A friend of mine could not be dissuaded and has now also bought a Spark (and no Air!).
Himselve to blame.
Today I was there on his first flight and then we evaluated the Flight Records.
Due to the bad experiences with the crash of my Spark a few days earlier, I would recommend him to send the Spark back to the dealer immediately, tell him the problem and buy another one!
What do you say, good decision?

Here is a screenshot from the Flight Records.
Should not happen like that, right?

errors

Sorry my friend.  I love my Spark and have no issues with it.  Might want to make sure he has done his IMU calibration and compass calibration.  All these are important before flight, specially a new one.

speeding back and forth in sport mode at low altitude would likely produce that result with any drone. what is it you or he want to do with these machines? seems like you might do better with a fpv racing drone that you can fly fast and crash hard with.

I agree with the post above.  This may be the wrong sort of drone for what your trying to do with it.

There is no GPS information. Therefore, it could be a good candidate for an evaluation from the technician. Can you have your friend send me a personal message regarding his Spark? I would just like to see if there is more we can do to evaluate before sending in.

Good thing is he didn’t crash!

Solestacz Posted at 2018-2-14 10:10
speeding back and forth in sport mode at low altitude would likely produce that result with any drone. what is it you or he want to do with these machines? seems like you might do better with a fpv racing drone that you can fly fast and crash hard with.

Based on that flight map, I tend to agree with Solestacz.

low altitude and sport mode don't mix well.  Maybe the disconnects were caused by the trees.  Try flying above the trees and see if this fixes your issue.

Thanks for all the answers!
Yes, but the first flight was only a stress test.
He usually will not fly like that (or like FPV), he's more a photographer.
But he heard all the story about the spark errors and I told him a lot of "bad things" (how errors can occur) according to the forum and so he wanted to test his spark.
But I did not think that this error would occur if so many satellites were locked.
Unless it really had to do with sport mode and fast direction changes.
Fortunately, the other errors did not occur (yaw error, compass error, speed error, IMU exception).
But do they still come with this spark?

@DJI-Mark: I can certainly get the complete flight log from him.
And tomorrow we'll try it again. Any tips for trying?
He also has 13 days left to send his spark back. I think he will not take a risk on a new device (repair or something).

@all others: Ok, I think that is a good tipp for tomorrow (over the trees for better GPS).

Sparky_17 Posted at 2018-2-14 10:09
Sorry my friend.  I love my Spark and have no issues with it.  Might want to make sure he has done his IMU calibration and compass calibration.  All these are important before flight, specially a new one.

Ok, that's another thing to do.
I look in the DJI Go-App - Sensors for IMU and Compass and they are green before we start.
But perhaps we had to do the calibration because it's a new drone?

gkrause Posted at 2018-2-14 12:38
Ok, that's another thing to do.
I look in the DJI Go-App - Sensors for IMU and Compass and they are green before we start.
But perhaps we had to do the calibration because it's a new drone?

Given the Spark was made in China, shipped across the world, IMU and Compass calibration should be done as part of the initial set up and this goes for all drones in general.  My opinion anyways.

Try it and lets see how it flies after the calibration.