Still not sure how you get such a great distance gavie! i took my spark out yesterday, phone aeroplane connected via OTG and flew it straight up i got it to 397ft before it completely lost signal and flew RTH.
I was standing under it the whole time remote pointing at it! maybe london just has way to much wifi hopefully flying in dover this weekend will be a bit better!
Google Maps
That sucks. Got to 1200ft up without trying the other day.