Hi everybody!

Would appreciate any input in this scenario that I experienced during two flights. Aircraft behaved very different and I found it hard to controll. Did manage to bring it back though, thanks to VLOS and not panicking.

The flights were made high up in a remote area, no buildings, no power lines, no constructions of any form. The terrain is sloping, so I flew out over kind of a hill. Altitude recorded therefore probably does not reflect the actual distance between the AC and the ground. Winds were not strong. Latest FW on AC and RC, latest version of Go 4.


I have flown three batteries at the same location before, no problems except GPS Postion NoMatch.


I powered on AC, checked status (all green) waited for good satellites as usual, then took off. Very short into the flight, while trying to go straight forward I got the feeling that the AC drifted to the right, approaching some trees. When trying to correct this I felt that I lost control, the AC not heeding the throttle commands properly. The flight log says 'YAW ERROR', and shortly after that Compass error and then went into ATTI-mode and then IMU heading error. Not sure if I got any messages in the Go 4 app though, since I focused on the AC. I got it back in, and it started to behave as it should. I therefore flew it out towards the same location, to see if the incident would occur again, which it did not. Also looks like the AC tried to update the Home Point a few times, but I really can't remember that I tried to do so.

I initiated RTH after a while and when the AC got back, it was about 1.5M off from the launch pad, so I had to manually land it.


So all in all a weird and unsettling flight.

Landed the AC and moved launch pad a bit. Sending the AC up at 61% battery. Did some flying in sport mode, overall felt that the flight went well and AC responded as it should. If it didn't, I didn't notice because being in sport mode. Flight Log show compass error when making sharp turns, also yaw error and IMU heeding error..

So what could this be all about, and should I be worried? Previous flights at the same area went fine, no errors except for GPSposition NoMatch at one flight there. I haven't changed or calibrated anything after the incident, having read that you should not calibrate the compass (and IMU?) unless being told to. Hoping to go fly this evening, I'm not really sure if I should be worried.

Might flash the firmware and calibrate the IMU at home befire flight. The compass calibration I would rather not have to do since a side note there is that I have stainless steel and six screws inside my hand, after surgery following an accident that crushed large parts of my hand. Thus this makes it pretty hard for me to calibrate without metal in proximity..

Thank you in advance for any input, please see the logs here:

https://www.phantomhelp.com/LogViewer/O570KYFMJG1QJN0D4DO4/

https://www.phantomhelp.com/LogViewer/P6N0M0VLKIGPKPFC6F44/

Oh, and also the log from the flight the day before, when I got a GPS Position NoMatch. I noticed that the log does not seem to complete, not showing the AC descending or landing. Just "vanishes" from the air. Seem strange, does it not?

https://www.phantomhelp.com/LogViewer/NAN4J3VQILHUISGG3I48/

You could calibrate IMU and compass, for now.

I was having the same problem a few days ago, but my OAS kept going off and stopping my spark in its track.  Even after turning it off in the settings it kept stopping my drone mid-flight.  I ended up just packing it up and sending it in for repair.  I forgot about the compass cail and all that, now wish I didn't send it in already.

NickEST1987 Posted at 8-17 20:35
I was having the same problem a few days ago, but my OAS kept going off and stopping my spark in its track.  Even after turning it off in the settings it kept stopping my drone mid-flight.  I ended up just packing it up and sending it in for repair.  I forgot about the compass cail and all that, now wish I didn't send it in already.

Sorry to hear that.. What happened mid air? You say that the Spark stopped?

What message did you get in the app?

Have you checked the flight log for any errors?

Also, what kind of environment were you launching from/flying in?

Guess you could have tried calibrating the compass before sending it in, but you shouldn’t feel bad, after they have checked it, you will know for sure that everything is working as it should and you know that the AC is safe to fly!

Also, if there is some kind of a problem, they will surely find it.

Flygmaskin Posted at 8-18 02:44
Sorry to hear that.. What happened mid air? You say that the Spark stopped?

What message did you get in the app?

It sucked cause I was looking forward to flying that day since the sun was starting to go down.  With the avoidance system enabled your spark is suppose to stop you from flying into things in front of you. Basically stop before you hit so you don't damage your drone.  Since I was flying in a open field with nothing in front of me it was a real pain to fly since it kept wanting to stop.

The only message I got on the app was the avoidance sound (a beeping).  I didn't get anything (that I recall) about any other messages until after I looked at the flight data on airdata.com

I'm really hoping to get my spark back soon as I miss flying already, have been alot of great sun sets/rises that i'm missing.

If you want to see my flight data the information can be found Here

NickEST1987 Posted at 8-18 02:57
It sucked cause I was looking forward to flying that day since the sun was starting to go down.  With the avoidance system enabled your spark is suppose to stop you from flying into things in front of you. Basically stop before you hit so you don't damage your drone.  Since I was flying in a open field with nothing in front of me it was a real pain to fly since it kept wanting to stop.

The only message I got on the app was the avoidance sound (a beeping).  I didn't get anything (that I recall) about any other messages until after I looked at the flight data on airdata.com

Whoa, that's alot of compass errors and yaw errors!

Hard for me to see in the log, but even after turning the avoidance system off, it still triggered mid-air (with nothing even being in front of the AC..)?

Have you been flying in that area before? And if so, without any issues?

Don't really know if it could have contributed to the compass errors, but it seems like there is a high voltage power tower about ~100m / ~340ft from your takeoff point. Not sure if that is "too close" and interference might be picked up. Other way more experienced users than me could probably give input there.

Sure sucks anyhow, I know the feeling. Just got a Spark, after only a couple of days something happened with GPS Position NoMatch and it drifted into a tree, damaging the gimbal. Was so frustrating. Have started a repair ticket and in the mean time got a new Spark (the one that made me start this thread..)

S-e-ven Posted at 8-17 07:47
You could calibrate IMU and compass, for now.

Might calibrate the IMU. But the compass, I'm not sure what to do.. There seem to be a consensus on the forum that you shouldn't calibrate unless told so by the app. Some believe that it can actually cause more problems than it fixes.

Dji's instructions on the matter are quite contradictive, if you compare the manual v1.6 dated 2017-10-31 with the beginner tutorial on key components on their Youtube page, dated 2018-01-15 you are adviced to do two opposite things.

The manual says only to calibrate when prompted by the app, the video on the other hand, says it is recommended to calibrate before each flight. Also, I've noticed that in the manual, the second step of calibration shows Spark with camera pointing down. In the video, the second step shows that the camera should point to the side. Might not make any difference, but still confusing.

I would appreciate if any official Dji representative could give me some input in what I would be best to do in this situation, and what could be the cause for these multiple Yaw and Compass errors..? Ofc metal objects could cause compass errors, but I was not in proximity to any larger metal object during this flight.

Also, should I go by the manual, or by the tutorial video?

Flygmaskin Posted at 8-18 04:05
Whoa, that's alot of compass errors and yaw errors!

Hard for me to see in the log, but even after turning the avoidance system off, it still triggered mid-air (with nothing even being in front of the AC..)?

I have flown at the location a few times and at the baseball park next door with no problems. I really want to say it had something to do with the last time I crashed my drone.  It hit the ground pretty hard

Am I doing something wrong?

Here we go again.. Yaw error, Compass error IMU Heading error.. Exit P-GPS mode.. Whent into ATTI for about 20 seconds. No problem, I could bring it down and control it. Got back the GPS reception, and AC behaved as it should. Then I made a stupid mistake to trust it enough to send it back up. Very high up actually. Higher than I should or can recommend. I must have lost track of the altitude, just marveling at the view and checking the sat count.

Suddenly, the nice lady in the app said "ATTI MODE". Didn't see that one coming with 19 satellites at full reception.. Shortly thereafter screen goes black. "Lost image". Really bad situation.

The AC drifted with the wind, 15-16 kph / 9-10mph had no clue where it was. No chance to get VLOS again because it went behind trees.

Even when I got image transmission back, I didn't know if I could trust the map and the direction either. When I compared what i heard with the clouds direction and the arrow, and it generally matched, I decided to go into sport mode to bring the AC down as fast as possible. Got it going towards me, and GPS finally came back up again, after what felt like forever. Almost 30 sec of ATTI, image transfer coming and going, high altitude.. I'm actually surprised I got it back. Could SO easily have lost it. Probably got it back more thanks to dumb luck then skill.

I definitely think something is wrong with this particular AC. I don't trust it anymore and it no longer feels fun to fly. Seems to me that the yaw error always come before the compass error, but no warning shows up in the app, thus giving you a hint. As soon as i stopped ascending, let go of the throttle up, compass error came and AC went away. Before this,I've had multiple yaw errors that I was not aware of.

Am I doing something wrong or Is this caused by defect in compass, poor calibration of compass, defect in GPS or what..? I've noticed in this flight log that the points on the map are off, by about 30-50 meters.

If I can't get some help by Dji remotely, I must try to return the AC to the retailer, rather then going through the procedure of sending it in.

The log: https://www.phantomhelp.com/LogViewer/CS719LGN741R7B0ET0O5/#

A few days ago I was in a remote place near the top of a hill hoping to shoot a cool reveal of the valley just on the other side. About 300ft up and 500ft out, the app lady said, "low GPS signal. Atti mode."

I could see where she was, so I pulled back on the stick till she was off to my right a little ways, then down and left till she was close enough for these old eyes to see clearly what way she was facing. THEN she reestablished 21 satellites. Unnerved, I just brought her back to my hand. I wonder if I flew between two distant microwave communication towers or something.
ALWAYS stay within sight. That's just an extra backup in case something stops working or the video signal goes away or or or...

It sounds like you have a compass that has become magnetized. There are many reports about just what you describe. My advice is to use a device like CFixer  (Google it  for more info) Available on Amazon--I just bought one. Read  instructions carefully, and you may need to buy a cable to power it. Also recalibnrate your IMU. Good luck.

Flygmaskin Posted at 8-19 23:39
Am I doing something wrong?

Here we go again.. Yaw error, Compass error IMU Heading error.. Exit P-GPS mode.. Whent into ATTI for about 20 seconds. No problem, I could bring it down and control it. Got back the GPS reception, and AC behaved as it should. Then I made a stupid mistake to trust it enough to send it back up. Very high up actually. Higher than I should or can recommend. I must have lost track of the altitude, just marveling at the view and checking the sat count.

Hi,

Great that you 'survived' a double ATTI attack and still have your SPARK.

At 1m18s a YAW error, SW kills the use of GPS and ATTI is there.

IMO the warning "Compass Error. Exit P-GPS Mode" is a general message, it should read YAW error, but not important at all because it always ends to ATTI
YAW signal is used in the IMU, will affect compass ofcourse as IMU has no clue how the drone yaws irt to the heading.

I had same issues with my SPARK, did a IMU and Compass calibration and all OK.

I always do my compass calibr real slow, i mean reeaaall ssslllooooowwww.
(360 turning level and 360 nose down slowly!, in an open green field, no metal close by and RC not close. Just activate on the RC and walk some distance, than watch the lights on Spark to go to the next 360)

DJI should change some messages, this one "IMU heading error. Please restart the aircraft" is shown flying at 286 meters high!! (oops, that too high...)
I suggest for DJI "IMU heading error. Please land the aircraft ASAP !!"
Good Luck!


cheers
JJB

JJB* Posted at 8-21 03:04
Hi,

Great that you 'survived' a double ATTI attack and still have your SPARK.
[Image]

Make that tripple ATTI attack

Survived this one as well.

I did calibrate the compass and the IMU. Way out in the open. Got rid of all the metal I could. Compass showed up to 300 something in interference before the (slooooow as suggested) calibration. 10-20 after. Thought I was good to go, but alas..

Kept Spark in VLOS at all times, and I’m sorry to say that I start to get used to ATTI by now, so despite pretty strong winds, this episode wasn’t as startling. Got it back, regained GPS, and then tried to provoke the compass/yaw error again by going inte sports mode and going full speed, sharp turns, rotate, ascend/descend.. Nope, kept flying fine.

I will check the log when I find the time. Sadly, I’m not at all impressed by this particular DJI Spark at the moment. I can hardly keep it, since it’s just a matter of time until I will loose it in ATTI caused by the errors. Not sure if the retailer will take it back though. Also, I don’t want them to sell this unit to another customer.

The same thing will happen to the next potential owner of this AC. Worst case scenario it will be a person with no prior flight experience, making him/her loose the AC in a flyaway at best, or ending up hurting people or property.

I have sent in and asked DJI to review logs and .dat file and they quickly responded and gave me a case number. I do hope they can come up with an explanation and proper fix.

So bummed out at the moment..

Thank you all for your tips and suggestions, they are most appreciated!

BTW, here’s a picture of the place I did the calibration in. 2 forum points if you spot me

Bag with accessories and belongings, including cellphone, keys, wallet you name it, were left 15 meters from the AC.

And yeah, one might say that the rocks in the place might contain iron.. But I feel the most probable explanation for the errors lay elsewhere.

Issue confirmed as warranty case!

As I said in the previous post, I asked DJI to review the data logs and they did. Got pretty fast response, and they asked (strongly adviced) that I sent the Spark in for diagnostic and service.

I however chosed not to. Instead I took it to the retailer and gave them the full story, showed them the correspondence with DJI and they took the AC and the Fly more combo back, refunding me in full.

The thing is that this particular Spark was a refurbished unit, having made a trip to the service center at some time (no idea for what though), where they repaired/fixed and resetted it. I bought it for reduced prize from the retailer, which clearly said that it had been serviced and was 'as good as new'. When I got it home, I was prompted to activate the AC and I got the opportunity to buy Care Refresh.

The S/N inside the AC didn't match the one on the original black case it came with, so I figure the service center either swapped the AC for another, or they gave it a new S/N before they sent it back to the retailer. I gave DJI the S/N on the case, figuring it might help them to track the AC, if it was the same one as they had previously serviced. Who knows, it might have been serviced for yaw and compass errors before..

Since I didn't send the AC in for service, I can not be sure that DJI would have fixed/replaced it under warranty, but that's the impression I got from the message from the tech support:

Dear Customer,


Thanks for your patience.

The unfortunate incident that occurred to your aircraft has been confirmed as a warranty case according to our data analysis. We strongly advise that you send back the aircraft for diagnostic and service if needed. If you want to send it back, please email me.

Should you have more questions about the result of the data analysis, please reply to this email directly within 15 calendar days. Then we will contact you via email in 2-3 working days.

Thank for your support, have a nice day!

Best Regards,

DJI Technical Support

I update on this, hoping that someone else that might be in the same situation may have help from it. Just do what I did, restore factory defaults through the DJi Assistant 2, downgrade FW, upgrade FW, refresh FW, calibrate the compass (preferably in your underwear in the middle of a football field) check all the sensors, take off from the same football field, and if you still get yaw/compass errors 'IMU Heeding error - please restart the aircraft' (please don't restart the aircraft while in mid-air..) followed by ATTI-mode, STOP flying the AC and contact DJI by sending them the data logs/flight records and ask them what's wrong.

And as for the retailer I returned the defective AC to, I strongly asked them not to resell it to another customer, explaining that if they do, there is a high probability that someone will have a very sad experience while watching their shiny new and expensive tech fly away due to yaw/compass/GPS failure. They said that they wouldn't resell it, but send the AC to DJI as faulty. I gave them copies of my correspondence with the tech support, case number and all, so that they could include it in the shipment, so the service center can have the info and probably the logs.

This particular Spark did not give me as much fun and amusement that I had hoped for.. On the plus side, it did teach me a little bit of how to operate the AC in ATTI-mode. Thankfully I got it back. But I do share the frustration with the ppl who didn't have the same luck and lost their AC due to this error.

Hello to everyone,

Don't want to post new topic couse my friend had very similar problem, unfortunatelly he lost his spark and still can't find it.
On Saturday he flew his drone in the park in the city. It was his 2nd fly this day in this place (2nd battery) and also he flew there the day before without any problems.
After almost 12 minutes he got inbformation about problems with compass (Im not sure what exactly but he will send me a screen) and drone started to fly without any control. He told me that tried to land but it gone away. We have try to find it in place where lost contact with my drone over the roofs and on the ground but we have found nothing.

Here is a log
https://app.airdata.com/flight/a9c142d4d02c16eb9a9bd68a01d64125/GENERALNotifications

I noticed in log, that drone changed mode in atti at 11:50 and than start to go straight.

He has bought it 3 months ago, has DJI Care but probably (Im not sure didnt check it myself) have to find drone first.

Can You tell us what happend and what to do next (still has guarantee too)? How he can find it? He tried with mode "find my drone" but it shaw the same localization as in log file (place where transmieter lost signal with drone).

Maybesmb know, in case like this drone would land if battery is low itself or just flying to battery level 0% and fall on ground?

djiuser_uCznKgiMr9ck Posted at 9-24 07:04
Hello to everyone,

Don't want to post new topic couse my friend had very similar problem, unfortunatelly he lost his spark and still can't find it.

Hi there,

So sorry to hear about the flyaway! It sure sucks.. I was very close myself several times to loose it thanks to it going to ATTI-mode.

In ATTI, it's a way different thing to control the aircraft, since there is no GPS (the GPS is what makes the AC able to stay still in the wind), the AC will go with the wind, and it will go fast! Therefore, the pilot will have to compensate for this, with manual input on the control sticks.

This day, you did not have very much wind (according to the log), atleast on the ground level, but ~120-130 m up is a different story.

As far as I know, yes, your friend must find the drone in order to use the DJI care. But he can always try to submit a data log to DJI and ask them to check it.

The Spark will auto land when the battery is low enough. No fixed battery % value of when this will happen I think, but the smart battery calculates this depending on distance/altitude and some other factors.

Anyway, lots of errors in that log!

11m 49s comes first Yaw Error (repeated 12 times)
11m 50s Here comes Atti, and the Spark is imediately taken by the wind.
11m 50s more yaw error (repeated 10 times)
11m 51s Yaw Error. Magnetic Filed Interference

The magnetic interference warning is something I never got in my logs. I am not as skilled as some other people here, so I can't say for sure if this was an actual real problem, or just an error that the AC throwed, after the yaw error.

Having said that, it is possible that your buddy caught some magnetic interference on the ground. Looks like he took off from ground made of stone, close to asphlat and perhaps close to parked cars? If there is concrete around, there is almost always metall bars in the concrete. You should always, each and every time, make sure that no metal objects are close. As I understand it, the AC compass can pick up the interference, compensate for it in some way, and when you are up in the air, getting away from the interference, the compass will go crazy.

In this case, I find it unlikely that he caught too much  magnetic interference on the ground, since he made a long flight, going both high and far away.

Different from my problem, is also that he didn't get a compass error, no IMU error either.

Anyway, your and his best bet is to try to find the drone ASAP!

I wouldn't look anymore at the place last recorded by the AC. The thing is that at 12m 58s he lost connection from the remote to the AC. Meaning he was too far away to get reception, or getting blocked by trees/interfered by wifi/radio signals coming from the houses below.

Six seconds later, at 13m 04s, the battery is at 19% and this is the last thing transmitted by the drone that he picked up. Nothing about auto landing or critical battery yet. And he is still 139m up!

Checking the log, the AC moves in average ~7 meters per second in the wind, this means that the Spark will have gone a long way from the position, and it will probably followed the straight line it made on the map, seems like the wind direction was concistent.

The manual does not cover what happens when you loose connection while in ATTI-mode, but some users report that it will auto land in 3 seconds. Also, his battery was low, so a auto land could not have been far away, and auto landing will be triggered by this also.

If he is lucky, the AC regained GPS-mode, then it will land steadily. If still in ATTI while landing, it will still go fast in the wind directions, and visual sensors is not working, so then it's high risk of a crash. He might have DJI care though, so finding it is important.

I am not good at calculating wind speeds/distance/descent and give estimates as to where it might have landed, but there are guys at some other forums that are really good at this.

Also, can you please upload the log to https://www.phantomhelp.com/LogViewer/Upload/ it might show more data.

Super hard thing still, but good thing you have a drone and can help him search for it! I would start around here: https://goo.gl/maps/HpX82EezC5aELBtT9 and fly in kind of a straight line, both back and forth.

I wish you the best of luck!

djiuser_uCznKgiMr9ck Posted at 9-24 07:04
Hello to everyone,

Don't want to post new topic couse my friend had very similar problem, unfortunatelly he lost his spark and still can't find it.

Hiya,

In ATTI after some seconds a SPARK  will autoland, with 20% batt last record guess it made it to he ground.
Hard to tell where, must be between last red point to the orange marker.

Hope you have your your mobile phone number on the Spark or your adress ect on the SD card....

Good luck finding your Spark!
cheers
JJB

Thanks Guys.

We tried to find in place where he lost signal also from above with my phantom obisiadian, but we did't find it. Also calculate placees where spark probably was with 10 and 0% of battery, colegue tried to find drone there himself and put some ads but nothing.
He told there wasn't cars in place where he started, as on map it is park and one big building.

Big question is still if he tried to land himself (if so at what battery level).

I tried earlier with phantomhelp site with log, but no more news found there.

Good news is that he sent all his logs to DJI and they reply that drone is missed without any mistakes made by pilot and probably will send newone.

Thank You very much for Your involvement guys.

Best Regards!

djiuser_uCznKgiMr9ck Posted at 10-8 06:22
Thanks Guys.

We tried to find in place where he lost signal also from above with my phantom obisiadian, but we did't find it. Also calculate placees where spark probably was with 10 and 0% of battery, colegue tried to find drone there himself and put some ads but nothing.

Your Big question has been answered, In ATTI loosing RC contact SPARK will autoland after few seconds.

Good luck with the replacement Spark, many happy landings.


cheers
JJB

JJB* Posted at 10-8 06:30
Your Big question has been answered, In ATTI loosing RC contact SPARK will autoland after few seconds.

Good luck with the replacement Spark, many happy landings.

Generally I'm a Phantom 4 pro user and now I start to wonder if Phantom also should land after losing signal i ATTI mode?