Bolli,
I'm not sure of anything! I stepped outside my back door and looked up, which is standard procedure! I saw this aircraft directly over my head, and almost as soon as I saw it, it banked to the right, starting the move I described in my first post.
The two things that struck me were firstly, when it banked, it was illuminated underneath by the evening sun, and it looked terrific, and secondly, when it turned to the right, my first thought was that it was inbound to Doncaster, 17 miles away, as I have seen other a/c going to Donny on a similar track, although usually a fair bit lower. But it kept turning to the right until it had done a 180, and climbed away south-ish and eventually went out of my sight. What I couldn't understand was a civilian aircraft (as far as I know!) doing such a manoeuvre
That's it! Thanks for the effort, Bolli, and if anyone else has any ideas, sling 'em in!
N.Z.