I was on a shoot with strong winds.  Had to take-off down wind of a large truck.  Flight was going OK when all of a sudden the Phantom took off fast. Went LOS but I could not get a lock on the orientation.  No matter what control input, the Phantom just disapeared downwind and it was out of sight in seconds.  I turned off the Tx.  Watch the video for the result.
I have 232 flights on this Phantom, total time, 37 hours.  Never ever had this happen before.  DJI app programers please consider implementing my suggestion at the end of the video.
Note the 1st video is unlisted.



Oh and I did finish the shoot, here is the video.

Amazing and lucky!!  Was it necessary to switch the transmitter off - would it have returned home regardless? Or is it better to simply turn it off?

You made a right decision!　I'm glad your phantom got back!

Excellent suggestion about the GPS warning. Very nice finished video!

Glad u saved the bird, excellent harvest video Humming.uav, where about taken ?

Great suggestion! Glad that all worked out well.

RC Noob Posted at 2015-10-12 01:57
Amazing and lucky!!  Was it necessary to switch the transmitter off - would it have returned home re ...

If the Phantom loses the connection it is supposed to return home on its own. By turning the Transmitter off Hummingbird did a Hail Mary which I have only done once in a panic, and it worked out well. Great Lesson here for all. Just insure your Return Home Height is set right for your Terrain.

RC Noob Posted at 2015-10-11 23:57
Amazing and lucky!!  Was it necessary to switch the transmitter off - would it have returned home re ...

If it regained GPS lock with the Tx on it should have stopped way down wind.  I would have to press RTH button or fly it back.  By the way it took off I didn't know if it was controllable.

Nice job on your production. Very informative.

1999fxd@gmail.c Posted at 2015-10-12 06:15
Glad u saved the bird, excellent harvest video Humming.uav, where about taken ?

I was amazed it came back too.  The video was shot near Edmonton Alberta Canada.

Great video they sure made light work of clearing that field, amazing! Glad you recovered it and all turned out OK.

And that's why you should practice atti mode.  When GPS fails, make the switch and fly it back to landing ASAP to troubleshoot.

Nice suggestion and one more - show the wind speed, during the fly, and after GPS signal Lost Warning message may change the color from yellow to red depends wind.

can you please email me these flight logs? ken.booth@dji.com

Both device and craft logs, please.

I see three things... The one combine is only taking half a header of grain which isn't efficient, the dude in the wheel chair is likely at fault, and once the phantom regained sats, it still didn't quite "lock on" as usual. Ok, one thing I guess... You can see it stammer aiming a bit to the right of home, and gradually work its way to a direct approach. I find this odd as in my experience, once a GH function is set, it snaps in place when it locates itself. Anyone agree it was a bit of a soft approach? Maybe it was still sorting some GPS interference - maybe it was a software glitch.

(before anyone seeks revenge for the wheelchair remark, keep in mind I'll be fighting back from my mobility scooter as a partial paraplegic. It's an "inside joke")

Nicely done.  Perhaps consider you are flying over a dozen combines with active GPS receivers, each of which is of course an oscillator at the "front end".  Given that you have certainly accrued extensive experience with your aircraft, and there is no obvious aircraft fault, perhaps it's not so inconceivable to consider your environment there to be the cause of losing most of your satellites so dramatically.  Consider that if solar activity were the culprit, those GPS equipted combines would be scrambling around like a first graders forklift party.

Indeed I'm making some assumptions, but to loose 10 sats almost instantaneously is highly unusual under normal conditions in clear air.  For sure I'm glad you recovered and RTH finally kicked in.  Still scratchin' mah head .. thanks a million for positing .. Nicely Done.

Maybe the auto-switching from GPS to ATTI have to be briefly notified (warned) in order to pay appropriate attention. This way the pilot should be properly notified that the aircraft need full attention and control. Thanks for sharing the video and all additional explanations! Totally happy to see your bird is back to home healthy

kelly@myautorep Posted at 2015-10-13 22:57
I see three things... The one combine is only taking half a header of grain which isn't efficient, t ...

I think the rate of return was affected by the wind speed.  The last ground speed indication was 12.9m/s.
Normal RTH speed is ~10m/s.   Max calm air speed of a phantom is ~14.5m/s, thus it had to pitch full forward to return upwind and then only at about 3 to 4m/s.

attaboy@basicis Posted at 2015-10-13 23:19
Nicely done.  Perhaps consider you are flying over a dozen combines with active GPS receivers, each  ...

Oh I'm quite sure some interference from the combine knocked out the GPS reception on the phantom.  The combine GPS receiver was probably not the culprit, however I subsequently learned that some combines transmit a signal for the transfer wagon to use so that it matches speed and position with the combine as the grain is transferred.
Without the high wind, the GPS loss would not have been an issue.  When ATTI activated the phantom was accelerating away very fast.  As you all know there is a little lag in the streaming video which made it hard to gain control, switch to LOS but I couldn't determin orientation before the phantom was out of sight and I thought it may have crashed.

ag0n Posted at 2015-10-13 11:43
And that's why you should practice atti mode.  When GPS fails, make the switch and fly it back to la ...

I have no problem flying in ATTI mode when I know I am in that mode.  Had I known the instant it happened I would have been in a better position to control the phantom and why I requested a more visible warning on the screen.

Happy you got the bird back!
May i ask you the day you shoot this?
I've discovered just few weeks ago how the sun can cause severe interferences on GPS and i've installed k index monitor on my android phone to check space weather conditions before every flight..

http://www.tesis.lebedev.ru/en/magnetic_storms.html

this website reports also current solar activity and has historical recordings...

sorry, i didn't watch your video entirely...at the end you mention the k index.... i was looking for the effect on our bird of k index, i mean how this threshold level can affect gps lock in the phantom... but i cannot find any historical data..

I have got a similar situation, but without a wind and radio signal loss.
I got a compass error, Phantom switched to atti mode and i got vision loss. It was happily at about 80 meters and there was no high obstacles. After a loosing of vision i pushed the throttle open to climb and i pushed RTH button. Over a dozen of seconds Phantom got GPS back and start a RTH procedure. After a few seconds i got vision back.

It is important to climb at emercency atti situation to get safe altitude (to avoid obstacles and get a clear radio area, altitude stabilisation is still working), have a not obscured line of sight, set a safe RTH altitude, and correctly recorded homepoint, and after that even if phantom drif because of wind it will gain GPS soon or later and start RTH procedure correctly.   GPS/compass loss are temporary in most cases and after drift (or go higher by a climb) from 'jammed' area GPS-mode will back.

In my case, propably a metal bridge below caused a compass error

Ok, now I grew up a Kansas boy and I have never seen a full scale production of grain harvesting like that before EVER!  I mean, it seems to be a full scale, family oriented ordeal there!  LOL, I know this was about a near flyaway BUT I found the actual video quiet interesting seeing the kids running in the field!

A similar thing happens here in Australia when they get a group of harvesters together to do entire fields in one session, then they move onto the next farmer's field. Sometimes you get up to 20 harvesters in action.

jayhkr Posted at 2015-10-14 12:21
Ok, now I grew up a Kansas boy and I have never seen a full scale production of grain harvesting lik ...

This is actually a group of farmers who got together, planted and harvested a crop and then donated the crop to an organization that feeds the hungry of the world.  There were over 200 of these "grow ops" across Canada this year.  http://foodgrainsbank.ca/

When you lost GPS, did you also lose video link?  Did you not have camera visual?  Also, when the copter went to ATTI can you have it set so it flies with no heading so returning to home is always just pull back on the stick and the copter comes straight back to transmitter?  Sorry foe so many questions but my Phantom 3P arrives today and I worry abut this problem.  Thanks

hummingbird.uav Posted at 2015-10-14 09:14
This is actually a group of farmers who got together, planted and harvested a crop and then donate ...

That's awesome!  Faith in humanity is still alive!

Don Loftus Posted at 2015-10-15 00:31
When you lost GPS, did you also lose video link?  Did you not have camera visual?  Also, when the co ...

No I did not loose video however the camera was tilted downward and thus made it hard to see what was happening.  The underlining condition was I was flying in a 25mph wind so the instant GPS lock was lost the phantom blew away with the wind.

Kyokushin Posted at 2015-10-13 14:36
I have got a similar situation, but without a wind and radio signal loss.
I got a compass error, Ph ...

While the combine's GPS may have been a contributing factor, depending on where you fly may have some magnetic anomalies.  Perhaps if your compass heading doesn't calculate with where your GPS thinks it should be, the bird temporarily burps and chokes on conflicting incoming data.  Here is an example from my neck of the woods quoting directly from the latest FAA Sectional VFR chart for San Francisco; "Magnetic disturbance as much as 8* exists along the shore at sea level between Point Arena and Gualala".  This is along the San Andreas Fault line .. probably more than just a coincidence.  If you have such maps/charts  for your area it's probably a good idea to have them anyway as the DJI NFZs are a work in progress.

Where did you get the video of the flight path?  I know you can view this in the DJI app, but does the app actually save a viewable MOV or MP4 video file that you can use in the editor?  I've seen a few ppl use the map flight path and the actual video in a Picture-In-Picture format and I would like to do the same, but I need to know where folks are getting the map flight path video from.

Flight Raptor Posted at 2015-10-15 13:09
Where did you get the video of the flight path?  I know you can view this in the DJI app, but does t ...

You can use share the screen to sent it to another device that has a screen recorder running on it.  However I did this the old fashion way by recording it while it played with a pocket camera.

hummingbird.uav Posted at 2015-10-18 18:42
You can use share the screen to sent it to another device that has a screen recorder running on it ...

Much appreciate the response.   Keep forgetting about the legacy way of recoding a playing video with another video device just 'looking' at the playback :-)   Thanks!

I have two suggestions that might have helped out:

1. Press the return to home button on the front of the controller instead to switching it off.  This would allow you to see while it free home.

2. Check the UAV forecast for GPS viability prior to flying that day.  http://www.uavforecast.com  There are some days when GPS satellite positions are not good for flying.

Fulgerite Posted at 2015-10-19 11:03
I have two suggestions that might have helped out:

1. Press the return to home button on the front  ...

I looked at the GPS viability and it was moderate on this day.  I have never had GPS problems even on bad solar storm days.  I really thought the phantom was gone and possibly crashed in the field thus I shut off the Tx.  The wind was the biggest factor in this incident and how quickly it blew the machine away.

you got lucky, mine said compass error, then crashed, please contact dji and let them know

Shon.white Posted at 2015-10-20 06:29
you got lucky, mine said compass error, then crashed, please contact dji and let them know

They have my tablet and copter log files.

Jeje Amazing recover ,  im going to practice Atti mode or manual mode  to be prepared if it happen to me.

GTDrone Posted at 2015-12-17 16:41
Jeje Amazing recover ,  im going to practice Atti mode or manual mode  to be prepared if it happen t ...

Include some practice flying when it's windy in ATTI mode, that was my take-a-way from this flight.