Viking-Pilot Posted at 2017-10-5 08:55
Scary, did you notice if you were flying near some metal structures or something? I think i was near a streetlight...don't know if that has something to do with it.

It occurred while I was flying in my backyard.  No significant metal structure (house is primarily lumber).  The impact of metal and/or power lines would more likely be on the compass and GPS systems.

djiuser_Kf4iPA3 Posted at 2017-10-5 08:57
That exact same thing happened to me today too, several times. Luckily it was daytime and I was flying VLOS so I could see the aircraft was still responding to the RC, but the video image and flight data were frozen and I couldn't take photos or start a video - even with the RC buttons.
i guided the AC to landing with no problem, same as always. Without being able to take photos or shoot a video there was no point in remaining airborne anyway.
My phone is pretty old (LG G3 from 2014) and it sometimes overheats, I've noticed some correlation between overheating and that issue. I thought maybe when overheating some of my phone's systems begin to be erratic. Did you see that too?

I have noted that the power (CPU) of the android device is directly related to how well the app functions.  I bought a cheap phone (didn't activate it) thinking it would be my primary device for flying.  Turns out that the DJI GO 4 app consistently and constantly mis-behaves.  I must stress I don't believe this to be a defect with the DJI Go 4 app...  it needs a moderately powerful phone.

On the cheap-@$$ phone, I am unable to perform any quickshots or advanced flying features, and the app frequently crashes.

Questions addressed to DJI.
They are related to the explanation given by DJI Support to me and quoted in post #23.
I'm disturbed by the following part: “The aircraft "leaned" in a specific direction and started to speed up because of this. The movement would have to be conteracted by the pilot.
depending on the "leaning angle" of the unit, a throttle up command will result in a even higher acceleration.”

I find this misleading because abnormal behavior is presented as normal.

My questions are:
Under what circumstances does Spark remain leaned after pitch/roll command and stick returned in neutral position, instead to regain its horizontal level?
When does throttle up command produces “even higher acceleration” in horizontal direction?
How exactly should the pilot handle the “leaning angle” of the unit?

I hope that forum Administrators will provide adequate clarification.

Thanks for sharing!

djiuser_gjLUHKA Posted at 2017-10-5 10:33
Questions addressed to DJI.
They are related to the explanation given by DJI Support to me and quoted in post #23.
I'm disturbed by the following part: “The aircraft "leaned" in a specific direction and started to speed up because of this. The movement would have to be conteracted by the pilot.

And I would add - why does a compass error have to lead to dumping GPS and going into ATTI mode in the first place... Knowing that you can find your orientation based on GPS alone, with a rather simple procedure - why isn't it done? Is it deliberate, or a bug?

djiuser_Kf4iPA3 Posted at 2017-10-5 14:45
And I would add - why does a compass error have to lead to dumping GPS and going into ATTI mode in the first place... Knowing that you can find your orientation based on GPS alone, with a rather simple procedure - why isn't it done? Is it deliberate, or a bug?

First this thread has nothing to do with compass problem, it’s a simple case of flying without gps.

And your theory about flying these drones with only gps is not possible, and dji haven’t deliberately set up their aircraft to fail, it’s already been explained to you what actually happens when there is a problem with compass, there are many reasons that you can have problems with compass and most of these can be avoided, whether there is a bug I don’t know, but I have seen this problem both on spark and Mavic much of it as a result of new users of drones, not all but quite a lot, so what is a rare occurrence becomes blown up from what I see inexperienced drone users.

Yes, I understand that's what happens now, that's exactly why I ask this question - why does it happen this way to begin with? If you ask DJI some questions about ATTI, which is what the message I was answering dealt with, this should be the first one.
And nobody contradicted my offered procedure with something based on physics or engineering, other than saying "not possible, period". I also offered a way to overcome the errors wind would introduce into the correction. You say it's not possible? Say why. Because what I'm offering is well within the capabilities of GPS, and it would have saved some people who are not as great pilots as you, apparently, some flyaways, or at least some scary moments and loss of confidence in Spark.

Yes, this thread is about flying in ATTI. I maintain that many instances in which the AC goes into  ATTI could be avoided with the right procedure in the first place.

That's my input here, I won't raise this in this thread any longer, because people appear to get mad when I dare doubt the gods at DJI with legitimate engineering questions which I think would improve their product.

Really detailed info - thanks for sharing

My thoughts about the thread
Although triggered by bad experience I started this thread with positive spirit and I wish it to remain that way. My case is involved as example (I already mentioned) without the intention of further investigation - with respect and thanks for your helpful comments Hallmark.

I can see the thread as the main purpose to serve as some info source about ATTI while there is no dedicated one and I am glad because many people find it useful. It would be good idea to complete it by discussing expected drone behavior in complicated scenarios like yaw and compass error.

The clarification from DJI is needed because until not provided the users will be entertained by “DJI support” with too free interpretations in style: “it is in ATTI mode... and everything is possible”...

djiuser_gjLUHKA Posted at 2017-10-6 07:58
My thoughts about the thread
Although triggered by bad experience I started this thread with positive spirit and I wish it to remain that way. My case is involved as example (I already mentioned) without the intention of further investigation - with respect and thanks for your helpful comments Hallmark.

Thanks for sharing, loved the video!