[schubart]

Do all your flights start or end in London?

[jamesharding]

Almost all, but not quite all!

For example, about 6 months ago, I operated the following trip pattern:

LHR -> GIG -> EZE -> GIG -> LHR

The Rio to Buenos Aires and back "shuttle" flight was a day of flying on its own, with 24 hours rest afterwards before flying back to London.