Hi, just wanted to share what happened today to see if someone can help me explain what happened with my quad today - have been looking for it for 5h with no success.

- PV2+ v3, bought around 2 weeks ago
- Around 25 successful flights (another 30+ in a phantom 1 previously)
- Compass calibrated before flight, battery 100% charged, home point stored and 12 satellites
- Phantom in GPS mode, no Naza activation
- Flying at around 100m (328ft) height, 800m (2500ft) distance over a valley 200m deep (650ft)
- at the bottom of the valley, power lines (250m  below the drone)
- fpv booster installed (5 successful flights before)

Recording a video over the valley with perfect reception, suddenly the phantom starts accelerating at full speed away from me, until it reaches c.1050m (3350ft) distance, then turns upside down a couple of times and then stabilizes. I turn off the controller to activate come home and it starts coming towards me. When at 900m distance (2800ft) and 65% battery I turn off come home to bring it back manually and all connections break down. Never came back to home point, came back to my viewing or hearing range.

I understand this was not due to wind but from a failure of the systems of the phantom, but could have this been caused by the powerlines 250m below? From what I understand max distance for electromagnetic influence is 50m and I had flown very near those (150m or 400ft) 2 days ago.
Could it just be a sudden failure of the gps/compass due to the low quality components in the phantom?
Could it be the FPV booster?

It would also be helpful to understand the likely behaviour of the phantom after the connections broke in order to try and find it, free fall or return to home? (I stayed waiting for 25min and nothing happenend in my vision app)

Thanks a lot

I've never used the FPV booster and don't think it's directly responsible except in one way - it enticed you to fly further away than you might have normally and that pretty much guarantees you are going to lose your quad sooner or later.

It's difficult to pin down exactly what happened in many cases like this. Normally, those lines should have been fine. But we don't know how powerful they are!  I think, lines or not, you were at the far end of range of the Phantom. Remember, any times given by DJI are maximum and it would not be a bad idea to cut them by 30% or more in your daily flying.

My guess is that you would have had much more luck if you had been in NAZA mode and had practiced recovery a couple times using home lock and/or atti flying.  GPS, for whatever reason, is not very reliable...
As far as a total guess - my thinking is the combination of a better GPS antenna or shielding (some aftermarket companies offer this) and NAZAM mode may have allowed you to get your craft back.

May I ask why you never activated IOC mode?

droneflyers.com Posted at 2014-12-27 05:56
I've never used the FPV booster and don't think it's directly responsible except in one way - it ent ...

Power lines were very powerful I believe 400kV according to a map I downloaded, but still 250m away, can someone clarify if this could be the cause?

Re IOC mode, I had never used it in the past, I fly to take pictures and video and never activated IOC, Home lock or any of those modes.

CME = Solar activity very strong today....

You said you " I turn off come home to bring it back manually and all connections break down" I think it maybe do to going back to manually, I would have let it come back to home point. It could be because it lost the home point. I know some that did something like what you did, and in went into the ocean. His was coming back to the beach and he went in to manual mode some how, and it just dropped into the water.

Now, please understand, this may not be the reason you had your issue, but it was his., also did you , and please understand I am just asking, but did you check the "Find My Phantom" in the app.

skymaker6@gmail Posted at 2014-12-27 06:21
You said you " I turn off come home to bring it back manually and all connections break down" I thin ...

Yes, I used the find my phantom with no success.
What did the drone do in your friends case? Didnt it hover steadily waiting for manual input or just fell down? Why did I lose the fpv signal then?

I am starting to think it may be the power lines

mixstreme Posted at 2014-12-27 06:21
CME = Solar activity very strong today....

It was a two on an app that I use as well as another website.

Paras Posted at 2014-12-27 06:33
Yes, I used the find my phantom with no success.
What did the drone do in your friends case? Didnt ...

I'm sorry you lost your Phantom. I hope you'll find it.

I understand you took off with 12 satellites coverage - but do you know how many satellites coverage you had when you Phantom started the flyaway?
It could be a combination of electromagnetic interference (solar storm + power lines) doubled by a software issue in the Phantom software when there are errors with GPS reception. I've experienced 2 flyaways today, but I was able to recover by going in ATTI mode (NAZA mode was activated in my case).

In theory, with good GPS coverage, your Phantom should hover in one place until it's low on battery and then land wherever it is. Your problem is that your Phantom went crazy (executed a straight flyaway) - and if it goes straight in one direction that makes it way more difficult to find. Do you remember the direction it took on the first flyaway?
Maybe you ended up with a second flyaway And draw a line from the last know position of your Phantom in direction of your first flyaway. My experience today was that my both flyaways were in the exact same direction (south).

ciprianboboc@gm Posted at 2014-12-27 07:11
I'm sorry you lost your Phantom. I hope you'll find it.

I understand you took off with 12 satelli ...

Many thanks, really hope to find it
I will try to search in a 500m radius from the find my pphantom point (last gps coordinates sent before losing connection, I understand)

Do you know if with better quality components these flyaways could be avoided? I will only buy another drone if these issues become less common.

Paras Posted at 2014-12-27 07:32
I will try to search in a 500m radius from the find my pphantom point (last gps coordinates sent b ...

I'm not experienced enough to answer your question, but, in my opinion, the components are pretty good. Maybe they should've installed a better GPS receiver or a sensor to work with Glonass, too.
I think the problems are mainly due to software bugs in GPS mode - they want to do too much on user's behalf. From what I've read and experienced, ATTI flight mode is quite reliable and a good safety net in case that GPS mode acts crazy.

Paras Posted at 2014-12-27 06:33
Yes, I used the find my phantom with no success.
What did the drone do in your friends case? Didnt ...

He said that switch it to manual and then it just stop and drop.

Hi Paras, when you said you try to bring it back manually,  did you switch to manual mode? Or just terminated the auto return, and manually flew in the original mode you were operating? I assume you proceed the regain control sequence. if so, did you have the control or it went straight flying to a certain direction?

DJI-JS Posted at 2014-12-27 08:01
Hi Paras, when you said you try to bring it back manually,  did you switch to manual mode? Or just t ...

I was hovering in manual mode to record video and the phantom was stable, suddenly, connection was lost for 1 second and when image came back the phantom was flying away at full speed. It then turned upside down a couple of times and regained stability. Then it turned on return home mode. When I switched it back to normal gps mode and pushed the right stick upwards to bring it home quicker connection was broken - never came back.
What do you think is the reason for the phantom acting crazy?

Paras Posted at 2014-12-27 09:07
I was hovering in manual mode to record video and the phantom was stable, suddenly, connection was  ...

Paras, do you really mean "manual mode" or "ATTI mode"? Was your S1 switch in the middle or low position?

power line are the issue, when ur remote sent signal it was distorted by power lines, also gps might be effected by it...unless you fly manual mode

jarek33@hotmail Posted at 2014-12-27 12:43
power line are the issue, when ur remote sent signal it was distorted by power lines, also gps might ...

IMHO, that depends on what you mean by "power lines". If we're talking high-voltage long-distance transmission lines carrying 100kV or more, then you might find an EMF going out 200 feet or more. Likely wouldn't mess with your radio, assuming tht DJI uses even a minimal amount of filtering and a reasonable-quality receiver, but it might affect other electronic features like GPS or compass. Lesser distribution  lines....likely not a problem unless you happen to be flying withing about 25 feet of an old tranformer that might be leaking RF. I realize that it runs counter to the mantra on these internet forums, but given the wide variety of consumer-grade electronics in these $1000 consumer drones and the relative sophistication it takes to control their various features, I suspect that interference from power lines is pretty far down the scale of things that bring these things down.

My drone crashed...must be the power lines in the next county....Hmmmm

I don't think power lines are as much of an issue as people make them out to be.  I flew over a power generating station and the numerous 300 kv lines about 60 feet above them with no problem.

Gerry1124 Posted at 2014-12-27 13:40
I don't think power lines are as much of an issue as people make them out to be.  I flew over a powe ...

Can you try to do the same flight under neith the power lines ? I did fly mine and I lost control of my drone, I quickly switched to manual mode and regain control, seamed like gps totally lost it and went crazy

jarek33@hotmail Posted at 2014-12-27 22:13
Can you try to do the same flight under neith the power lines ? I did fly mine and I lost control  ...

If you want to take a chance with being reckless, that is your choice.  If you are under them and lose signal, what would happen?  You would revert to RTH and where do they go when they revert to RTH?  They go straight up into the wires.  I would not want to pay for damages of shorting out the north country or being held responsible for blowing out transformers.  I don't go under trees or power wires.

Gerry1124 Posted at 2014-12-27 23:11
If you want to take a chance with being reckless, that is your choice.  If you are under them and  ...

well then don't say power lines have nothing to do with it, gps signal was lost in my case, and second it won't go up when u loose gps signal, don't lie here, when u don't have gps how will it know what altitude to climb or even where is at, phantoms are not equipped with mode c and altimeter settings, when you response don't try to be smart here, simple don't fly near power lines, and you go ahead and say oh no its totally fine, well its not...you rookie

jarek33@hotmail Posted at 2014-12-28 00:07
well then don't say power lines have nothing to do with it, gps signal was lost in my case, and se ...

Rookie?  More than 75 flights so far on 2 Phantoms, and not a problem on either.  I don't fly carelessly.  I'm not the one having problems here, you are.  Enough said.  Good luck trying to figure out your problems.

Just pop my head up and say that GPS has nothing to do with altitude control on the Phantom, it uses a barometric sensor calibrated to zero at the take-off point.
If you lose control it will go into RTH or Failsafe with no GPS it will auto-land where it is and not climb at all. If it has GPS then it will climb to the set altitude and return to home. (if already above the set altitude it will come home at that height).

I'd say the same thing as power companies claim - that is, that power lines do not affect GPS in other than the most extreme conditions - especially directly underneath them where they are between the satellites and the quad.

I'd also agree that power lines get blamed more than they probably need to be. GPS problems on certain Phantoms may be due more to interference from the camera, gimbal, etc. or solar storms...or just bad GPS reception in general.

droneflyers.com Posted at 2014-12-28 03:04
I'd say the same thing as power companies claim - that is, that power lines do not affect GPS in oth ...

I agree that power lines do not affect GPS readings too much.
You can do a simple test, not involving a Phantom. Take a smartphone under high voltage power lines or next to a transformer station and see how much impact it's there on your phone's readings. The phone software is also performing some corrections, but nevertheless, you can try this test.
Meanwhile, try the same test for compass readings. I've never done any of this test, but I'm pretty sure there will be some influence on compass.

Powerlines

jarek33@hotmail Posted at 2014-12-28 00:07
well then don't say power lines have nothing to do with it, gps signal was lost in my case, and se ...

Flying around power lines is not a big deal. It's not the boogeyman you think it is. There are many, many reasons you might lose a GPS slgnal. Proximity to power lines is way down the list.

And by the way...altitude is determined by barometric pressure, not GPS.

Where was it lost?

Keeping away from high voltage power lines is number 3 on the flight requirements list in the manual. I guess DJI put it in there for a reason.

As someone who's been working with GPS since 1980, I can assure you that you won't lose lock due to power lines. The footprint, or shadow is not large enough to affect it. Even if you sat under one, the most that would be blocked is one sat.

johnwarr@live.c Posted at 2014-12-28 02:31
Just pop my head up and say that GPS has nothing to do with altitude control on the Phantom, it uses ...

That's the only thing that phantom uses for altitude, u need at least 5 for altitude

jarek33@hotmail Posted at 2014-12-28 07:08
That's the only thing that phantom uses for altitude, u need at least 5 for altitude

Barometric pressure sensors. Like an altimeter. Not GPS.

Just checked with an electric engineer and he told me that at 200m the influence of the power lines is negligible, it could have affected the compass if the compass is low quality but nothing major.

My phantom ran away, flipped a couple of times upside down and lost contact with controller and iphone and never came back home.

Right Paras, I've flown over 300 kv lines within 50 feet and wires on the road with transformers on the poles within 20 feet with no problems many times.

Paras Posted at 2014-12-27 09:07
I was hovering in manual mode to record video and the phantom was stable, suddenly, connection was  ...

Hi Paras,
according to the detail you provided, it will be less likely that the GPS signal got interference, but most likely the RF signal and compass had some issue. Because the return to home was working, so the GPS was working fine. The only change after that is the Tx was turned on and regained control. if the RF signal got interfered by some source, power line as an example, it could result abnormal behaving.

Sorry for your lost.

DJI-JS Posted at 2014-12-30 01:46
Hi Paras,
according to the detail you provided, it will be less likely that the GPS signal got int ...

What would have been the behaviour of the phantom after connections broke down?
I kept the remote on

Hi Paras,
I am confused. In your original post, you mentioned:

Recording a video over the valley with perfect reception, suddenly the phantom starts accelerating at full speed away from me, until it reaches c.1050m (3350ft) distance, then turns upside down a couple of times and then stabilizes. I turn off the controller to activate come home and it starts coming towards me. When at 900m distance (2800ft) and 65% battery I turn off come home to bring it back manually and all connections break down. Never came back to home point, came back to my viewing or hearing range.

But now you said you kept your remote on.

If the connection is broke, the phantom will enter the fail safe mode, and commencing return to home process. During this process, if the S1 switch is at the top position (GPS mode), the control will be regain after reconnect AND S1 switch is moved. If S1 was at other position (manual or ATTI), the regain will be immediate after the phantom and TX connects again. And you mentioned you were not flying in GPS mode, so the control will be regain immediatly after the quad reconnected to the TX. So if you kept TX on all the time, there could be a short time period that the signal from TX was intermittent, and that could ruin the return to home process.

Usually when return to home is actived, turn off the TX is a good idea. And turn it back on when you sure the connection will be solid.

When at 900m distance (2800ft) and 65% battery I turn off come home to bring it back manually and all connections break down

After this connections went off I didnt turn the remote back off again

Paras Posted at 2014-12-30 04:04
When at 900m distance (2800ft) and 65% battery I turn off come home to bring it back manually and al ...

You did not activate NAZA mode? Your quad was in phantom mode right?

Manual mode is not available in phantom mode. How did you cancel rth? Did you turn the transmitter back on and flip s1 down and up?

Possibly related: On my last flight a few days ago with 3.10 software, I was testing the NAZA mode. NAZA is great for newbies despite what the docs say. I noticed that when I used the return to home feature while in home lock mode, when I flipped off return to home, home lock appeared to be disabled and the controller acted like it was in normal mode. Flipping the S2 up and back down again put it back into home lock mode. This happened twice while I was testing NAZA and return to home.

The reason this could be related is that the user switched on his controller again during return to home and then found that the P2V+ was uncontrollable. It is possible that the controller can get into a bad state when it is turned on and the P2V+ is in return to home mode.?