Not a flyaway, but what happened?

[cozzykim]

I was flying around my brother's house, lost connection, and the Spark did a RTH.

What I can't figure is what happened at the end while precision landing, it went off on a little tour about 30ft from the Home Point, and I had to bring it back manually.

DJI Flight Log Viewer - PhantomHelp.com

There's something odd about that area, I kept getting disconnections and loss of GPS at the furthest point on the flights.
I think it might be interference from a local microwave link mast.

 

[Spark 317]

That may be what I've experienced.

I've flown close to a cell phone tower with a large flag on it's mast with no problems.

On a different location, Itried to take a picture of a water tower with an antenna mast nearby put have no luck.

I can fly the Spark to 80' and it's ok.
I go up to 88' and it disconnects.
Unfortunately it's not high enough to get the picture of the water tower.

 

[cozzykim]

The chimney on the right is what I was hoping to look at from directly above, the mast is directly in line of sight behind it from where I was flying the Spark.
As you can see, there's a hefty 11kV (or maybe higher) power supply to the comms mast too, so the disconnects aren't that much of a surprise.

What I don't understand, is why the Spark went on a little detour backwards, about 25-30ft, as it was auto precision landing back at the Home Point.