What is the furthest AND safest distance to fly P4 not height but distance, how reliable is the return mode in case of remote lost? I took mine 1,500 feet away today. Thought that was pretty far, however I'm reading that the P4 can go 3 miles!!?? Is that correct?? By my calculations that would over 15,000 feet away!!

depends on surroundings, I got out 4700 feet and still had full bars on RC while I was at my brothers in the country, here in the downtown core of the city I've lost signal @ 1800, went higher, got further...  height is related to distance kinda, direct line of sight means no interference, so if u find your losing signal try goin higher in the air, I have had success getting further this way. As for return mode I havent used it, but there are threads here with peeps talking about it

How far is too far is very relative. The aircraft will have no problem coming home and it doesn't care if your 5000ft or 15,000ft away. You just need to make sure you have the RTH altitude set correctly, have plenty of battery to make it back, know the winds and all the other variables.
Honestly, you say safest distance, that would be only a few thousand feet so you still have VLOS.

RTH is very reliable ... IF the operator understands how it works.
Every flyer should experiment with RTH to see what it does, how to activate it and how to cancel and resume control.
The time you need RTH is the worst time to start to learn about RTH.

Thank you everyone, GREAT to know!!

Of course we all follow the reg's and we only fly with line of sight; 2 miles is easily achieved with about 80% signal.  

But I have also lost signal at about 0.9 miles over water for more than a minute, using Litchi, which does not initiate RTH after signal loss!


I wish more users ask Litchi to give us an option to RTH upon signal loss during a mission.
(I am not sure if the current firmware allows it though, once a mission is uploaded in memory)

Without having such an option, it became a nerve wracking experience:

I had no signal, and I had no idea if the P4 was continuing it's mission?

My first thought was I was jammed because I was flying close to an area they do not like drones.

Was is down?

So RTH would not work of course since Litchi just continues the mission and I can not cancel the mission since I can not communicate with the P4!!
So any first time litchi users, think about this scenario before you upload missions.  I always try shorter missions first to "test the waters" before my final mission.

What if you cancel the mission, and then you regain signal for a few seconds, just enough to cancel the mission, and then the signal is lost again?  The P4 is a gonner in that scenario, assuming the low battery RTH does not work for you, or any manual attempt to RTH.

I was lucky, I let it run, then as soon as I had signal for a few seconds, I went to A mode, (in the future I will only use S mode for GPS tracking and faster speed) and I was able to bring it back.  Litchi has since added Home Lock, which make sit easier especially when there is glare on the screen, like in my case  I could only see the red nose pointing on the screen.
Side note:
We may see more jammers in the future, so it will be a great option for Litchi or any other mission software to allow us to go into RTH upon signal loss, set the RTH 300'-400' and thus avoid any danger.

I have safely flown out over water 5kms and then 5kms back.  I had 30% battery when I had returned.  It's all in the planning, I had line of site, enough altitude to ensure good signal and I was using the copper parabolic boosters.

You have to cancel the request to come home because of battery but be aware of your battery levels otherwise you will go swimming with your P4.

https://m.youtube.com/channel/UC5fJX6hRbbTmE9sHiwBANNg

lance.warren Posted at 2016-7-21 21:04
I have safely flown out over water 5kms and then 5kms back.  I had 30% battery when I had returned.  ...

I have to say it's a bit dangerous to fly long distance over water, because you won't know if there will be a sudden gust blowing against your drone when it's coming home, not to mention users often forget to observe the wind or forget that the wind in higher altitude can be much more powerful than that on the ground.
It's another story if you're flying over a river though, in case it doesn't have enough juice to come back, you can land it somewhere on the bank and retrieve it.

DJI-H.C Posted at 2016-7-22 15:16
I have to say it's a bit dangerous to fly long distance over water, because you won't know if there ...

Yeah I was a bit nervous but made it back ok.  Looking at the flight logs the flight was 4.5kms each way.

MD_Icarus Posted at 2016-7-21 19:45
Of course we all follow the reg's and we only fly with line of sight; 2 miles is easily achieved wit ...

Litchi does have a RTH if you lose the signal! Under settings then under aircraft then under "signal loss behaivior for manual flying" set that value to Return to home. I have had my P3P RTH using Litchi after signal loss.

mjlstudios Posted at 2016-7-22 08:35
Litchi does have a RTH if you lose the signal! Under settings then under aircraft then under "sign ...

But that RTH is only when you are flying in manual mode.  It does not initiate when you fly a mission.  There is no option to RTH during a mission.

In my scenario, when I lost signal, I could not initiate RTH of course! I did not want the P4 to keep going away from me when the signal was lost. I was lucky it made a loop and I recovered the signal and thus I stopped the mission, and then I could bring it back.  During the mission, you can only pause it, or stop it.  

They told me that this is a firmware limitation, when the flight is uploaded in the P4. I am hoping they work with DJI to add this option. It will only initiate RTH if it's far out and the battery life limitation kicks in; this is part of the firmware, not Litchi.  Unless they did some update recently?  I still use the version from 2 weeks ago.

lance.warren Posted at 2016-7-21 21:04
I have safely flown out over water 5kms and then 5kms back.  I had 30% battery when I had returned.  ...

I am curious to know what was your battery low setting? Did it initiate at exactly that preset level, or at some higher level, based upon the calculation the P4 does for coming back home with enough battery capacity.

I just updated to the latest Litchi version, but it still shows RTH for manual flying only.

MD_Icarus Posted at 2016-7-22 21:49
I am curious to know what was your battery low setting? Did it initiate at exactly that preset leve ...

It initiated low battery about 3.5kms into flight but I knew I had enough battery to continue and come home so I cancelled the return home and kept flying.

As said previously on this thread,practice with rth before you need it. One thing I have noticed is after a firmware update you need to make sure you rth altitude is correct. Mine always goes back to factory default.

MD_Icarus Posted at 2016-7-22 09:40
But that RTH is only when you are flying in manual mode.  It does not initiate when you fly a missi ...

When using Litghi and you loose the signal while in a mission, Litchi will complete the mission and then either hover or RTH which ever you selected in settings. You can also cancel the mission at ant time by flipping the mode switch from F to P and then RTH.

I was flying 3000 ft away quite a bit last few days with no problems at all, not a glitch !  So strange as I could even fly more than 300ft the two days before without the picture signal going green then black, all I done was a compass imu away from home in a field and also turned off geo been perfect since

I have flown multiple successful round trips with P4 out to 20,000+ feet max. distance at the turnaround point with very little loss in HD Link or RC control signal using only an inexpensive aluminum parabolic reflector slid over the two antenna.  

As other posters have noted, IF you plan to fly long distances, make sure you observe wind speed and direction. I strongly recommend flying long distances only on calm wind days or, if there is a wind, fly into prevailing winds on outbound flight and turn around at 60+% battery, so you will have a tailwind and plenty of battery to get all the way home. I also highly recommend attempting long distance flights only over unpopulated, open, rural farm and pasture land, and plan a route that provides numerous options for safe emergency landing spots on the return flight, if that becomes necessary.

You will need to change your body position and RC position continuously to keep the upright RC antenna facing your aircraft at all times. Select an interference-free manual HD channel selection ( I use Channel 20 95% of time) and the lowest video transmission speed (4 mbps) to ensure glitch-free live video viewing.  Both these options appear on the HD page of the DJI GO app. Do NOT use a screen recorder app (e.g., SHOU) or have any other CPU-instensive apps running in the background of your tablet. Best to clear all running apps from background and only run DJI GO app. Also, very important, ensure that there be a clear signal line of sight between your RC and aircraft at all times. For example, a 100-foot-tall tree 100 yards away can block your signal when your P4 is 3+ kilometers out on the other side of that tree.

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MD_Icarus Posted at 2016-7-22 09:52
I just updated to the latest Litchi version, but it still shows RTH for manual flying only.

listen here boy, in litchi app when you plan a mission it will tell you, distance it will take , time it will take if you plan a long mission fly  once it start the mission, it will go on its own, meaning if you want it to return to home you have to be in range to activate it on the controll just switch to atti and gps mode again, and then press return to home button in the controller, if its far away it wont do your command, just wwait till the drone flies the path YOU created , if you are smart enough the last waypoint must be near you ( SO YEA IT WILL COME HOME)

Have had my P4 for a week and just took my 8th flight.  Am flying in P mode so does not fly to fast.  Today I went 12,700 feet away and the battery level told me it was time to RTH.  I was flying between 300 and 400 feet altitude.  Did get a number of weak remote control signals but video never cut out and it kept moving forward.  

My final waypoint is always at the same point as waypoint1.

The main point I was making was that when the video and RC communiation with P4 are lost, and you have no video and Disconnected flashing on the screen for more than 1 minute, and the distance is less than half of what you have flown before, then your first thought is P4 failure or being jammed. If the firmware allows, what is wrong if we are given the option to RTH as soon as the RC signal is lost [size=14.5455px]for some defined time, when flying a Litchi mission.  I do not want the P4 to fly further, once I lose signal in some areas.

I also noticed, the last Litchi version has reduced the number of video channels now to match the dji-go app. They used to have higher channel hack, but that seems to have gone now.  But it only uses one channel for the entire mission so we have to guess which one to pick for the entire mission.  The Auto (frequency hop) setting is not really working.

MD_Icarus Posted at 2016-7-23 22:47
My final waypoint is always at the same point as waypoint1.

The main point I was making was that wh ...

good, i understand your point but the point of using litchi app is to make missions(paths) that make the drone follow automatly, if you dont want the drone to keep flying foward after you lose signal, just fly it manually , do not use waypoints mode.

people use waypoints to make videos of long distances framing certain point, so they just save it in the phone, turn on  the drone upload it to it, and up it goes alone. its amzing i dont think litchi app will make a RTH button while in waypoints mode, its useless if you ask me. think about it

egconstruger@gm Posted at 2016-7-23 23:35
good, i understand your point but the point of using litchi app is to make missions(paths) that ma ...

There is talk about jammers being used in some areas soon. It would be a nice option to be able to choose RTH in some missions when signal is lost.
I could then set the RTH height to 300' - 400' and let the P4 get lost up in the sky.

Is anyone else having the Video channel issue, when litchi does not stay in auto mode; the logs always show a single channel.  And in the latest version, the number of channels now have been reduced?