Just viewed my log and after hitting RTH (HAVE RTH SET TO 30M) I was at 20 meters. Right after hitting RTH the screen indicated I hit RTH and sensors would be deactivated for return home then it dropped 1 meter and then right after another meter @ 2 total. Was stable and holding flight prior to hitting RTH (not too windy outside). Hit an obstacle at 18m mark and blew props off and slammed into ground. 2 motors gone for sure and gimbal snapped of. Full body damage and sensor as well. I have hit RTH before and first thing it does is climb to 30m then head straight bearing home. Do I have a leg to stand on? Also nothing else touched but RTH had 18 satellites connected etc. All was well.

How close was the drone to you when you hit RTH?
If it is within 20 meters (65 feet) of home point it will simply land where it is.
What was the battery level?

I was possibly close to the home point so I will look into that for sure. I still had over 9 minutes flight time left. Thank you for your comment I was unaware of the home point being close resulting in it just coming straight down.

I'm sorry to hear. It would be best to get in contact with the North American Support team to have the unit sent in for further evaluation and repair. You would also want to ensure that your Go app flight records are synced in case there are any issues extracting the flight data from the aircraft itself.

fans2c71a9eb Posted at 2017-4-20 19:00
I was possibly close to the home point so I will look into that for sure. I still had over 9 minutes flight time left. Thank you for your comment I was unaware of the home point being close resulting in it just coming straight down.

I have personally never liked that.

RTH should do exactly what it is supposed to do.

We lobbied to remove the CSC, let's lobby to remove that goofy landing when RTH.

Some people lose their bird, some people are just lazy but first of all you shouldn't have to guess what RTH is going to do.  Maybe youre a meter away from it being the right amount.


When you hit RTH it should do just that even if it's 20 inches from you. It is programmed to take of to a  certain point and land and that's what is should do.

I almost had a problem with that happening because it set a bad homepoint because I didnt know that the non LTE pads didn't have GPS and the wifi triangulation isn't as good and it was laying like 20 feet away and I could hear it. Different scenario but not landing where you know EXACTLY where it is is obviously dangerous.

Make RTH do what it's programmed to do.  We know when we want to land.

Sorry about your drone. Yes that sounds like the 20m/65feet RTH limit that will simply send the drone straight down where it is. Working as a professional in user friendly design and interfaces, my opinion is that it's a serious and dangerous design flaw because it's not intuitive and makes RTH behave in a way that the user really has no reason to expect. That "feature" has probably destroyed many hundreds of DJI drones. It's not even explained well in the manual.

Fruxen Posted at 2017-4-20 21:52
Sorry about your drone. Yes that sounds like the 20m/65feet RTH limit that will simply send the drone straight down where it is. Working as a professional in user friendly design and interfaces, my opinion is that it's a serious and dangerous design flaw because it's not intuitive and makes RTH behave in a way that the user really has no reason to expect. That "feature" has probably destroyed many hundreds of DJI drones. It's not even clearly explained in the manual.

'It's not even clearly explained in the manual.'

Actually it is explained properly in all the manuals I have read.

"Aircraft automatically descends and lands if RTH is triggered when the aircraft flies within a 20 meters (65 feet) radius of the Home Point."

What is unclear about that?

Geebax Posted at 2017-4-20 21:55
'It's not even clearly explained in the manual.'

Actually it is explained properly in all the manuals I have read.

I just changed my post to that it's not explained WELL in the manual.

"Aircraft automatically descends and lands if RTH is triggered when the aircraft flies withing a 20 m radius."

That can easily be interpreted like a normal RTH landing back to the take off point, especially since that is what you would expect.

Despite all the opinions that it must have been the 20 metre thing, this is very unlikely.
Who uses RTH when their Phantom is less than 66 feet away?  (apart from a nervous newbie experimenting with RTH for the first time)

Although the people suggesting the 20 metre issue are wrong, they are closer to the answer than they realise.
On page 15 of the manual, the sentence following the <20 metre distance "feature" is probably the explanation for what you saw.

Aircraft automatically descends and lands if RTH is triggered when the aircraft flies within a 65 feet (20 meters) radius of the Home Point. Aircraft will stop ascending and immediately return to the Home Point if you move the left stick if the aircraft reaches 65 feet (20 meters) altitudes or beyond during Failsafe.

If you upload your flight data to http://www.phantomhelp.com/LogViewer/Upload/
..  and post a link to the report it provides, the flight data will probably explain the incident.

ArtistFirst Posted at 2017-4-20 21:50
I have personally never liked that.

RTH should do exactly what it is supposed to do.

Home position (as recorded when taking off and before) is given by the quad GPS, not the tablet.

Labroides Posted at 2017-4-20 22:59
Who uses RTH when their Phantom is less than 66 feet away?  (apart from a nervous newbie experimenting with RTH for the first time)

I do, when I take off I choose a place to take off from that is also suitable for landing, when I want to land I press RTH to position it over the landing place and then land.  Why should I bother to carefully adjust the aircraft's position manually in order to land on the landing place when it could do it itself?  This rule just means that I have to fly the aircraft 20m away before I can press RTH!   

Yes, sometimes I do want to just land where it is, that should be an option, maybe pressing RTH while holding the throttle down could just land  (P.S. Don't try this - it might actually work!) in the same way that you can cancel the RTH height gain if you wish, and I often do.

And sometimes I like to fly and land manually, but normally my P4 is a camera for photography/videography, not a radio control aircraft flown for the enjoyment of flying.

Nigel_ Posted at 2017-4-21 00:10
I do, when I take off I choose a place to take off from that is also suitable for landing, when I want to land I press RTH to position it over the landing place and then land.  Why should I bother to carefully adjust the aircraft's position manually in order to land on the landing place when it could do it itself?  This rule just means that I have to fly the aircraft 20m away before I can press RTH!   

Yes, sometimes I do want to just land where it is, that should be an option, maybe pressing RTH while holding the throttle down could just land  (P.S. Don't try this - it might actually work!) in the same way that you can cancel the RTH height gain if you wish, and I often do.

OK ... no-one except you and timid newbies trying RTH for the first time.

If you want to land, you don't have to hit RTH, you could use the autoland feature or even pull the left stick downwards.
Everyone else using the RTH feature does so because they want their Phantom to ... you know ... return to ... home.

Labroides
"Who uses RTH when their Phantom is less than 66 feet away?"
"Everyone else using the RTH feature does so because they want their Phantom to ... you know ... return to ... home."

Yes people use RTH because they want to make their Phantom... you know... return to the home point. You answered your own question, thanks keep it up!

I also find it strange (and potentially dangerous) that the RTH button is (in effect) redesignated as an autoland button when within 20m of home point.

Does anyone understand the rationale for DJI setting it like that? If it was 5m, or 3m or something smaller I could understand that it might relate to GPS error margins meaning it not worth ascending many 10s of meters just to descend again at almost the same position. But 20m away??

Simon Child Posted at 2017-4-21 02:10
I also find it strange (and potentially dangerous) that the RTH button is (in effect) redesignated as an autoland button when within 20m of home point.

Does anyone understand the rationale for DJI setting it like that? If it was 5m, or 3m or something smaller I could understand that it might relate to GPS error margins meaning it not worth ascending many 10s of meters just to descend again at almost the same position. But 20m away??

I would also prefer a more consistent behavior, but can think of some reasons why the programmers implemented this:
If you hit RTH you want the quad to return to you. If it were a 10 m distance and it would first rise to 30 m. if would be moving away from you.
Also, if you lift-off in the garden or near buildings, it would be safer just to descend.

I think no one has a logical explanation, about the famous 20 meters

Rene vd Meer Posted at 2017-4-21 02:45
I would also prefer a more consistent behavior, but can think of some reasons why the programmers implemented this:
If you hit RTH you want the quad to return to you. If it were a 10 m distance and it would first rise to 30 m. if would be moving away from you.
Also, if you lift-off in the garden or near buildings, it would be safer just to descend.

"If you hit RTH you want the quad to return to you."

But it makes no difference to anyone because no-one except a timid new flyer trying their first RTH to close and Nigel_ will ever experience this.
For everyone else, when their Phantom is 66 feet away or closer, they simply fly it back.

Simon Child Posted at 2017-4-21 02:10
I also find it strange (and potentially dangerous) that the RTH button is (in effect) redesignated as an autoland button when within 20m of home point.

Does anyone understand the rationale for DJI setting it like that? If it was 5m, or 3m or something smaller I could understand that it might relate to GPS error margins meaning it not worth ascending many 10s of meters just to descend again at almost the same position. But 20m away??

Because at one time a lot of people use to panic when Aircraft was only 20 feet and all of a sudden it just took to the sky, new users then panicked and all sorts of bad stuff happened, that's my thinking on it.

If it's within 100 feet why would you not just fly it home that then would become consistent. Just what I think.

I suspect it is to do with indoor flying, it reduces the chance of a beginner flying it into the ceiling/roof.

However it would be much better to have it as an option, then the beginner flying it into the roof would be choosing to do so, while all the other beginners that have it land in the garden pond would no longer have a problem, and I wouldn't have to remember to check the distance to home figure to know if the RTH button would RTH or would auto-land instead.

Ulysse Posted at 2017-4-20 23:12
Home position (as recorded when taking off and before) is given by the quad GPS, not the tablet.

Correct, but when it is returning, it uses wifi triangulation or something to find out exactly where YOU are as a redundancy.  It's like double GPS and gives you a much better landing mark.

ArtistFirst Posted at 2017-4-21 11:14
Correct, but when it is returning, it uses wifi triangulation or something to find out exactly where YOU are as a redundancy.  It's like double GPS and gives you a much better landing mark.

Uhm.. Where do you see this at? It records the homepoint through GPS co-ordinates on the drone UNLESS you reset it to the controllers GPS co-ordinates.. The "triangulation" you are referring to is GPS. The only other thing that the P4P and Mavic do is take pictures of the ground at homepoint while taking off.. If your tablet device does not have GPS, it will not allow you to record your location as the new home point. Wifi has nothing to do with homepoint settings.

I agree the 20m RTH 'feature' should be eliminated (as I have said in months back).
If you want to RTH, use RTH and that is exactly what it should do, wherever it is.  If you want it to autoland where it is, use the autoland function.
These features should just do what they do without changing behavior based on some arbitrary distance reading.
As far as RTH indoors, I hope you have Read The Flight Manual enough to know to change how the RTH (failsafe) function behaves (hover) and change the RTH altitude to some appropriate setting (still not a good idea to RTH indoors though due to spotty GPS signal).   I just don't fly indoors, fixed.

fans2c71a9eb Posted at 2017-4-20 19:00
I was possibly close to the home point so I will look into that for sure. I still had over 9 minutes flight time left. Thank you for your comment I was unaware of the home point being close resulting in it just coming straight down.

Most crashes occur because people fail to read the documentation related to using their drone.
For my P3S I downloaded the 54 page PDF file and read through it a few times, going back over several things.

Not knowing about the 20m distance using RTH simply means you never bothered to read the manual. It's very exciting to just go out and fly.  But things that fly tend to hit the ground hard when pilot error or a malfunction occurs.  Often cases the malfunctioning part is the pilot and not the drone.

ArtistFirst Posted at 2017-4-21 11:14
Correct, but when it is returning, it uses wifi triangulation or something to find out exactly where YOU are as a redundancy.  It's like double GPS and gives you a much better landing mark.

Not at all ...RTH does not use any additional wifi triangulation and I wonder where you got that idea.
It uses only the GPS coordinates for the home point that the Phantom recorded at launch time.
Home point is a point and using dodgy wifi to come up with a different point won't do anything to give you a much better landing mark.
Such a system (if used) would be more likely to give you a much less accurate location and then what's the Phantom going to do with two different points?

Labroides Posted at 2017-4-21 16:53
Not at all ...RTH does not use any additional wifi triangulation and I wonder where you got that idea.
It uses only the GPS coordinates for the home point that the Phantom recorded at launch time.
Home point is a point and using dodgy wifi to come up with a different point won't do anything to give you a much better landing mark.

Uses wifi triangulation to transmit to the RC the landing location if the RC unit does not have a GPS transmitter (i.e. an RC using an iPad mini that does not have GPS like one without cell).  Rare but some don't.

Mobilcams Posted at 2017-4-21 12:34
Uhm.. Where do you see this at? It records the homepoint through GPS co-ordinates on the drone UNLESS you reset it to the controllers GPS co-ordinates.. The "triangulation" you are referring to is GPS. The only other thing that the P4P and Mavic do is take pictures of the ground at homepoint while taking off.. If your tablet device does not have GPS, it will not allow you to record your location as the new home point. Wifi has nothing to do with homepoint settings.

I never said the contrary.  I have been misunderstood here. I know how GPS hompoints are initially drawn and dynamically changed.  Wifi Triangulation is used on the return to help get it as close as possible if you DON'T have GPS on the RC.

Ulysse Posted at 2017-4-20 23:12
Home position (as recorded when taking off and before) is given by the quad GPS, not the tablet.

I know that. I am talking about the landing. And I DO COMPLETELY understnad that the bird still knows the GPS point it set at the beginning of the flight but ask anyone that has landed with a WIFI only unit if it's better with a GPS one or a WIFI one and you will see.  But with that....
****Kindly and politely removes himself from conversation.


I have a lot of stuff to do right now and can't do this.  I respect all of your thoughts and appreciate them but i will not be partaking in this conversation because I am busy as hell.

Good luck with your bird brother.

ArtistFirst Posted at 2017-4-25 11:34
Uses wifi triangulation to transmit to the RC the landing location if the RC unit does not have a GPS transmitter (i.e. an RC using an iPad mini that does not have GPS like one without cell).  Rare but some don't.

Where did you get this "information" from?
If you initiate RTH, your Phantom comes back to the point it recorded at launch.
It doesn't do anything to modify this or look for a "better" location.
Test it yourself - launch - move well away and RTH.
Your Phantom will go back to where it launched, not wherever the controller is now.
If it could somehow follow you, DJI wouldn't give you the option to reset home to the controller.

Your idea about return accuracy with GPS/non-GPS tablets is complete bunk.
You are probably confused by the variable inaccuracy of consumer GPS.
Do ten RTH landings with whatever tablet you like and you'll find the Phantom landing +/- about 2.5 metres - sometimes very close and other times further away.
This is due to the way consumer GPS works and has nothing to do with the tablet you use.
The Phantom always and only comes back the the point it stored at launch, definitely not any enhanced, modified, improved home point.

Labroides Posted at 2017-4-25 14:43
Where did you get this "information" from?
If you initiate RTH, your Phantom comes back to the point it recorded at launch.
It doesn't do anything to modify this or look for a "better" location.

Ok, I'll just give you a situation. If you lost most of your satellites, to better help figure out where the HP is it would use "WiFi Triangulation".

It's in the manual if you read it. Either way, it doesn't matter to me. This is not an argument I care to have. Maybe you're right. How about I just say "you are right", thank you for fixing me on this issue.  I've been wrong before.  They crucified me but whatever.

I think they should have a sticker on the remote RTM button saying "do not operate within 65 ft" just one of the peel off stickers,

ArtistFirst Posted at 2017-4-26 09:12
Ok, I'll just give you a situation. If you lost most of your satellites, to better help figure out where the HP is it would use "WiFi Triangulation".

It's in the manual if you read it. Either way, it doesn't matter to me. This is not an argument I care to have. Maybe you're right. How about I just say "you are right", thank you for fixing me on this issue.  I've been wrong before.  They crucified me but whatever.

"If you lost most of your satellites, to better help figure out where the HP is it would use "WiFi Triangulation".

If you lose GPS, that's all there is to it.  Your Phantom doesn't switjhc to an alternative.

"It's in the manual if you read it"   

Really?   I've been searching and need a little help.
Please point me in the right direction to find this gem.

Labroides Posted at 2017-4-26 18:30
"If you lost most of your satellites, to better help figure out where the HP is it would use "WiFi Triangulation".

If you lose GPS, that's all there is to it.  Your Phantom doesn't switjhc to an alternative.

Location services in iOS uses a combination of built in GPS, cellular triangulation, and even wifi.

ArtistFirst Posted at 2017-5-3 17:43
Location services in iOS uses a combination of built in GPS, cellular triangulation, and even wifi.

BUT, the Phantom doesn't access any location data from the phone or tablet unless you want to reset your home point to the current location of the device or do follow-me flight.
For all other flying, the Phantom will return to the home point it recorded without any consideration for whatever location data the tablet has.
Why would it?
It has a perfectly good location for the homepoint stored in its memory.

Labroides Posted at 2017-5-3 17:50
BUT, the Phantom doesn't access any location data from the phone or tablet unless you want to reset your home point to the current location of the device or do follow-me flight.
For all other flying, the Phantom will return to the home point it recorded without any consideration for whatever location data the tablet has.
Why would it?

This is correct.

But again, the software can and does malfunction from time to time.

If you get a homepoint at a bad spot, or even accidentally set one at the bird, OR if you walk away or float away on a boat, being able to set the home point is a VERY IMPORTANT FEATURE!

I am not sure why people aren't grasping the importance of being able to set dynamic homepoints. In the event of an accidental or software glitch, you could trick the intelligent battery and software to thinking it is FAR from home.