The weekend of the 7th got binned because it clashes with the Flyer Summer Bash. The 14th got binned because it's the Bastille Day weekend. Tempelhof won't happen because there's only two or three potential participants who could realistically get there and back in a weekend. Those who can make Tempelhof are probably going on the PPL/IR trip there on the first weekend in August anyway.
Unfortunately, although a good idea at the time, splitting the fly-in into two - the European and UK branches - seems to have left too few participants to give each enough momentum. We should consolidate them back into one, fix a date far enough in advance which doesn't clash with anything else (18th August?) and then argue about where we're going to go.