Hey all im always reading from this and the phantompilots forums and see  alot of horror stories that i hope i never go through. well it finally  happened to me. im from the chicago area, northside not too far from the  lakeshore. been flying since dec with a p4p. Have 389 flight and 49  hours flying, only had a small crash in my backyard into tree branches  the first month i had it , Had a few close calls with the lake,  headwinds, and battery but around here the lake is almost the only place  i can fly without worrying too much. Anyways last week monday sep 25 a  day after my bday i went out to lakshore drive right where downtown  starts to fly along the shore and get some evening shots around 830. the  sun had set about an hour or so before and there was still a little  light in the sky so i head out from a spot right along the shore and  lakeshore drive where i will get signal going south towards navy pier.  Get some great video and shots as navy pier and our downtown light up at  night. Coming back no problems or warning except a large wind warning  which i get anytime i fly out. As soon as im about 1200 ft away heading  back on sport mode(within view as i saw the lights flashing a few dozen  feet before) i get no signal instanly out of nowhere. the go 4 app says  "no image available, return to home?"  and i press okay but the rc light  was already red. I wait and go get my marco polo locator out of the  drone case and turn it on because i couldnt see the drone anymore and i  knew it wasnt far but i never got a signal. thats when i got worried  because i always keep it charged and turn it on before every flight so i  kinda knew it had gone into the water. Contacted dji, uploaded flight  record and their response was the record ended without any sign of  abnormality and they offered a 30% off coupon for another p4p. Is there  anyting i can do to better my chaces of replacement? i made no  error(imo) that would lead to the p4p falling straight outta the sky.  didnt see any bird and aircraft around and i was very close to the  shoreline. considering renting a kayak or just swimming around to try  and find it lol.. wish they made a water proof marco polo tag...i would  know where to dive!

I know that dreaded feeling.



" i get no signal instanly out of nowhere. the go 4 app says  "no image available, return to home?"  and i press okay but the rc light  was already red."

Curious, do you recall what was the battery level at that point?

25% battery left. this is the link to the flgiht record. not sure if this is how i do it:   https://app.airdata.com/main?fli ... _id=GENERALOverview

Can you upload to: http://www.phantomhelp.com/LogViewer/upload/
We can see more information there...

sorry for you, but apparently it's a normal anomaly, several drones have already been lost in this way, there must be a sacred bug in dji-go or even in the drone because several times I had the warning aircraft disconnected while it was very close to less than 100 feet brave with your dings with the dji bracket

Blunted_one1 Posted at 2017-10-3 09:00
25% battery left. this is the link to the flgiht record. not sure if this is how i do it:   https://app.airdata.com/main?flight=ba26b9da527759d6bc4fc14ed39ab2d9&page_id=GENERALOverview

Def had enough juice for it to continue flying.

Olivier Vietti- Posted at 2017-10-3 09:38
sorry for you, but apparently it's a normal anomaly, several drones have already been lost in this way, there must be a sacred bug in dji-go or even in the drone because several times I had the warning aircraft disconnected while it was very close to less than 100 feet brave with your dings with the dji bracket

"apparently it's a normal anomaly, several drones have already been lost in this way, there must be a sacred bug in dji-go or even in the drone because several times I had the warning aircraft disconnected"

Sure seems that way. Had an auto-warning to land over water a couple of weeks when I clearly had enough battery power at 65%. Luckily I didn't panic and brought it over land.

http://www.phantomhelp.com/LogViewer/RXYMPGJQZ1OOBC7476FQ/
Will try to write them again.too big of a loss to just give up that quick. especially when i enjoyed using it and took good care of it

I'm starting to learn a little bit here on this stuff, so those with more experience will likely have better detail.
From what I'm seeing I think you ran out of battery power.
Why
First, you started with 71% battery level...there is literally dozens of threads that explain why you can't do that.  Simplest reason, it is very likely you did not actualy have 71% on that battery.  The manual clearly states to never takeoff with less than a full charge on your battery.
Second, using Sport mode is a huge drain on battery power.  Therefore, if you were dealing with a low batt and in sport mode it is likely your battery went critical and then shut down during flight.  Your batt cells were very close to the magic 3.3v limit where you will no longer have enough power to fly, you were only about .3v away at end log.  At one point you were only about .2v away, when in Sport mode.

It is either that or you accidently flew it in to the water, however, based on the altitude that does not appear to be the case.

I'd have to say you ran out of power, granted this is my limited experience and knowledge but that is what it looks like.

Battery indicator does appear to be a false reading. Look how long it was stuck at 25%. It did give a hint of too far out earlier.

Blunted_one1 Posted at 2017-10-3 10:12
http://www.phantomhelp.com/LogViewer/RXYMPGJQZ1OOBC7476FQ/
Will try to write them again.too big of a loss to just give up that quick. especially when i enjoyed using it and took good care of it

Although the battery was getting low on voltage and Genghis9 has a good point, we should have seen it go into a critical landing if it was a battery issue.

As DJI say, there is no sign of a reason for the disappearance and without evidence you wont be able to claim warrantee replacement, their offer of a discount is decent.

If you can find the aircraft then the on-board log may explain what happened but unless the water is clear and shallow that seems unlikely.  From Google it does look like it may be shallow enough to see the bottom?  And there shouldn't be much water current there...

The only thing I see wrong is that the VPS Altitude is misreading occasionally, that would worry me but I don't see any reason a bad height from the ultrasonic sensors would have caused the disappearance.

I just wonder if you didn't start off with a fully charged battery like was mentioned, if with the high wind speed you were working the aircraft pretty hard. Seems strange that you didn't get the critical warning, but wonder if it had a quick voltage drop in a particular cell or something and the aircraft just shut-off?

Blunted_one1 Posted at 2017-10-3 10:12
http://www.phantomhelp.com/LogViewer/RXYMPGJQZ1OOBC7476FQ/
Will try to write them again.too big of a loss to just give up that quick. especially when i enjoyed using it and took good care of it

While we can pick little things out of your log, reality is it doesn’t show much that will help you, I also don’t think it shows enough to help dji.
I’m amused when they look at logs and they show no pilot error, they seem to have no problem putting the onus on the pilot, if they cannot prove pilot error and log cannot prove malfunction then in my book that is clearly 50/50 , and the fact that OP is obviously a good and loyal customer has purchased many of dji’s products, I think it’s p#ss poor they decide to lump 70% of the blame on the Customer and 30% on the product.
The Customer is always right is not operating here from what I can see.

ALABAMA Posted at 2017-10-3 11:16
Battery indicator does appear to be a false reading. Look how long it was stuck at 25%. It did give a hint of too far out earlier.

18 seconds on 25% not that long..

Someone explain how he could go out over 4000 ft with 70% starting charge and return.    It ran out of of juice, plain and simple.

hallmark007 Posted at 2017-10-3 12:04
While we can pick little things out of your log, reality is it doesn’t show much that will help you, I also don’t think it shows enough to help dji.
I’m amused when they look at logs and they show no pilot error, they seem to have no problem putting the onus on the pilot, if they cannot prove pilot error and log cannot prove malfunction then in my book that is clearly 50/50 , and the fact that OP is obviously a good and loyal customer has purchased many of dji’s products, I think it’s p#ss poor they decide to lump 70% of the blame on the Customer and 30% on the product.
The Customer is always right is not operating here from what I can see.

Good point, maybe 50/50 would be more reasonable but then if it had happened in the first week DJI would have paid 100% and this one is approaching 1 year old, some of it including the battery is out of warrantee.  Also the reason for the lack of evidence is that it is lost in the water, when you fly over water it is you the pilot taking the risk of loss and while you might expect DJI to pay for repairs after a malfunction it is not so reasonable to expect them to pay for replacement when it wasn't them that took the risk of flying over water.  Water damage is specifically excluded from the warrantee.

Nigel_ Posted at 2017-10-3 11:27
Although the battery was getting low on voltage and Genghis9 has a good point, we should have seen it go into a critical landing if it was a battery issue.

As DJI say, there is no sign of a reason for the disappearance and without evidence you wont be able to claim warrantee replacement, their offer of a discount is decent.

VPS is definitely off on a number of occasions, I wonder was it very foggy because I know from using spark in foggy weather it was continually getting readings when 80 metres in the air.

Nigel_ Posted at 2017-10-3 12:21
Good point, maybe 50/50 would be more reasonable but then if it had happened in the first week DJI would have paid 100% and this one is approaching 1 year old, some of it including the battery is out of warrantee.  Also the reason for the lack of evidence is that it is lost in the water, when you fly over water it is you the pilot taking the risk of loss and while you might expect DJI to pay for repairs after a malfunction it is not so reasonable to expect them to pay for replacement when it wasn't them that took the risk of flying over water.  Water damage is specifically excluded from the warrantee.

I understand Nigel and everything you say is true, but it also brings into question dji’s promotions of users quality videos and photographs which they continually use and encourage users to post such material and gladly except the great free promotional although inadvertently good publicity it brings them, they never refuse to or try to discourage the great results and the wonderful footage produced by their customers using their aircraft, you can’t have it both ways, it would also be nice to think they appreciate customers who support their products again and again.
But yes I see where they are coming from.

We've seen this before when hauling home in ATTI and low battery (ATTI = Sport Mode).  The risk is one of the cells will hit the magic 3.0 volts and the battery will shut off without warning.  That's my guess.  Sorry for your loss.  

I think there is a bug because I had the very similar experience when flying in sport mode and also have seen other users having the similar issues in sport mode. I suppose this can't be considered as pilot error because there seemed to be enough battery for RTH. There is no evidence it was a pilot error and thus this should be covered by warranty no matter the fact it fell down to water. If the data from battery was wrong it's the problem of DJI and its product. One would have to fly just over the backyard to be sure to find the bird after the crash which is against common sense.

Launching with 71% battery is pilot error.  

Mark The Droner Posted at 2017-10-3 13:17
Launching with 71% battery is pilot error.

For sure.  And how long did it sit idle between this flight and the last charge.  So many pilots think that they can place a charge maybe once a week and fly till battery says 20%.  It doesn't happen.

Blunted_one1 Posted at 2017-10-3 10:12
http://www.phantomhelp.com/LogViewer/RXYMPGJQZ1OOBC7476FQ/
Will try to write them again.too big of a loss to just give up that quick. especially when i enjoyed using it and took good care of it

Did you have a gimbal guard fitted ? Seems unusual to get VPS readings at that height.

Blunted_one1 Posted at 2017-10-3 10:12
http://www.phantomhelp.com/LogViewer/RXYMPGJQZ1OOBC7476FQ/
Will try to write them again.too big of a loss to just give up that quick. especially when i enjoyed using it and took good care of it

Sorry about your loss, it is difficult, but I think you just pushed the aircraft beyond its expected limitations.

If it's assumed for the sake of argument that the battery percentages in this case are an accurate indication of battery charge. Then the aircraft had used 39% of the 70% charge to get to maximum distance, that left 31%-10 % = 21% to get back home over the same distance before the critical battery landing came into play (the 10%).

One other thing that is never mentioned, or at least rarely, was the battery firmware up to date ?

Mark The Droner Posted at 2017-10-3 12:50
We've seen this before when hauling home in ATTI and low battery (ATTI = Sport Mode).  The risk is one of the cells will hit the magic 3.0 volts and the battery will shut off without warning.  That's my guess.  Sorry for your loss.

Those are exactly my thought too Mark. Makes you wonder if it just briefly went below that threshold and BAM!....shutdown. I have seen it happen.

Thanks everyone fore your insights and opinions .Yes i used the aircraft 2 days before  for a few mins and didnt expect to take too long on this flight so i didnt switch out the battery( i have 2 others) for a fresh one. Ill always wonder if thats what did it.i suspected the battery giving out but didnt realize flying with it at that level could do that. Even the sport mode using too much juice at the end sounds possible but like i said in my post i almost always fly near the lake over the shores and water many many times as this is the only place i could get signal at a distance and fly this freely this close to home. I used the sport mode in low battery levels many times as well to get the ac back to me quicker if it was fighting a headwind or it started raining or something. Ill never know but ill let u know if dji updates me with a better offer.i have accessories and dji goggles that i used with it. was planning on a mavic when i had the chance...

Sportbike_Pilot Posted at 2017-10-3 10:00
"apparently it's a normal anomaly, several drones have already been lost in this way, there must be a sacred bug in dji-go or even in the drone because several times I had the warning aircraft disconnected"

Sure seems that way. Had an auto-warning to land over water a couple of weeks when I clearly had enough battery power at 65%. Luckily I didn't panic and brought it over land.

it makes a drone a week that is lost in these circumstances, it's a lot for this silk of the hazzard, and it is that what is announced on this forum, in my area there are more than 5 drones all models confused lost in the last three months ...

I'm sorry to read your post. Could you tell us your case number? I'd like to look into the exact status.

It may have tried to land itself in the water, just before you lost signal you had this warning message "Attitude too Large. Exit Backward Obstacle Sensing." Seems you drone was under the impression that there was an obstacle in front of your drone.

Mark The Droner Posted at 2017-10-3 13:17
Launching with 71% battery is pilot error.

I don't understand why launching with 71% battery would be a pilot error. If I launch with 100% I can fly +- 20 minutes, with 71% I can fly +- 14minutes. If the battery reports wrong status it is a problem if the battery and not the pilot. When I see battery is at  50% l suppose it is at 50% and not 3%. If the battery can't report the correct data it should be fixed in firmware and the bird could refuse to land off with the battery in a such condition.

shamot Posted at 2017-10-4 07:02
I don't understand why launching with 71% battery would be a pilot error. If I launch with 100% I can fly +- 20 minutes, with 71% I can fly +- 14minutes. If the battery reports wrong status it is a problem if the battery and not the pilot. When I see battery is at  50% l suppose it is at 50% and not 3%. If the battery can't report the correct data it should be fixed in firmware and the bird could refuse to land off with the battery in a such condition.

Well you may think and believe what you prefer.  However, as stated many times and in many places here in the forum it has been more than proven and explained that these batteries after being drained down from full/100% and then stored and then used that their stated "percentage" will not match the voltage available.
Now I'm no electrical engineer, but it is clear about this one element to the battery design and it is also why DJI tells you to only use a fully charged battery for each flight.
If you want some serious detail on this subject read this thread in total: https://forum.dji.com/thread-41951-1-1.html
...and then read this in total: https://forum.dji.com/thread-51147-1-1.html
If you still don't understand then I suggest you contact DJI tech support or take up researching electrical engineering or find yourself an expert that can explain it for you.

Yes.  And if that isn't enough, the P4 Battery Safety Guidelines clearly states on page 3:  Make sure the batteries are full charged before each flight.

Mark The Droner Posted at 2017-10-4 10:05
Yes.  And if that isn't enough, the P4 Battery Safety Guidelines clearly states on page 3:  Make sure the batteries are full charged before each flight.

Can't emphasize enough, for 50% of the cost of a battery you can insure your drone against any loss for full replacement cost with State Farm under "Personal Article Property" for a year,  takes away the worry and replace your drone at Best Buy within a week!! I do not fly any of my DJI products without it.

QuadKid Posted at 2017-10-4 11:56
Can't emphasize enough, for 50% of the cost of a battery you can insure your drone against any loss for full replacement cost with State Farm under "Personal Article Property" for a year,  takes away the worry and replace your drone at Best Buy within a week!! I do not fly any of my DJI products without it.

Like a Good Neighbor...

shamot Posted at 2017-10-4 07:02
I don't understand why launching with 71% battery would be a pilot error. If I launch with 100% I can fly +- 20 minutes, with 71% I can fly +- 14minutes. If the battery reports wrong status it is a problem if the battery and not the pilot. When I see battery is at  50% l suppose it is at 50% and not 3%. If the battery can't report the correct data it should be fixed in firmware and the bird could refuse to land off with the battery in a such condition.

Because 71% indicated is not 71% if you are using a battery that's been lying around and is partially discharged.
If you looked at the voltage the battery delivers, you'd find that it drops quite quickly and gets to the critical 3.3V much earlier than you would expect.

i even purchased an expensive 250 third party full coverage warranty but missed the insurance. And 30% percent is all they could offer. to any DJI representatives:can the 30 percent be used on another item besides the P4P? i dont think i can afford another P4P(excludes controller but still pricey) until next spring but would like to get back in the air with a mavic pro and with the coupon it may be possible.my case number is CAS-1041378-J6N1J7

Thanks again for all the replys. Its nice to see alot of people coming together for this cool interest. i got very much into the drone life since last thanksgiving when i came across some drone videos and they had kinda flown under my radar until that point so i had one by end of dec. By the way i ended up finding a like new nvidia k1 tablet in the beginning of summer and i have to say once i rolled back to the previous firmware on the tablet its been pretty much perfect  as an android tablet for dji go 4 in case ppl are still having problems with that. hard to find but worth it. And i wont be flying with anything than a fully charged batt from now on