Today the Phantom 3 Standard flew me. There was a big wind. Dron reported a error and then sped in one direction. At a distance of about 500 m, the control signal was lost. About 2 km away the image signal was lost. I have not found it yet. I suppose he flew up to 10 km.



Why did it happen?

As always, the recorded flight data may solve the mystery.

Go to http://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions there to upload your flight record from your phone or tablet.
Come back and post a link to the report it provides and someone might be able to analyse it and give you an understanding of the cause of the incident.

Can you please upload a copy of the flight log we maybe able to ascertain what happened.
I doubt very much that the drone will be up to 10 klms away. Is it posible you can follow its last known path on foot it would have to come down somewere along its last know direction.
It looks like you took off in atti mode not p mode and posibly took off from an area with strong magnetic interference like a reinforced concrete slab..
Did you wait till you had a strong gps fix with more than 10 satelites visible?
If you were getting these errors from before take off then why did you fly ?
Did you check that the home point was correct before your flight?

Hey Podes, I'm sorry to read your post. If the drone is still in warranty period, please contact the support and start a case: https://www.dji.com/support
Data analysis is recommended to check the exact status.

From what Post 1 says ... it was a flight doomed from the very start ... and should never have been made.

Nigel

Hellsgate Posted at 2018-1-7 15:54
Can you please upload a copy of the flight log we maybe able to ascertain what happened.
I doubt very much that the drone will be up to 10 klms away. Is it posible you can follow its last known path on foot it would have to come down somewere along its last know direction.
It looks like you took off in atti mode not p mode and posibly took off from an area with strong magnetic interference like a reinforced concrete slab..

The number of satellites was 11.
The flight mode was definitely P.
The last picture on the mobile phone display was 2.6 km away.
The flight took place in the wild at about 0.5 km from the HVV.
The first start and landing was ok and a second start from the same place happened.
The home point was written ok.

DJI Susan Posted at 2018-1-9 02:50
Hey Podes, I'm sorry to read your post. If the drone is still in warranty period, please contact the support and start a case: https://www.dji.com/support
Data analysis is recommended to check the exact status.

Dron was two weeks old.

I would upload the flight data as suggested in post #2, people will be able to give you a much better idea of what happened with hard data to work with, without that it’s just speculation.

Alan .. agreed but given content of posts 1 and 6 ... we seem to have conflicting info from OP ...

Ranges seem to tally between posts but not the P-GPS / ATTI / Compass bits ...

Log will tell better story - IF he ever uploads it ...

Nigel

What is Yaw Error?

Yaw is horizontal rotation.

Yaw Error is when AC is supposed to stay facing a direction but AC turns and will not stay steady in facing that direction.

Nigel

I know others are going to be much better at commenting on the log data ..

1. It is bad to go so high vertically over the controller ... this is the weakest RF signal orientation .. and at 2m 15s - it loses signal. You are at 671ft above yourself !
2. At 2m 36s it detects errors and switches to ATTI mode ... then shows Magnetic Interference ... with Yaw Error. Yaw or horizontal rotation uses COMPASS to determine which way the AC is facing. Without forward movement - the GPS etc. cannot help, it can only keep that location. Magnetic interference is throwing the Compass out of true.
3. From point 2 the AC then is moving away from you - it would have been better to land right then ... especially since you are now in ATTI mode which is basically manual flying.

The AC basically is at 500+ft altitude and flying away without Compass at max speed .... and in ATTI mode there is no GPS for position hold or control - it will only provide RTH if Home Point recorded correctly. But with Yaw Error (compass malfunction due to Magnetic Interference etc.) - it cannot make the turn to direction needed for RTH.

That's what I see in the data ... and as I am sure - others better at reading Log data will come in with better interpretation ...

Nigel

OP went straight up to over 500 ft without appreciable distance from home point. When it lost signal(dead over head) since it was within 60ft  in relation to the ground  home point, it initiated auto landing. Unit then when into atti mode, looking like an attempt to gain control(guessing). The "big wind" may have been the factor in the yaw error, although Im not sure about that. Unit never got back into Pgps mode even though it was clearly within range early once it started "drifting" away.

stuka75 Posted at 2018-1-9 08:58
OP went straight up to over 500 ft without appreciable distance from home point. When it lost signal(dead over head) since it was within 60ft  in relation to the ground  home point, it initiated auto landing. Unit then when into atti mode, looking like an attempt to gain control(guessing). The "big wind" may have been the factor in the yaw error, although Im not sure about that. Unit never got back into Pgps mode even though it was clearly within range early once it started "drifting" away.

....... yes .... but note that once the Yaw Error comes in with Magnetic interference - GPS mode went out the window and he's in manual ATTI mode ...

Nigel

In post one it states a compass stuck error before take off, but it doesn’t look like the drone was restarted.  I can’t see the stick inputs from the log but it doesn’t appear that much attempt was made to bring the drone down and land manually.

So I have a few questions:
- why the error occurred, "Yaw Error"?
- why the "Magnetic Filed Interference" error occurred?
- why did not the "Return To Home"?
- where is the probable location of the emergency landing?

My calculation:
Start battery: 98%
Battery stop: 69%
Difference: 29%
Landing Batteries: 15%
Remaining batteries: 69-15 = 54%

Start distance: 0 ft
Stop distance: 8328 ft
Distance difference: 8328 ft
Distance to 1% battery: 8328/29 = 287 ft
Other distance: 287 * 54 = 15507 ft = 4727 m

"So I have a few questions:
- why the error occurred, "Yaw Error"?
- why the "Magnetic Filed Interference" error occurred?
- why did not the "Return To Home"?
- where is the probable location of the emergency landing?"

We cannot see your warnings on display screen - but you reported STUCK COMPASS. That will create the YAW ERROR - because that is directional function.

Magnetic Interference - that can be due to many things but usually due to metal structures / reinforced concrete / faults in AC ... basically the Compass is being thrown off and FW detects error - shows Magnetic Error warning.

Return to Home as I explained earlier is impossible if the Compass cannot say which direction the AC is facing ... you had YAW ERROR - which means faulty directional function.

Possibly in a reasonably straight line continued on from last position recorded. A P3 battery from full charge will fly for approximately 13 - 14kms straight line distance in calm / near calm conditions ...  If wind is with it - then the distance increases ... if wind is against it - distance reduces. Its very difficult to predict. BUt your starting point is of course last recorded position... then continue on.

Nigel

Another calculation:

Flight time to stop: 6 m 50 s = 417 s
Start battery: 98%
Battery stop: 69%
Difference: 29%
Landing Batteries: 15%
Remaining batteries: 69-15 = 54%

Time to 1% battery: 417/29 = 14 s
Remaining flight time: 14 * 54 = 776 s
Speed: 24.6 mph = 10.99 m / s
Distance of the remaining flight: 776 * 10.99 = 8528 m

I don't know the answers to your questions but it looks like as others have also said.....you were kind of doomed from the get go. If you had a compass error and were instructed to restart but didn't, it just went downhill from there. Hard to tell what caused the magnetic error since you were straight up. I guess why were you going so high up right over yourself? That is the worst place to be for reception. You may have had some problem within your compass and it just couldn't recover itself. With it being in Atti mode, you RTH is gone........no GPS to guide it. Not sure what you are trying to do with your calculations, but it could be anywhere, and depending on the wind, those calculations don't offer much guidance in my opinion. Best of luck to you.

Small correction Ric ...

"With it being in Atti mode, you RTH is gone........no GPS to guide it. "

ATTI mode still uses GPS for RTH if sats are there. GPS is not used for positional stability that's all. ATTI mode for positional stability only uses Barometer for height ... and is why it drifts around. But it still will use GPS if the Home Point is recorded and sats available. Page 11 of Pro / Adv manuals, Page 10 of Standard.

Problem here of course is his lack of Compass ... giving Yaw Error. SO RTH is not available.

Nigel

solentlife Posted at 2018-1-9 03:39
From what Post 1 says ... it was a flight doomed from the very start ... and should never have been made.

Nigel

Maybe, maybe not - it doesn't say the big wind was present at the beginning of the flight,  It is possible, maybe not probable, that the wind started suddenly during the flight.

solentlife Posted at 2018-1-9 10:15
Small correction Ric ...

"With it being in Atti mode, you RTH is gone........no GPS to guide it. "

Hey thanks Nigel, I agree with you now that you explained it. Yeah I was forgetting that he did have satellites, and it looks like a home point was established right? Of course, just because it is in Atti doesn't mean it can't RTH. My bad, I'm thinking it isn't going to make things any different for this fella anyway.

I have a question to you Nigel, (not trying to jack this guys thread, but we are talking about compass errors)
I have never had the "compass stuck" error. What exactly does this mean? We have probably all had the dreaded compass error, and I get that, but the "stuck" is throwing me. Now I don't really understand what is going on inside the compass either. It is so small I assumed there were no actual moving parts, but again I don't know how it works. Can you offer any explanation?

Next question:
Is it possible to use the compass error to apply the warranty?

Podes Posted at 2018-1-9 15:49
Next question:
Is it possible to use the compass error to apply the warranty?

You appeared to take off from that dirt road in the map, did you lift off from the road, or take off from some other surface? Had you calibrated your compass just before flight?

Podes Posted at 2018-1-9 09:57
Another calculation:

Flight time to stop: 6 m 50 s = 417 s

It's very hard to say where the Phantom would be
But .....
Your Phantom can't fly until 0%
When the battery reached critical low level of around 10% it would have tried to land.
Here's a very rough calculation just to get a ballpark idea .....
The battery was losing 1% in 13.8 secs (this rate probably increased as the battery level got lower)
It would have reached critical level after approx 14 minutes.
At 24 mph (the speed the wind was pushing the drone), it would cover another 5 miles from the last recorded location before descending which would take another minute.

Looking at the data, your problems started at 2:36.4 with the Phantom 520 ft directly above the launch point.
After that you didn't touch the joysticks at all and let the Phantom blow away at 20-26 mph.
The yaw error meant that you had no position holding ability and may have made steering tricky ... BUT the left stick would have worked perfectly to bring the Phantom down out of the high level winds and get it on the ground.

The yaw error is puzzling - they are commonly caused by launching from steel or reinforced concrete surfaces but usually show earlier in the flight.
There may be another cause in this incident.

Geebax Posted at 2018-1-9 16:17
You appeared to take off from that dirt road in the map, did you lift off from the road, or take off from some other surface? Had you calibrated your compass just before flight?

The start was on a normal paved asphalt road.
I calibrate the compass before every start.

Geebax Posted at 2018-1-9 16:17
You appeared to take off from that dirt road in the map, did you lift off from the road, or take off from some other surface? Had you calibrated your compass just before flight?

This Google map is old, now there is a nice new road.

Podes Posted at 2018-1-10 00:40
The start was on a normal paved asphalt road.
I calibrate the compass before every start.

Calibrating the compass is not needed or suggested before each flight.  You risk having a bad calibration.  Once the calibration is correct, you should be able to fly for months with the good calibration.  If you get a compass error before flight, try moving the drone a few meters to launch instead of doing a compass calibration at that launch site.

Podes Posted at 2018-1-10 00:40
The start was on a normal paved asphalt road.
I calibrate the compass before every start.

Oh dear. As has been said many times on this forum:

Amazing how many fly-away threads start with "I calibrated the compass as I always do"

RicardoGray Posted at 2018-1-9 12:18
Hey thanks Nigel, I agree with you now that you explained it. Yeah I was forgetting that he did have satellites, and it looks like a home point was established right? Of course, just because it is in Atti doesn't mean it can't RTH. My bad, I'm thinking it isn't going to make things any different for this fella anyway.

I have a question to you Nigel, (not trying to jack this guys thread, but we are talking about compass errors)

Stuck compass just means it has no yaw capability ... the Compass here is electronic without any moving parts. Its a term that covers all evils.

Nigel

I still come back to post one which states the compass was stuck before take off,  was this for this flight.

Podes Posted at 2018-1-10 00:40
The start was on a normal paved asphalt road.
I calibrate the compass before every start.

Normal Asphalt road usually is what is termed "Metalled Road" .... wrote many transport reports with that term in !!

Anyway - roads usually have pipes, cables, services under or close alongside. These can seriously affect Compass .. and calibrating there will create a 'bogus' calibration that can easily result in error once AC flies enough distance or height out of the influence. This then would be shown as Magnetic Interference ...

It is has been said many times by many - ONLY calibrate if absolutely necessary. Usually one calibration on good area should be only one you need unless repairs to model.
If you get Compass Error when starting up ... power off ... move a few metres and power up again. Often there's an old pot or something in the ground ... or a cable etc.

Unfortunately the most popular location to power up is garden or front drive ... both often have Magnetic influences ...

Nigel

Labroides Posted at 2018-1-9 16:57
It's very hard to say where the Phantom would be
But .....
Your Phantom can't fly until 0%

mmmm seems to roughlly agree with my reasoning as well ... I reckoned about 13 - 14kms ...

Cheers
Nigel

AlanHd Posted at 2018-1-10 03:19
I still come back to post one which states the compass was stuck before take off,  was this for this flight.

Agreed and is why I think he should have aborted and investigated.

Nigel

Geebax Posted at 2018-1-10 02:46
Oh dear. As has been said many times on this forum:

Amazing how many fly-away threads start with "I calibrated the compass as I always do"

Those simple words !!

Nigel

After switch on drone, back LEDs blinked yellow.
After compass calibration, back LEDs blinked green.
Sometimes the compass calibration did not finish ok, and then the back led blinked red.
That's why I calibrated my compass every time I turned on.

solentlife Posted at 2018-1-10 03:14
Stuck compass just means it has no yaw capability ... the Compass here is electronic without any moving parts. Its a term that covers all evils.

Nigel

Hey thanks for the compass explanation. It didn't seem reasonable that it would have any moving parts inside but I didn't know.
I am with the rest of you as far as taking off from that road. I will absolutely not do that. I had bad experiences doing that, and like everyone agrees, there is generally something underneath that payment, even if it is blacktop or asphalt. For sure if it is concrete.
I think everyone is trying to tell him and anyone else that has compass errors taking off or shortly after.....STOP and bring the bird down and start over. Too much at risk to try to continue.

Thanks to all for advice and info.
Now I know the best thing was to run the dron quickly down.
But I was so frightened of the situation that I was unable to regain anything.
Lack of experience, I only had him for two weeks.

It’s a costly lesson, my advice would be to find a wide open space and practice putting the drone into ATTI mode (you can always flick it back into gps mode if you lose your bearings) the more familiar you are with it the less chance of panicking when you do get a genuine problem.

Podes Posted at 2018-1-10 03:52
After switch on drone, back LEDs blinked yellow.
After compass calibration, back LEDs blinked green.
Sometimes the compass calibration did not finish ok, and then the back led blinked red.

And that is part of the problem ...

Each time you calibrate - you fix it for local circumstances ... and if you keep doing it in such as roadways / driveways etc. - you are asking for trouble.

When people ask me about calibrating ... and ensuring a clean job ... I suggest :

System a :

Find a nice clean open area preferably not a football or sports field as they usually have pipework and gear under the surface. But a municipal park where dogs walk .. general non sport area. Or better is a farm field. Calibrate there and then LEAVE IT ALONE !!

System b :

If you really want to be super serious about it ... get a hand compass. Find an area that is open and clear. Look at the compass and where needle is pointed - reference to a far of marker or point. Now walk around and see what happens - you will likely see needle deviate at times  from that marker showing that something is there ... What you are looking for is the most consistent needle location, as first place my not be best. Once you have that best location ... do your Calibration there.

OK - you now have your P3 compass calibrated .. system a is fine ... b is only as info.

Do not change it ... if you get a Magnetic warning come up - that means the LOCATION is problem  - not the P3 ... Power down and move a few metres and power up again.

I advise to power down and up again because I have had on many occasions the warning refuse to cancel when moved. But power down and up and it clears.

It is well to remember the place as well. I have a specific spot in my grounds - I have 3.5acres round my house where I know is good for calibration.
I also know where its bad.

NEVER:
try calibration on top of concrete slabs because they usually have re-bar in them ... try to be clear of buildings ... cars ... trucks ...
Not in Mall Car Parks - they are terrible for cables etc.
Pedestrian precincts


................

Nigel