hello to everyone while I was on holiday in the Dolomites I found a serious problem on my mavic pro regarding the altitude imposed by dji on its application of maximum 500 meters above the ground, the problem was' the throat of a dolomite river of 600 meters in height I did all the takeoff procedures and I started to go down the river with the mavic, I realized that the mavic was descending altitude warning me that I was over 500 meters set by dji when the drone arrived at 500 meters and 'stopped and here comes the problem of being 600 meters tall from him, so the drone could not come back to me
now I ask you what I was wrong?
why does not the drone calculate the height of the sea level from where it takes off?
in my opinion the mavic must also have sensors in the take-off control so the mavic always understands the actual height the pilot is !!!
is there a way to get the drone back from the pilot when the pilot is higher than the drone ???
sorry for my bad English
hello and thanks for the answers

Hi fans6b030321,

Strange, i never read that flying down from takeoff postion is limited to 500 meters. Drone should fly down as far as you want, and go up again.
500 meters limit is calculated from takeoff position and only upwards, if i am right.

BUT if you landed somewhere (let say 600 meters lower that the original takeoff position) and takeoff again than that new takeoff point is your zero reference and drone will not go higher than 500 meters! Was this the case?

I read a mishap on here where flying down into a cave and loosing GPS signal (so in OPTI mode) the drone will only fly 5 meters higher from the height when go into OPTI.
This can be very akward, getting drone back highter is impossible!! when GPS signal is not getting back to the drone.



cheers
JJB

hello I never landed after take-off, the drone went down alone at the altitude set 500 meters
I think the drone if he starts at 600 meters reads that height but when he is in the air he realizes that he is 600 meters away and not 500 so he drops below the set altitude
if there was a height control even on the control this problem can not be there

jprr Posted at 2018-8-22 11:11
hello I never landed after take-off, the drone went down alone at the altitude set 500 meters
I think the drone if he starts at 600 meters reads that height but when he is in the air he realizes that he is 600 meters away and not 500 so he drops below the set altitude
if there was a height control even on the control this problem can not be there

Hi jprr,

Sorry, do not understand your first sentence. You went down from your position and what happend at minus 500 meter?

cheers
JJB

I agree with JJB and this sounds surprising to me as well. Would you mind uploading the relating flightrecord (this is stored in a DJI subfolder of your mobile device) to this site and share the link with us?: http://www.phantomhelp.com/LogViewer/Upload/

JJBspark Posted at 2018-8-22 10:56
Hi fans6b030321,

Strange, i never read that flying down from takeoff postion is limited to 500 meters. Drone should fly down as far as you want, and go up again.

That’s not correct, if your flying into a cave with weak gps and downward vision is active then you are within 36 ft of the bottom of cave max, so you will have plenty of height available to climb back out, ie if you lower aircraft to minus 36ft then you can climb to 5 metres above 36 ft,  if downward vision is not available and you have weak gps you can climb to 30 metres above take off. So you should never be in a position where you cannot climb higher than take off position.

ci sono problemi se scrivo in italiano ?

the mavic from the position where I was and took off and dropped to 500 meters and I could not climb more than 600 meters so I too fell to 500 meters and the drone managed to land


the mavic from the position where I was and took off and dropped to 500 meters and I could not climb more than 600 meters so I too fell to 500 meters and the drone managed to land

the mavic from the position where I was and took off and dropped to 500 meters and I could not climb more than 600 meters so I too fell to 500 meters and the drone managed to land

from what I remember I managed to climb a few meters above 500 thanks to the sport mode

Wachtberger Posted at 2018-8-22 11:25
I agree with JJB and this sounds surprising to me as well. Would you mind uploading the relating flightrecord (this is stored in a DJI subfolder of your mobile device) to this site and share the link with us?: http://www.phantomhelp.com/LogViewer/Upload/

I'm looking for her

hallmark007 Posted at 2018-8-22 12:21
That’s not correct, if your flying into a cave with weak gps and downward vision is active then you are within 36 ft of the bottom of cave max, so you will have plenty of height available to climb back out, ie if you lower aircraft to minus 36ft then you can climb to 5 metres above 36 ft,  if downward vision is not available and you have weak gps you can climb to 30 metres above take off. So you should never be in a position where you cannot climb higher than take off position.

Ofcourse its correct what i was saying! ( if 5 meters equals 16 feet... ) Must be my bad english or your 'wrong' interpretation.
In GPS mode you can fly down and down and up and up.

Weak GPS into OPTI mode means you can fly higher upto ** feet from the ref height, the takeoff height that is. That is not what Toby told us what happend.manual data
** 16 feet max with weak GPS and downward vison activated
** 98 feet max with weak GPS and downward vision not activated


So its strange what happend and i hope to see that flightlog.

If this drone had landed (bad idea but some do) 600 meters lower than takeoff point, the normal height limit (user value, OP case 500 meter i guess) limit is refreshed and referenced form that new position. That why i asked to get the picture what have happened.

So its a strange puzzle ; JPPR flew down into a cave (in GPS mode i guess), down to about 600 meters, no landing ect, and flying upward to 500 meters from his lowest point! and drone could not reach initial takeoff point. Am i correct Toby??

cheers
JJB

JJBspark Posted at 2018-8-23 00:34
Ofcourse its correct what i was saying! ( if 5 meters equals 16 feet... ) Must be my bad english or your 'wrong' interpretation.
In GPS mode you can fly down and down and up and up.

Maybe not landed, but Home point set initiated at -600 mtr. Same problem will occur. I think flightlog is needed to determine what happened.

chiplifter Posted at 2018-8-23 00:58
Maybe not landed, but Home point set initiated at -600 mtr. Same problem will occur. I think flightlog is needed to determine what happened.

Do you really think that the OP resets it HP when his drone flys 600 meter below him??
Or do you know why the app will initiate a new HP by itself?

Flightlog will tell us the whole story!

JJBspark Posted at 2018-8-23 01:07
Do you really think that the OP resets it HP when his drone flys 600 meter below him??
Or do you know why the app will initiate a new HP by itself?

I can’t tell. Flightlog needed to be sure what happened.
Btw. Is your flightlog program still avail for download? I have a mac, but would like to try to run it on VM Ware.

The mavic uses barometric height about takeoff position (QFE).  Unless you're low enough for the VPS to kick in (30ft or so) it has absolutely no idea how high it is over the ground below it.  And it doesn't care.
GPS altitude is only used to encode the IPTC data on the images (because its grossly inaccurate).

People fly mavics off cliffs all the time.  All that happens is the altitude displays a negative number once its below takeoff height.  And the limit is set to 500m *above takeoff height*.

All i can think of here is dynamic or manually set home point "resetting" in flight.  Flight logs would help here.

chiplifter Posted at 2018-8-23 01:15
I can’t tell. Flightlog needed to be sure what happened.
Btw. Is your flightlog program still avail for download? I have a mac, but would like to try to run it on VM Ware.

same here, cannot tell either with just the info given, wait to see that flightlog

Yes, download still there (soon update version), see https://forum.dji.com/thread-145649-1-1.html

cheers
JJB

JJBspark Posted at 2018-8-23 02:05
same here, cannot tell either with just the info given, wait to see that flightlog

Yes, download still there (soon update version), see https://forum.dji.com/thread-145649-1-1.html

Thanks I will download it and will try.

gnirtS Posted at 2018-8-23 01:51
The mavic uses barometric height about takeoff position (QFE).  Unless you're low enough for the VPS to kick in (30ft or so) it has absolutely no idea how high it is over the ground below it.  And it doesn't care.
GPS altitude is only used to encode the IPTC data on the images (because its grossly inaccurate).

Hi gnirtS,

500 meter limit? wich limit do you mean?
in the manual i read max height = 5000 meter above sea level.

cheers
JJB

JJBspark Posted at 2018-8-23 02:12
Hi gnirtS,

500 meter limit? wich limit do you mean?

500m above takeoff location.  The altitude ceiling the software imposes.
An unmodified drone is hard limited to 1640ft/500m pressure altitude above takeoff location.

As opposed to the maximum operating pressure altitude in the manual (ie taking off from 5000m although we know it works far higher).

gnirtS Posted at 2018-8-23 02:25
500m above takeoff location.  The altitude ceiling the software imposes.
An unmodified drone is hard limited to 1640ft/500m pressure altitude above takeoff location.

Thanks gnirtS, learning all the time, have never read that limit somewhere.

I never fly higher than 120 meters, high enough for nice pictures etc. And ofcourse legal limit in my country.

cheers
JJB

Just remove the limits placed by DJI. Problem solved. Research it; I have done this.

Why bother - the problem he describes is caused by something else not an altitude limit.

JJBspark Posted at 2018-8-23 00:34
Ofcourse its correct what i was saying! ( if 5 meters equals 16 feet... ) Must be my bad english or your 'wrong' interpretation.
In GPS mode you can fly down and down and up and up.

I read a mishap on here where flying down into a cave and loosing GPS signal (so in OPTI mode) the drone will only fly 5 meters higher from the height when go into OPTI.
This can be very awkward, getting drone back higher is impossible.

Above is what I was correcting, it’s not awkward getting drone back, if you have weak gps, if you enter opti mode, you can still climb to 5m above take off, so it’s not a problem.

sorry for the delay however now I change the problem let's see if we get to a point:
if I take off at 500 meters of height and leave the drone in stationary flight
I move with the control at an altitude of 600 meters the drone tells me that I have reached the maximum height limit and this is the problem !!!!
I found the flightlog and I realized that the GPS signal was very bad at most 4 satellites and above all that during take-off did not exactly indicate its real height from the ground ..
I'm trying to figure out how to get the flightlog out of my cell phone sorry but I do not use mac  

JJBspark Posted at 2018-8-23 02:28
Thanks gnirtS, learning all the time, have never read that limit somewhere.

I never fly higher than 120 meters, high enough for nice pictures etc. And ofcourse legal limit in my country.

and just to clarify I do not need to go high to fly happily with my drone but I do not want to find myself in situations like this for a problem that maybe you do not know well

jprr Posted at 2018-8-23 08:11
sorry for the delay however now I change the problem let's see if we get to a point:
if I take off at 500 meters of height and leave the drone in stationary flight
I move with the control at an altitude of 600 meters the drone tells me that I have reached the maximum height limit and this is the problem !!!!

Hope you will succeed in uploading the flight log.
I am an happy Android user too!

With a good GPS signal your drone can fly up 500 meters higher than takeoff height.
So if you climb 100 meter up yourself the drone can fly there as well.

GPS signal bad.....getting more curious about that flight log!

cheers
JJB

JJBspark Posted at 2018-8-23 08:25
Hope you will succeed in uploading the flight log.
I am an happy Android user too!

unfortunately I bought an iphone 6 plus to fly with the mavic I use it only for that

LINK       https://mega.nz/#!fzw31JhQ                                                                     
key :          !lWNHmPS7DDvG4OyPou3q95oiOAISlvAdj0BCe-W1_hI


I made a video of the flight with the link and the key to enter
sorry for now I could only find this
from what you see in the video on the left does not even seem the true height and I guarantee that the mavic was flying over the river 500 meters from the ground when it all happened
perhaps because of the sun I have not seen well what he told me and perhaps for this reason I made mistakes, I would like to understand what I did wrong

you tell me if you see thanks

jprr Posted at 2018-8-23 08:52
unfortunately I bought an iphone 6 plus to fly with the mavic I use it only for that

You will only find the correct answers by examining your flight log, as jjb above has already told you, they are embedded in your phone if you go to link instructions are all there.

We need the .txt file off the mobile device.  A video tells us nothing.