GSPOT- I like to know I am talking to experienced large jet pilots. Your profile says 'Cessna', which means to me a little high wing thing with a paddle on the front. If it's something heavier, perhaps you would put it in your profile? Then one would know if you were likely to have actually flown into London.
Despite the regulations being large, there are still grey areas. One is the narrow gap between Circling and Sidestep manoeuvres. It takes common sense to assess one from the other. It is not common sense, for example, at LHR to Sidestep, then fly the original GA, taking you over the airport to the other side and overhead what may be traffic taking off from the runway you are not using. Therefore in this, and many other examples, a Circling GA is plainly not common sense- as evidenced by the admission in the MATS regulations that 'this is obviously not a good idea.... so the controller should be prepared for it'. People can argue to the last full stop that it is- it is daft. If other places have local regulations in place, then that's clear.
Intruder has made a clear post with the most sensible set of rules I have see:
Waitaminutehere!
What is the official definition of a "swing over" or "swing across" in CAA/JAA jargon? There is no such official terminology in the US, and I have never heard it before.
In the US there are 4 possibilities for changing runways:
1) Change to the ILS for the new runway, if you are outside the FAF for the original one. In that case, missed approach would be for the new runway approach.
2) Circle to land on the new runway. In that case, the missed approach would be for the original approach.
3) Sidestep to the parallel runway. This is ONLY valid when the sidestep is published for the approach to the original runway. Missed approach is still for the original approach.
4) Visual approach to the parallel runway. Since you are now visual, missed approach will be per ATC (Tower) instructions.
So is it sensible for a pilot to assume that in (4) he should do, what would be utterly stupid and fly the original GA, leading a pilot to execute a 90 degree turn overhead LHR, crossing over the other runway turning through 90 degrees, for example. Follow most people's guidance here, and that is what they think he should do. It's a great hole in UK ATC regulations, and it is important because LHR is so overloaded sometimes you literally cannot get a word in to get instructions for a GA, and the controllers instructions may be drowned out by a whistle as 2 other people try and get a word in.