Just had a pretty scary experience with my Spark.
I’ve been flying my spark for the past 1.5 years in many places no problem.
Today on my sons 5th birthday I intended to make few photos from the air. My 5yo son and a bunch of his friends were interested and observing from a safe distance.
This was in a remote location in the middle of the forest.
Spark started normally, levitating. No sport mode, 15 satellites, etc, I moved it up with RC and then suddenly it started going really fast, spinning and not responding to RC, gaining height and just flying away in weird patterns. I’ve seen RTH dialog twice - to which I tapped yes, nothing happened, it was still going insanely fast (50mph at one point according to logs) in random patterns. Then connection just dropped (I haven’t seen a spark at this point), and it was gone 
I have been exploring the last known location, but there was nothing there. Also, notice that the altitude was rising just before the last known location, so the spark just flew away it seems and just lost connection at this point.
I loved my Spark, and luckily it didn’t hit any of the kids but knowing that could have happened with that speed is scary.
- How can I help dji developers debug this to maximize the chances of fixing this?
- Does dji help/refund customers who have lost their drones due to situations like this? it looks like a severe software/hardware error
here is the log
https://www.phantomhelp.com/LogViewer/DR42AKCO82XS99WFUZK7/
This “Flyaway” which in reality is not the case, was due to a compass error approx 80 seconds after takeoff. This could be due to a “magnetized” compass. Did you have the aircraft any where near any sort of magnet while in transit? ( Speaker etc… )
The reason for the climb at the end is because you were giving full throttle up.
Thanks @Fly_Dawg for analysis
This “Flyaway” which in reality is not the case
This was my first post, did a bit of research since then seems like there are a lot of incidents like this. As a software engineer, I cannot comprehend the reason for this.
If there is a “Compass Error” (or any high level of this type), the system should say that on RC - and land. After a closer look at the logs, the first “Compass Error” occurs just a few feet away from “Home” location. I don’t understand the reasoning behind flying at 20-50mph in random patterns, unresponsive. This looks like a severe bug or lack of logic for handling edge cases like this.
To put this differently.
Imagine going in your car, and instead of engine control blinking and safe mode kicking in (reducing the speed) - the vehicle would speed up with steering wheel being unresponsive. That does not make any sense.
I find this very concerning, and it erodes my trust in Dji products.
According to the logs, you did get the warning. These are the messages that are sent to the display screen. Very close to the home point to begin with.
From looking at the flight, I will grant you that control is most difficult when the compass is thrown off, however with the exception of during signal loss ( Which there is no way to know for certain during those periods ) You had full control of the aircraft and it was responding to your control inputs appropriately. This is especially true at the end of the data file. According to the data, the aircraft never switched to ATTI mode, which in most cases such as this it will. However, that said, it does appear that it was reacting as if it were in ATTI mode.
Thanks again @Fly_Dawg for the analysis
Any idea how they are shown on UI?
The only dialogs I’ve seen during this incident where information that drone is RTH after it went crazy, to which I could only tap OK. There was nothing else that would stop me from flying in the early phase where it was behaving normally (start, levitating and giving it some altitude).
My thinking is that since Compass is the fundamental part of the flying mechanism, allowing the user to fly at this point or creating safety mechanisms that base on Compass is unreasonable.
Curious, what makes you say that? I cannot agree with that 
I was not touching the controls and the drone was going crazy - you can see it here from the logs
also, do you know what is the “Speed Error”? which occurs early
Some other questions that bother me:
- Why 20-50mph? sport mode was off
- Since there was a Compass Error why no ATTI mode?
- and since the connection was lost finally, why not RTH, stop or just land. What’s the point of flying further and further in strange patterns?
- the data shows ~50mph in a few points, isn’t the max speed of spark 31mph?
Take note that during the flight in the replay you posted that the time you are not touching the controls is during the signal loss portions. There is no data for that. That is why you see the sticks stationary.
If you look at the graph above you will see an approx. 16 second signal loss immediately at the first RTH attempt ( Which will not complete with a compass error ) and again towards the end of the data for approx 25 seconds. There are other very short losses as well ( less than 3 seconds each ). Every place else in the data has control inputs and aircraft response.
This is related to the IMU calculations for positioning and speed, with reference to the compass. That is seen often with compass errors.
Sport mode has nothing to do with the speed calculations. That 50mph was recorded immediately upon regaining signal and most likely a calculation error.
Can’t tell from this data set, however you must lose uplink before RTH or Autoland will initiate automatically. It is possible that you only lost downlink.
For reference, if you wish a bit more data, if I am not mistaken, the Spark also records a .dat file on the mobile device. See the link below for instructions. It may provide additional data that is not in the .txt file.
Also, if he has the time I will reference you to @BudWalker for the IMU data for a more in depth look.
Retrieve a V3 DAT
Almost forgot…the file you are looking for I believe is FLY053.DAT.
