jalbert,
If you are still within the 60 minute area and havent crossed the ETOPS threshold, how is this flight any different to a regular 4 engined flight?
A number of our flights are scheduled to operate 3000 nms before entering the ETOPS area of operations, we will treat this initial portion exactly the same as if the flight was terminating in LHR rather than flying over it. We are therefore not worried about adequate airports within 60 minutes, but once we start across the water any airport which was selected as an enroute alternate must remain "suitable".
Mutt.