, woods, etc.
I don't stare at my screen as I am flying LOS in treeded areas , but I do monitor my time mostly.
12 minutes and I am now monitoring battery closely and home at 30!
That extra minute or so past 30% doesn't excite me as much as my quad landing in one piece every time!
I had your uh oh moment myself , P2 has no warning other than , up it goes!
got that one on video btw..

That simple concept along some other simple ones have allowed me to still have my original Plus after hundreds and hundreds of flights a year later

good luck and have fun flying!

theronmalone Posted at 2015-12-30 16:08
What height do you guys set your RTH at? I'm new and just curious what a go number to live by would  ...

30 meters NO LESS
Happy flying

PerryH Posted at 2016-1-3 19:32
Go ahead and try that in your app.  See what happens.

It will set it back to 20 meters... (~60 fe ...

Sorry, mine is in temporary storage right now.  I don't remember reading that in the manual.  If it is true, my mistake.  It seems silly to have that sort of limitation, but maybe it does.

I set mine to 25m. I made this because of the flight environment I was in, low trees, 2-storey houses on the sides, wide open field. Then I got the dreaded "no signal" where the bird is not that far (about +/-70m) & still within line of sight. The RTH dialogue box kicked-in (about less 10 sec) & I gave it a go (no choice). From +/-65m up, it went down to 25m and lands itself a meter from homepoint. Geez, it just saved my bird. Then I power-off both bird & RC.
I closed the app, open it again, powered-on. The video feed came back. And I flew back. After some short run of few minutes (about +/-10m high), another dreaded "no signal" came again, and RTH again kicked-in but this time I didn't engage it because the bird was near me already. I was still able to control it, descend it near me and did a hand-catch.

Just tested this yesterday. 10 seconds warning (with sound) before it started to RTH. Didn't test the min height (sorry).
Inside a 15mts hangar (flying 2mts above ground) i had about 2 seconds to cancel RTH (once initiated the ascend) before it could hit the top.

PerryH Posted at 2016-1-2 06:44
As I mentioned earlier... there might have been an on screen warning that RTH was about to commence  ...

Aloha Perry,

     How come no one uses the hover option or land option of RTH?  It seems to me that there are environments for this - especially hover.  If people have a problem with uncontrolled ascent, just assign it to hover.  That is almost the same as canceling the RTH option.

Aloha and Drone On!