I bought a Phantom 3 Professional just over a month ago, and lost it last week due to a flyaway.   I got a compass error in mid-air and immediately lost my RC signal, so I was unable to manenuver it back.   DJI is saying that it is due to electromagnetic interference and not malfunction.  The location that they said is a bakery, and I don't understand how a bakery could have so much interference to cause a fly away.  I know the area pretty well where it happened, and nothing in that area jumps out at you as being an electromagnetic interference location.
I feel that there was some sort of defect in the unit, because  I also had the same compass errors whille visiting in Michigan a few weeks prior.  These are locations that I flown prior with my Phantom 3 Standard, and never had any errors.  DJI offered me 15% off a Phantom 3 pro AC.  Can't really afford it right now.  Also considering other options, but would rather stay with the DJI brand.

Genuine flyaways are rare. Compass errors can cause the aircraft to fly erratically, but you should always be able to switch to ATTI mode and bring them home. If you would like others here to offer an opinion, upload the flight records from your device to Phantomhelp http://www.phantomhelp.com/LogViewer/Upload/ Follow the instructions to upload your flight record. Then come back and post a link here so it can be viewed.

Geebax Posted at 2016-7-8 19:54
Genuine flyaways are rare. Compass errors can cause the aircraft to fly erratically, but you should  ...

I didn't have a chance to fly it in Atti, because the RC went out immediately.  

Flight log is here
http://www.phantomhelp.com/LogViewer/BGHL89P76RBB7Y9YSOYP/#

losman26 Posted at 2016-7-9 10:32
I didn't have a chance to fly it in Atti, because the RC went out immediately.  

Flight log is he ...

Are you sure you lost control or did you just lose the return video feed? In most cases the return video feed goes first, but that does not mean you lose control over the aircraft.

Looking at the data, you were near to 400 Feet up, close to maximum legal altitude, and in the last part of the flight, the aircraft was travelling between 50 and 60 mph. RTH had been triggered, but I am thinking that you were in a high altitude air current that was taking the aircraft away from you. Speeds of 50 to 60 mph are way faster than a P3P is capable of. At the same time there was a lot of compass errors, and these were throwing the aircraft into ATTI mode, so it's position holding would have been poor anyway.

My guess is that compass errors combined with high altitude winds blew your aircraft out of reach, and it did not have the power to fight the wind. The compass errors do not mean the aircraft was experiencing abnormal compass readings in that position, it may simply mean your compass calibration was not done in a favourable place. As a result the aircraft could not resolve the difference.

Geebax Posted at 2016-7-8 21:02
Are you sure you lost control or did you just lose the return video feed? In most cases the return  ...

had no video, no RC, no signal.  Nothing as soon as the compass error hit.  Wind wasn't that bad that particular day.

losman26 Posted at 2016-7-9 11:21
had no video, no RC, no signal.  Nothing as soon as the compass error hit.  Wind wasn't that bad th ...

You would know that you had no video, but the link from the RC unit to the aircraft is not really noticeable, so you will not have seen if it was still there.

As for wind, it can be vastly different at 400 feet than it is at ground level. The speed of the aircraft seems to indicate high wind.

Geebax Posted at 2016-7-8 21:49
You would know that you had no video, but the link from the RC unit to the aircraft is not really  ...

yep, everything went out.  I don't remember going 400 ft either.  Everything happened too fast to react.  Distance wasn't that far, as I had been flying over well over 1,200 feet distance ealier in the day with no problems whatsover in that neighborhood.  I use the UAV forecast to estimate the wind speed at 400 ft as well.  I don't fly in anything above 15 MPH at 400 ft.  It was a pretty average day.

It's just strange, that I had flown my P3s way more than my P3 Pro, and never once got a compass error.  Never.  And I would fly that thing everywhere..  I get a P3 Pro and it happens on 4 different occasions mid air, with me losing the thing on the last time.

losman26 Posted at 2016-7-9 12:03
It's just strange, that I had flown my P3s way more than my P3 Pro, and never once got a compass err ...

I wonder when was the last time you did a compass calibration on the Pro? Usually a compass error in the air means you either flew close to a massive steel structure, which does not seem likely in your area, or you got a bad location when you last did a calibration.

Geebax Posted at 2016-7-8 22:35
I wonder when was the last time you did a compass calibration on the Pro? Usually a compass error  ...

I  do one right before flying, and since this was a new location, I defintiely did one.  The speed errors, GPS, Yaw, and compass errors, losing video feed and RC signal all at once don't make sense

IF there were GPS errors, speed could be reported at some strange numbers.  Same for location.  I remember way back with my Garmin III+ when there was a GPS erorr that showed my speed at some 700+MPH in my truck.  My path jogged quickly about 80 miles off of where I was and back.  I was shocked when I saw that.  It CAN happen.  

AG0N-Gary Posted at 2016-7-8 23:04
IF there were GPS errors, speed could be reported at some strange numbers.  Same for location.  I re ...

Nothing to me makes sense out of this flight.  Just wish I was able to fly the thing back in ATTI mode, because I'd still have my phantom.  Now, I'm unsure of what my next move will be.

losman26 Posted at 2016-7-9 12:58
I  do one right before flying, and since this was a new location, I defintiely did one.  The speed  ...

That compass calibration was probably the cause of the errors. I do not calibrate unless I absolutely have to, because there is a chance you will get a bad calibration and end up in trouble. Much like what happened to you. Sorry to say so, but I think that might be the cause of the incident.

The speed may have been an error, but it seems like the aircraft was tripping back to ATTI mode a lot because of the errors, and while it is in ATTI mode, it is at the mercy of the wind.

Geebax Posted at 2016-7-9 01:30
That compass calibration was probably the cause of the errors. I do not calibrate unless I absolut ...

So I have been using a p3S for months with no bad calibrations, no compass errors,  yet all of a sudden I buy a professional and get compass errors mid-air on 3 or 4 different occasions?  Wind was not that bad that day. Sorry, but I'm not buying it.

losman26 Posted at 2016-7-9 12:58
I  do one right before flying, and since this was a new location, I defintiely did one.  The speed  ...

Were you watching the aircraft directly or were you relying on a first person view from the camera?   When was the last time you had eyes on the aircraft and what direction was it traveling?  Did it correspond with the flight track returned from Phantom Help?  I've looked at the data and nothing much is jumping out at me as being "broken".  There are disturbing high speeds reported with a max of 66mph.  There are fluctuating pitch/roll/yaw readings as well as headings.  I've seen similar readings reported during crashes when the aircraft is tumbling and falling, returning strange readings which don't pass the sanity check -- e.g. the system is saying I just saw we were at -30 degrees roll and here we are 0.1 seconds later at +90 degrees. I can't explain how we got here that fast, it is beyond the capabilities of the aircraft, so I'll just report an error.  Compass errors make it lose reference to its position on the map.   Not accurately knowing which way is north is not going to make it take off like it has rocket motors attached.  Getting caught in a strong wind would explain the data that was returned.  You were getting speed errors before anything else.  It did not just shut down, you did not just lose everything immediately.  The RC was receiving telemetry for 2 min 2 sec.  You got your first speed error at 60 seconds and a slew of positioning errors from 75 seconds until the end of the flight record.  Yaw errors were reported at around 90 seconds before RTH was initiated.  Again, if the aircraft had made a -90 degree yaw maneuver but high wind was preventing it from carrying it out, an error would be returned.  The aircraft seemed to be attempting to turn but was being carried away from where it was expecting it to be.  This could have been compounded by compass errors, when it is trying to determine if it has turned enough, has it moved enough etc.  I don't see any compass errors early on (your take-off ascent was straight  and not wobbling all over the place), suggesting to me that your calibration was OK and something may have upset it later in the flight.  I notice it started somewhere over the railway tracks.  When you "lose control" I notice it get sucked upwards and into a spiral slipstream with a rapid increase in speed (almost like it was sucked into the vortex from an aircraft landing on runway 34 at Westchester County Airport...):




Be aware that even though the air may be perfectly still at ground level and your wind forecasts are favourable, high winds can pick up at altitude quite severely and without notice.  I would have to concur with the analysis presented by Geebax .

I was watching at looking at the tablet on the map.  Everything seemed fine until that compass error.  Winds were not that bad, trust me.  I do not fly in windy conditions, after almost losing my p3S.  
I'll be you guys that I could fly the same route with my P3s, and not get a compass error, and all the errors followed.  I got defective unit, IMO.  Compass errors just don't happen in mid-air out of nowhere.  This happened to me on 3-4 different occasions,  one of them being flying over a lake.

losman26 Posted at 2016-7-10 00:47
I was watching at looking at the tablet on the map.  Everything seemed fine until that compass error ...

The way that the compass works is not as you would think. A compass error in the air does not always mean you flew near to anything metal, and the compass is a pretty simple device and does not change during a flight. A compass error in the air usually means the compass calibration done on the ground was not correct.


Once in the air, if the aircraft cannot resolve the compass information correctly, it switches to ATTI mode. That means it is not using GPS to position the aircraft any longer. At that point in time, any wind can carry it away as the there is no position hold in operation. The only way to recover from this is to switch the aircraft to ATTI mode and bring it home manually.

They offered 15% off aircraft only? If you used it for Advanced.... although more you spend the more 15% is... But still.. weird..  Never recovered the pro from wherever it crashed? Sad!
I guess technology is great, but stinks when it fails...  

Phantomski Posted at 2016-7-9 19:33
They offered 15% off aircraft only? If you used it for Advanced.... although more you spend the more ...

Yeah that's it 15%.  I gave up looking for it, because it's probably already in a pawn shop or stuck in a tree.  I'm getting a trackimo for the next drone, whatever it may be.  I really don't want an advanced, because I have  P3S with a DBS mod on the remote.  Love my P3S, never had a single problem with compass errors out of nowhere, and almost lost it twice to my own fault. It has been extremely reliable, and exceeded my expectations   I finally got a Professional and loved the thing.  Camera and range is amazing.  It took my videography/ aerial photography to another level.  I always flew cautiously with the Pro.   The random compass errors make me believe that I got a bad one, and not due to a bad calibration.  I'm considering other brands at the moment within the same level as the p3 Pro.  Would rather stick with the DJI brand though, because other than this one problem they haven't failed me.

Geebax Posted at 2016-7-9 18:23
The way that the compass works is not as you would think. A compass error in the air does not alwa ...

Kind of hard to fly in ATTI mode, when your RC signals drops out right away with not that far away from the home point.

losman26 Posted at 2016-7-9 19:33
Yeah that's it 15%.  I gave up looking for it, because it's probably already in a pawn shop or stuc ...

I feel your pain... u r sure u worked the case as much as you could? Some other brands are coming upthere, Blade Chroma comes to mind.. but it's a very different animal...  DJI seems to be the best at the moment... but sounds like you got unlucky... Perhaps if they looked at your other logs with compass errors, they'd decide one of the 2 compass sensors was bad? Not to give you a false hope, but... ;)

Phantomski Posted at 2016-7-9 22:18
I feel your pain... u r sure u worked the case as much as you could? Some other brands are coming  ...

Yep, total bad luck, and a lot of money to be out of after this one.  Question is, what would you think of if you had a P3S, flew it for 3-4 months with no problems whatsoever.  No compass errors, no speed errors, no GPS errors, no yaw errors.  Then you decide to upgrade, and the thing gives a couple of compass errors mid air while visiting your family in another state.  Places you have flown before with your P3S on previous trips with no problems.  You just deal with it, and think no big deal.  You come back from your trip, shoot some amazing videos, then a few days later, get a compass error, and a fly away at the same time.  It's pretty heartbreaking.  I really want to get to into real estate videography.  The area I live in, is perfect for that.  The Phantom 3 pro was perfect for honing my skills.

losman26 Posted at 2016-7-10 11:33
Yeah that's it 15%.  I gave up looking for it, because it's probably already in a pawn shop or stuc ...

I have just received my second P3P after a fly away. From the first flight of this new one I have been getting compass errors. I don't think I had one compass error with my original bird. WTF

thegaz99 Posted at 2016-7-9 23:23
I have just received my second P3P after a fly away. From the first flight of this new one I have  ...

yep, and the typical response is "you must have calibrated it wrong,  you must been flying into strong winds", every other response but "maybe the phantom was defective." I'd send it back, before you end up like me.

losman26 Posted at 2016-7-9 21:31
yep, and the typical response is "you must have calibrated it wrong,  you must been flying into str ...

Or if u bought it locally, just exchange it, and make sure they mark this as faulty.. woudl not want anyone else buying it as "good"

losman26 Posted at 2016-7-10 13:31
yep, and the typical response is "you must have calibrated it wrong,  you must been flying into str ...

OK, I get the message. The simple fact is that most 'fly aways' are not. And this one does not look like a genuine fly away either. But good luck with it, I won't bother you any more with rational thought.

Geebax Posted at 2016-7-9 01:30
That compass calibration was probably the cause of the errors. I do not calibrate unless I absolut ...

What he said. I have calibrated my compass one time, and that was the first time I flew it. I will not calibrate it again unless the numbers are really off. Unless you are flying hundreds of miles from your last flight your declination is not going to change enough to matter. Repeated compass calibrations are just asking for errors.

Geebax Posted at 2016-7-10 01:42
OK, I get the message. The simple fact is that most 'fly aways' are not. And this one does not loo ...

Sorry didn't mean to rub you the wrong way.  It's just that I have a hard time believing it when I never had a bad compass calibration during the 4 months of using the Ps3, and to me, actually being there and witnessing the event.  It was a flyaway.  

losman26 Posted at 2016-7-10 16:13
Sorry didn't mean to rub you the wrong way.  It's just that I have a hard time believing it when I  ...

That's OK, I am not offended. It is just that after looking at so many of these cases you begin to see where they can go wrong. I hope you get your aircraft back. BTW, I don't agree with the DJI view that it was caused by magnetic interference, not at that altitude.

losman26 Posted at 2016-7-10 04:36
Yep, total bad luck, and a lot of money to be out of after this one.  Question is, what would you t ...

I don´t think the Pro has a better compass then the S, the upgrade would be the camera and the range.
I crashed my first P3P due to compass error, took it to the dealer and exchanged it. Now on a P4 which only needs calibration when it tells you to. The P4 does not feel any more stable however. Dual confused compasses comparing their readings. What I learned is that the wind could be your enemy and that the craft will not take that into account when calculating the RTH. I usually fly around 500 ft and launch from a height so the winds up there are very different. I would keep pushing this but it´s hard when you don´t have the logs created internally in the craft. Good luck to you and hope to see you in the skies soon.

Swedrone Posted at 2016-7-10 02:54
I don´t think the Pro has a better compass then the S, the upgrade would be the camera and the ra ...

Yeah, I usually check out the wind on UAV forecast and set the altitude to 400 ft in the settings.  I don't fly if it's over 13 MPH at 400 feet.  

Swedrone Posted at 2016-7-10 14:54
I don´t think the Pro has a better compass then the S, the upgrade would be the camera and the ra ...

Hi, when you fly that high, it would be good if you test the wind speed after you reached that height. You can switch to atti and see where and how fast it is drifting. Or look at the speed of the drone to tell if it's flying faster than usual (downwind), slower than usual(upwind).

But yes, for a better analysis, you need the log file after you finished flying.

DJI-H.C Posted at 2016-7-10 13:06
Hi, when you fly that high, it would be good if you test the wind speed after you reached that hei ...

The ATTI mode was a very good tip! Never thought about that. I used to upload the logs afterwards to Healtydrones where the windspeed is shown. So I know that the winds up there are quiet different from the ground

Hey Guys,
I'm not trying to start anything.
No one seems concerned that he lost control of his drone over a residential area.
This is something that is always on my mind, not wanting to crash into a human being and injure them or crash into moving traffic causing a traffic accident.
Where's the safety?
What is on the top of the building where he loses control, I see some large ventilation units, but what is the other item?
Curious to hear some thoughts.

adrianthib-sp Posted at 2016-7-10 10:33
Hey Guys,
I'm not trying to start anything.
No one seems concerned that he lost control of his drone ...

I knew this one was eventually coming.  I was shooting a quick video of my friend's neighborhood, to give him a video, and was taking videos and photos of him with his son.  Would have prefered going to the water instead.

thegaz99 Posted at 2016-7-9 23:23
I have just received my second P3P after a fly away. From the first flight of this new one I have  ...

Knowing what I know now, seems like this sort of thing happens to other people.   I wish I had just replaced the compass for $15.  But I didn't expect a fly away to happen all of a sudden like this.

04red6 Posted at 2016-7-10 01:58
What he said. I have calibrated my compass one time, and that was the first time I flew it. I will ...

+1

no calibration needed each flight,
almost every post involving words flyaway have the words " I calibrated my compass......"

2 years , 6 phantoms, no calibrations after they are set once and no lost quads or compass errors.

good luck and have fun flying!

kirk2579@aol.co Posted at 2016-7-10 14:38
+1

no calibration needed each flight,

I thought when we go to a new location that we should do a compass calibration.
If you are right, should we stop calibrating from now and all is good?

In one year, I have only calibrated my Phantom 3 Pro' compass maybe 1/2 a dozen times.
Mostly after a firmware update which includes an IMU and Gimbal calibration first.
It's not necessary to calibrate it before every flight, only if you move to a new location a couple of hundred miles away.

Agreed, also true, that doing continuous compass calibration, risks doing a bad one, and any compass errors may result in uncontrollable flight characteristics.
Even here, in O Canada. Haha
Alberta is actually home for many of us on here. ;-)

RedHotPoker

kirk2579@aol.co Posted at 2016-7-10 14:38
+1

no calibration needed each flight,

I didn't say that.Sorry misread the post