I have experience with RC planes, helicopters (T-Rex) and other drones.
During the last 2 months, I have used some smaller drones virtually without any crash (e.g. Syma x5)

I've purchased recently a Phantom Vision 2+ and had a few flights. The new drone and remote was updated to the new firmwares and calibrated accordingly. Before every flight I do a compass calibration.
But, I've experienced a fly-away today: http://youtu.be/yA1Pwc079QU (starting from 0:42 mark)
I'm puzzled about what happened. After I rotated the drone aprox 90 degrees to the left, it started drifting high speed to one direction (away from me). It also rotated by itself but maintaining its straight course away from me.
At 1:24 mark, the drone wanted to land itself in a tree... Eventually, it went up again to safety.

I suspect it was either interference or some bad GPS readings - and the drone may have miscalculated its home position or something.

When the drone was out of sight (behind a big tree), I eventually turned off the remote hoping for return to home.
Return to home did not kick in, and eventually after aprox 1-2 minutes, I was able to regain control, push it up, rotate it a bit to find its orientation and eventually land it safely.

Are there any logs for this drone to be analyzed?
What can I do more in order to avoid such fly away experience (except software calibration, compass calibration before the flight, wait for 6 GPS satellites, etc)?

Today was a high geomagnetic storm and i wonder if that may have caused what you see.

kenargo Posted at 2014-12-8 14:43
Today was a high geomagnetic storm and i wonder if that may have caused what you see.

I think you're right - the fly-away may have been caused by loss of GPS signal.

I remember that I've seen that the drone was not stable at landing (I tried to catch it with my hand and it drifted away because, probably, poor GPS reception at that time - the leds were yellow despite the fact that the sky was pretty clear and I was in a place where I usually have good GPS reception).

That makes me think... What do you recommend in case of GPS failure? Return to home probably is not going to work anymore and failsafe mode will create more problems than help - so I assume I should configure my remote to use ATTI mode and/or pay more attention to what's displayed in the Vision app on my phone?

Glad you got your bird home.
I am waiting for a response on another forum to prevent this type of fly away.
The question is: if you think GPS is not working properly, can we switch to ATTI and switch also to IOC(intelligent orientation control) that way you can pull back the right hand stick, and which ever orientation is it will fly directly to the home point.

Be careful with hard landing, land in grass or on windy day just reach up and grab it with right hand and stick down motor off with left hand, easy to do

"IOC(intelligent orientation control) that way you can pull back the right hand stick, and which ever orientation is it will fly directly to the home point."

In NAZA mode

gsp171@mchsi.co Posted at 2014-12-8 23:17
"IOC(intelligent orientation control) that way you can pull back the right hand stick, and which eve ...

Yes, that's exactly what I'm thinking: to enable other fly modes (ATTI and IOC) in NAZA software.
IOC was not enabled for me, but it sounds quite good in theory.

I wonder if my fly-away was caused by GPS or interference issue. I hope for GPS problems - at least those can be prevented by switching indeed to other flight modes... But interferences are quite scary - if we fly low (close to buildings or trees) - what can be done in case of interference? I'm afraid the answer is not too much and avoid to fly in those areas...

In NAZA mode, you can configure S2 down for total manual flight, (no GPS),,, and manual fight is pure manual control, NO hands off hover!

a buddy of mine had the exact same thing happen, while flying over houses.. we wondered if any wifi interferance from houses was the cause.

ie drop in locked sats causing flyaway.

Amazing how dependent we've become on GPS.

I've lost my yesterday? It happened exactly what you,I turned the camera 90 degrees and suddenly I lost control over it.I turned off the controller but it did not help,He still flew ahead and to the top.Unfortunately I was not found him I had it only 2 days This app find m,y phantom  is not helped, a place on the map is empty it was not there( can someone help me ) ? find , still I see that he is there on to the phone MAP BUT ITS THERE IS NO IN THIS PLACE

When doing a waypoint mission, if the Phantom lost GPS what would happen ?

umpa Posted at 2014-12-9 04:03
When doing a waypoint mission, if the Phantom lost GPS what would happen ?

Here is how RemE, a respected P2V+ pilot over on RCG, answered your question when another poster wondered the same thing...
1. What will happen if GPS signal would disappear/diminished during mission?
Good Question, My guess is that it would cancel the mission and hover, wait for your command, then autoland as it would not know where to go.
I can only guess as well because I've not lost GPS signal.
2. What will happen if control signal interrupted/lost during mission?
I believe it will complete the mission.
3. What will happen if booth wifi and 5.8 control are lost during mission?
Same as #2, I believe as it has the mission info on-board.
FWIW, I would have supplied the same answer, but figured it coming from two experienced waypoint pilots might mean more to you...

a.zajac5@wp.pl Posted at 2014-12-9 03:57
I've lost my yesterday? It happened exactly what you,I turned the camera 90 degrees and suddenly I l ...

Oh, that's horrible. I'm sorry.

I wonder if there's a bug in the latest firmware...
The lessons learned by me are to:
- avoid flying close to homes (where there's a higher chance of interference)
- check for geomagnetic activity (http://www.swpc.noaa.gov/rt_plots/kp_3d.html)
- check for GPS satellite availability (http://satpredictor.navcomtech.com/)
- use other modes (IOC or ATTI) when return to home / fly safe fails...

Do you have any other suggestions? I'm specifically interested what to do in case of interference. I understand we can set limits (how far and how high the drone can go)... but unfortunately those can not be set in the phone app itself (but only in the desktop software).

Concerning IOC...
Remember that Home Lock requires a GPS signal as well.
Course Lock is compass dependent and will work without a GPS signal.

The problem I face is that my missions usually take the drone out of my line of sight (which is why I use them) so atti would be of no use (i usually lose video too), if it ever failed I would be screwed.  fortunately  I don't fly over 'congested areas' so all it would do is land in a field - power line - lake - train line - jeez would be safer in someones back yard - lol

ciprianboboc@gm Posted at 2014-12-8 15:59
I think you're right - the fly-away may have been caused by loss of GPS signal.

I remember that I ...

When GPS  signal was poor ,  Phantom will  automatically switch to  atti mode(u must control Phantom manually ) from gps mode .And Usually , we set Course Lock before a long distance flight .

ciprianboboc@gm Posted at 2014-12-9 04:30
Oh, that's horrible. I'm sorry.

I wonder if there's a bug in the latest firmware...

When Phantom happen interference ,it seems totally out of control ,but sometimes you can switch S1 to atti mode and regain the control.

I've researched more this subject.
One suggestion is to enable dynamic home point - therefore the homepoint will be given by the position of the smartphone (which is pretty reliable for me). What do you think?

I've seen people complaining about the stock white transmitter... I've never experienced an interference with my old Spektrum 6 transmitter for a few years - and now I get a flyaway of my new P2V+ in a few days? I hope it was just a GPS issue (maybe due to a solar storm). I realize P2V+ has its own complexity, and all these "failsafe" features come at a cost.

I've watched my own video a few times to determine what could've happened. I know it was not user error (after 0:41 mark you can see the drone moving away from me and also rotating in flight, but keeping its direction - that would be a rather difficult if not impossible thing to do on error or purpose).
I was asking myself how I can prevent future issues like this (for me and others). I don't think there is an option in the default DJI Vision software to analyze the history of the flight (except the video capture). Because I have experience with iOS development (I have released 5 iOS apps in the last 2 years), I'm thinking about applying for DJI SDK dev program and maybe write an app to track all this data (at least GPS position, timestamps and extra flight telemetry). Of course, let me know if something like that already exists so you can save me some time and effort...

Even with a dynamic homepoint, if the Phantom loses 'position lock', it would not be able to navigate to it, as it would not know it's position relative to the homepoint.

umpa Posted at 2014-12-9 04:38
The problem I face is that my missions usually take the drone out of my line of sight (which is why  ...

To take advantage of Atti and Course Lock (CL) if you lose GPS and are BVR, you need to pay attention to where the aircraft is approximately located.
And, if you risk BVR (not exactly a good policy in light of the FAA's recent power play), you surely should know about where your craft is...
For example, if you flew out a mission to the front and left of you, in CL you would need to pull the stick back and to the right to attempt to regain sight of the craft.
In other words, reverse your flight path...

T J Gilbert Posted at 2014-12-9 04:25
Here is how RemE, a respected P2V+ pilot over on RCG, answered your question when another poster wo ...

I tested this scenario now with the props off, I brought it in side house to block GPS.  It hunts a minute then lands itself, more accurately it tried to.

Who lost, crashed, flyaway a Vision 2 + near the University of Delaware today December 9th around 10:15am

Saw your post on RCgroups, Jeff.   Apparently a clueless operator.  I can't imagine being a Phantom pilot and not checking these forums regularly.

umpa Posted at 2014-12-9 04:03
When doing a waypoint mission, if the Phantom lost GPS what would happen ?

Hello,my friend, answer as below:
1. What will happen if GPS signal would disappear/diminished during mission?
Answer:It woul cancel the mission,and stay for new command,and fly mode is ATTI mode until the GPS signal is recovered.

2. What will happen if control signal interrupted/lost during mission?
It will complete the mission because the mission had been saved in the MC.

3. What will happen if booth wifi and 5.8 control are lost during mission?
same as question 2

jeffstreavel@gm Posted at 2014-12-10 10:50
Who lost, crashed, flyaway a Vision 2 + near the University of Delaware today December 9th around 10 ...

dude, you are very kindly.but i don't think that the owner can notice your message.

maybe you can tell the school authority, the owner probably someday ask University staff for lost P2 V+.

Yeah - in atti mode its likely to drift away though yes ?

Im in the UK so FAA is not an issue for me, but the CAA have the same rules .   My distances are not that great, and I lose sight & signal because of trees & hedges.  Its not over a 'congested area' but is in a 'difficult area to get to'  which is worse for me lol.

For what its worth so far way point missions have been 100% successful and has performed much better than I thought it would.  When the flight takes much longer than I anticipated its always AH Twitch time, but always comes home.

umpa Posted at 2014-12-10 15:41
Yeah - in atti mode its likely to drift away though yes ?

Im in the UK so FAA is not an issue for m ...

I applied to DJI dev program and I was positively impressed with their very quick answer to my request. I've looked at their SDK and a lot of useful info is exposed in DJIGroundStationFlyingInfo class (home base location, drone location, drone speed, satellite count, control mode, etc).
Now I hope I get the spare time to write a free iOS app to log / display all that useful info for post-flight analysis.

I'm still not sure what caused my flyaway on Sunday. I had other flights since then (and no incidents) - some of them in the same neighborhood. I hope it was a GPS glitch - home position set incorrectly + weak signal from my transmitter causing a "return to home" (but at a wrong "home" location).
Since then, I've enabled ATTI mode and Course Lock on my remote, so in case of another flyaway I'll try to switch to ATTI. I'm not yet quite confident with Course Lock as long as it depends on quite good GPS reception (and bad GPS reception could've been the cause for my flyaway).

On my location, GPS is not always reliable (sometimes I get 7 satellites, other times I get only 4 or 5).

The drone seems to take well some wind and it seems quite stable in ATTI mode. Yes, it's not going to perform a perfect hover by itself in ATTI as it does in failsafe GPS mode (it slides slightly because inertia or wind - but quite manageable).
I'm also paying more attention to their bottom-left position indicator in the vision app - it seems that that indicator (especially if tapped) can be quite useful for trying to regain control and especially orientation in case of a flyaway beyond the line of sight...

Now I may be wrong here - but my understanding is that GPS is required for Home Lock, not Course Lock. So no GPS no come home anyway. Perhaps some one in the know could pipe in and advise.

umpa Posted at 2014-12-11 02:22
Now I may be wrong here - but my understanding is that GPS is required for Home Lock, not Course Loc ...

Home lock would require a GPS fix as to where the Phantom is but course lock relies on magnetic fix from take off point and will come back to home point by pulling back on the right stick.  

how can you find a phantom 2 vision + if the battery is gone for 4 days in looking for it everyday 6hours everyday

DJI-szz Posted at 2014-12-10 14:43
Hello,my friend, answer as below:
1. What will happen if GPS signal would disappear/diminished dur ...

For your answer to Question 1, does it mean that if it gain GPS, it will follow back the mission and if the battery is low is will RTH ?

Once you go into RTH mode, it will cancel the waypoints and stay in RTH mode until you regain control if you are within range, but it will not finish the waypoints.

Gerry1124 Posted at 2014-12-11 04:11
Once you go into RTH mode, it will cancel the waypoints and stay in RTH mode until you regain contro ...

    hi,my friend.that' right.  if the copter know that the battery is low then it will notice you to make it fly home.
There's a warning on app if the power is lower than the first or second low voltage.
the copter will fly home ifself if the voltage is too low.

I'm going to take a stab at possibly helping the interference issue.  I watched your video and it looks like there wasn't that much wind for that day based on the smoke coming out of those chimney's.  So even if/when your bird dropped below 6 satellites it shouldn't have taken off like that, unless there were winds higher up of course...

I was experiencing the some of the same issues but mine were mainly due to interference when recording and my satellite connections would bounce from 6-3 while flying.  I could never fly missions or even hold a steady hover at 200'.

I moved my GPS circuit to the outside of the shell, wrapped the middle of the plastic body with the copper EMI sheilding tape, also wrapped the wiring with the same tape and topped it off with the non-conductive tape.  On the inside of the shell I left the factory EMI sheilding in place so now my GPS has been isolated from the inside wifi and other electronic components.

I have not had ANY issues flying and staying connected to a minimum of 8-10 satellites now.  I can hover just fine at 350'.  

I know my response may be a bit "off topic" but maybe not.  My bird appeared to be flying away but the wind was pushing it because I had lost GPS.

I hope this helps some.

Can you post a pic?

troyg@nextstepc Posted at 2014-12-12 00:54
I'm going to take a stab at possibly helping the interference issue.  I watched your video and it lo ...

Good detective work You're right, there was no wind that day.

In the end, I think (and hope) that the flyaway was caused by bad GPS reception doubled by weak transmitter signal (or slight interference). I've read that the reception may be weak if the drone is aligned with the tip of the antenna.
For whatever reason, I think the drone decided to perform an incorrect "return home" to a location situated a few hundred feet away from me. I think this is the case based on the fact that (in the movie) the drone eventually moves straight and then goes down (almost trying to land in a tree).

I've taken these steps to avoid issues like this in the future:
- pay extra attention at take off (not start without flashing green lights confirming GPS lock and setting of home point)
- rerouted the GPS cable under the isolation for improved GPS reception
- enabled NAZA mode so, in case of a rogue fly away, I can switch to ATTI mode and try a manual recovery
- pay more attention to the number of GPS satellites and start using GPS Plan application
- played with dynamic home point (I'm not yet sure if that is really going to help - but the GPS location on my phone is quite reliable)
- set a higher altitude for "return home" (220 feet instead of 60 feet) so, in case of a return home, the drone will avoid high trees
- I'm still getting myself familiar with course lock - in theory, that should work as long as compass readings are good and I know the original orientation of the drone at take off + pay attention to the bottom left indicator for drone location and orientation

Any more suggestions?

ciprianboboc@gm Posted at 2014-12-12 09:49
Good detective work  You're right, there was no wind that day.

In the end, I think (and hope) t ...

"IF" the rerouting of the GPS wire does NOT give you that much more reliability (didn't for me) I would move the GPS circuit to the outside and shield the outer shell middle.  I would never see > 6 satellites until I did this.  Now I stay synced up to no less than 8, bouncing from 8-10.

I too need to read up on NAZA mode.  I don't know too much about it as I'm still in n00b school when it comes to this.

if its losing GPS signal shouldnt it just be going into atti mode by itself instead of flying away?