I have read through most of this thread and am still not getting it. Fair enough, I might just be slow. I have found an UA fare from SEA to LHR for $133 (base) with loads of surcharges (all T Class, not sure what that means) which seems to be what one needs. I am desperately trying to figure out how one tricks this...and I'm clueless even after reading through this thread... I have thrown a number of stops into it - I really am guessing. The added charges stay there.