Actually my plan worked perfectly
I didn't actually go down to 50ft "over" Halton but just on edge of its ATZ . Whole flight under Atlas 5 mins ....No problems at all . Departing however was different .....I notified them I would be 5 Min late due to terrible traffic ( beyond the 30 mins ) and they just say NO .
Out of interest it was quite late , Elstree was already closed and there was bugger all happening ....so why no leeway ? I got new Plan for 2 hrs later ..lifted off 35 mins early and contacted them whilst en route North and they did not seem put out at all . Surely when I have already flown in I can hardly be seen as a risk flying directly away from London ???
I don't see any need to file a complicated flight plan all the way from the north when you can start one 5 miles outside the restricted zone and keep the freedom of diverting etc on the way down .
Ps Chevron ...I have not bothered register to do flight plans ...but I did state that I would get someone else to do them for me .....much easier that way I find .